Nos publications
Cervantes-Martinez, Claudia Violeta; Stebe, Marie-Jose; Emo, Melanie; Lebeau, Benedicte; Blin, Jean-Luc Hierarchical mesoporous silica templated by the combination of fine emulsion and micelles Article de journal Microporous and Mesoporous Materials, 305 , p. 110376, 2020. @article{Cervantes-Martinez2020, title = {Hierarchical mesoporous silica templated by the combination of fine emulsion and micelles}, author = { Claudia Violeta Cervantes-Martinez and Marie-Jose Stebe and Melanie Emo and Benedicte Lebeau and Jean-Luc Blin}, doi = {10.1016/j.micromeso.2020.110376}, year = {2020}, date = {2020-10-01}, journal = {Microporous and Mesoporous Materials}, volume = {305}, pages = {110376}, abstract = {Concentrated emulsions have been widely considered as templates for the preparation of macroporous structures. Replacing concentrated emulsions by fine ones should rather lead to materials having large mesopores. However, fine emulsions were barely investigated for this purpose. On the other hand, mesostructured silica SBA-15 can be prepared from Pluronic P123 micelles according to the cooperative templating mechanism. Starting from mixture of fine emulsion and Pluronic P123 micelles, it is expected to obtain silicas with a controlled hierarchical mesoporosity. The fine emulsion has been formulated from the Kolliphor/Myristate/Water system. To get informations concerning the degree of compatibility between the two surfactants, which can affect the formation of the porous materials, the Kolliphor/P123/water system has been investigated in detail. The structural parameters of the mixed liquid crystal phases have been determined and the mixed micellar structure has been investigated by SAXS. The hierarchical porous silicas have been synthetized combining fine emulsion and Pluronic micellar solution. The materials porosity features strongly depend on the weight proportion between the fine emulsion and the P123 micelles. If this proportion is lower than 5/5, mesoporous silicas present a dual mesoporosity. By contrast, by increasing this proportion the mesopore size distribution only shows large mesopores.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Concentrated emulsions have been widely considered as templates for the preparation of macroporous structures. Replacing concentrated emulsions by fine ones should rather lead to materials having large mesopores. However, fine emulsions were barely investigated for this purpose. On the other hand, mesostructured silica SBA-15 can be prepared from Pluronic P123 micelles according to the cooperative templating mechanism. Starting from mixture of fine emulsion and Pluronic P123 micelles, it is expected to obtain silicas with a controlled hierarchical mesoporosity. The fine emulsion has been formulated from the Kolliphor/Myristate/Water system. To get informations concerning the degree of compatibility between the two surfactants, which can affect the formation of the porous materials, the Kolliphor/P123/water system has been investigated in detail. The structural parameters of the mixed liquid crystal phases have been determined and the mixed micellar structure has been investigated by SAXS. The hierarchical porous silicas have been synthetized combining fine emulsion and Pluronic micellar solution. The materials porosity features strongly depend on the weight proportion between the fine emulsion and the P123 micelles. If this proportion is lower than 5/5, mesoporous silicas present a dual mesoporosity. By contrast, by increasing this proportion the mesopore size distribution only shows large mesopores. |
Bataev, I A; Lazurenko, D V; Bataev, A A; Burov, V G; Ivanov, I V; Emurlaev, K I; Smirnov, A I; Rosenthal, M; Burghammer, M; Ivanov, D A; Georgarakis, K; Ruktuev, A A; Ogneva, T S; Jorge, A M J A novel operando approach to analyze the structural evolution of metallic materials during friction with application of synchrotron radiation Article de journal Acta Materialia, 196 , p. 355–369, 2020. @article{Bataev2020, title = {A novel operando approach to analyze the structural evolution of metallic materials during friction with application of synchrotron radiation}, author = { I. A. Bataev and D. V. Lazurenko and A. A. Bataev and V. G. Burov and I. V. Ivanov and K. I. Emurlaev and A. I. Smirnov and M. Rosenthal and M. Burghammer and D. A. Ivanov and K. Georgarakis and A. A. Ruktuev and T. S. Ogneva and A. M. J. Jorge}, doi = {10.1016/j.actamat.2020.06.049}, year = {2020}, date = {2020-09-01}, journal = {Acta Materialia}, volume = {196}, pages = {355--369}, abstract = {In this study, we describe an experimental setup and a new approach for operando investigation of structural evolution of materials during wear and friction. The setup is particularly suited for testing various friction pairs, including those in which both rubbing bodies are made of metals. The developed device allows circumventing the problems related to significant scattering of X-rays produced by metals and makes it possible using "real samples" in synchrotron beamlines operating in reflection mode. To demonstrate the capabilities of the device and the proposed new approach, an iron-based massive sample was subjected to thousands of friction cycles using a cemented carbide pin. The material was probed with synchrotron X-ray radiation within a few milliseconds after leaving the friction zone. The results of the microstructural and structural analysis, as well as results obtained from diverse mathematical models, allowed us to evaluate several features, including gradual accumulation of defects, microstructural refinement, dislocation density changes, surface layer oxidation, as well as several other phenomena caused by the dry sliding friction process. Mainly, it was possible to conclude that the process of wear occurred due to the cooperative action of oxidation and plastic deformation, which began during the first cycle of frictional interaction and was manifested in increasing the dislocation density, whose type was changed gradually during testing. The number of defects quickly reached a threshold value and subsequently fluctuated around it due to periodically repeated processes of defect accumulation and stress relaxation resulting from material wear. It was also observed that friction led to the quick formation of a mechanically mixed layer, consisting of the sample material and a mixture of two types of iron oxide - hematite and magnetite. The delamination of this layer was probably the primary wear mechanism. (C) 2020 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.}, keywords = {}, pubstate = {published}, tppubtype = {article} } In this study, we describe an experimental setup and a new approach for operando investigation of structural evolution of materials during wear and friction. The setup is particularly suited for testing various friction pairs, including those in which both rubbing bodies are made of metals. The developed device allows circumventing the problems related to significant scattering of X-rays produced by metals and makes it possible using "real samples" in synchrotron beamlines operating in reflection mode. To demonstrate the capabilities of the device and the proposed new approach, an iron-based massive sample was subjected to thousands of friction cycles using a cemented carbide pin. The material was probed with synchrotron X-ray radiation within a few milliseconds after leaving the friction zone. The results of the microstructural and structural analysis, as well as results obtained from diverse mathematical models, allowed us to evaluate several features, including gradual accumulation of defects, microstructural refinement, dislocation density changes, surface layer oxidation, as well as several other phenomena caused by the dry sliding friction process. Mainly, it was possible to conclude that the process of wear occurred due to the cooperative action of oxidation and plastic deformation, which began during the first cycle of frictional interaction and was manifested in increasing the dislocation density, whose type was changed gradually during testing. The number of defects quickly reached a threshold value and subsequently fluctuated around it due to periodically repeated processes of defect accumulation and stress relaxation resulting from material wear. It was also observed that friction led to the quick formation of a mechanically mixed layer, consisting of the sample material and a mixture of two types of iron oxide - hematite and magnetite. The delamination of this layer was probably the primary wear mechanism. (C) 2020 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved. |
Ouachtak, Hassan; Akhouairi, Siham; Haounati, Redouane; Addi, Abdelaziz Ait; Jada, Amane; Taha, Mohamed Labd; Douch, Jamaa 3,4-Dihydroxybenzoic acid removal from water by goethite modified natural sand column fixed-bed: experimental study and mathematical modeling Article de journal Desalination and Water Treatment, 194 , p. 439–449, 2020. @article{Ouachtak2020, title = {3,4-Dihydroxybenzoic acid removal from water by goethite modified natural sand column fixed-bed: experimental study and mathematical modeling}, author = { Hassan Ouachtak and Siham Akhouairi and Redouane Haounati and Abdelaziz Ait Addi and Amane Jada and Mohamed Labd Taha and Jamaa Douch}, doi = {10.5004/dwt.2020.25562}, year = {2020}, date = {2020-08-01}, journal = {Desalination and Water Treatment}, volume = {194}, pages = {439--449}, abstract = {In this paper, a continuous adsorption of 3,4-Dihydroxybenzoic acid (3,4-DHBA) has been studied by using goethite modified natural sand (GMNS) as adsorbent in a fixed-bed column. Scanning electron microscopy coupled with energy-dispersive X-ray analysis, X-ray diffraction and Fourier transform infrared spectroscopy (FTIR), characterized the GMNS surface. The effect of various experimental parameters including pH (5 and 9), flow rate (1, 2, and 3 mL/min) and initial 3,4-DHBA concentration (15, 40 and 60 mg/L) on the transport and adsorption of 3,4-DHBA onto the column were investigated in detail. The obtained result shows that exhaustion time decreased with increasing initial 3,4-DHBA concentration, flow rate and pH. The highest value of adsorbed amount q = 35.66 mg/Kg was obtained from injection of 60 mg/L of initial 3,4-DHBA concentration solution with flow rate}, keywords = {}, pubstate = {published}, tppubtype = {article} } In this paper, a continuous adsorption of 3,4-Dihydroxybenzoic acid (3,4-DHBA) has been studied by using goethite modified natural sand (GMNS) as adsorbent in a fixed-bed column. Scanning electron microscopy coupled with energy-dispersive X-ray analysis, X-ray diffraction and Fourier transform infrared spectroscopy (FTIR), characterized the GMNS surface. The effect of various experimental parameters including pH (5 and 9), flow rate (1, 2, and 3 mL/min) and initial 3,4-DHBA concentration (15, 40 and 60 mg/L) on the transport and adsorption of 3,4-DHBA onto the column were investigated in detail. The obtained result shows that exhaustion time decreased with increasing initial 3,4-DHBA concentration, flow rate and pH. The highest value of adsorbed amount q = 35.66 mg/Kg was obtained from injection of 60 mg/L of initial 3,4-DHBA concentration solution with flow rate |
Marks, Evan A N; Kinigopoulou, Vasiliki; Akrout, Hanene; Azzaz, Ahmed Amine; Doulgeris, Charalampos; Jellali, Salah; Rad, Carlos; Zulueta, Paula Sanchez; Tziritis, Evangelos; El-Bassi, Leila; Ghimbeu, Camelia Matei; Jeguirim, Mejdi Potential for Production of Biochar-Based Fertilizers from Olive Mill Waste in Mediterranean Basin Countries: An Initial Assessment for Spain, Tunisia, and Greece Article de journal Sustainability, 12 (15), p. 6081, 2020. @article{Marks2020, title = {Potential for Production of Biochar-Based Fertilizers from Olive Mill Waste in Mediterranean Basin Countries: An Initial Assessment for Spain, Tunisia, and Greece}, author = { Evan A. N. Marks and Vasiliki Kinigopoulou and Hanene Akrout and Ahmed Amine Azzaz and Charalampos Doulgeris and Salah Jellali and Carlos Rad and Paula Sanchez Zulueta and Evangelos Tziritis and Leila El-Bassi and Camelia Matei Ghimbeu and Mejdi Jeguirim}, doi = {10.3390/su12156081}, year = {2020}, date = {2020-08-01}, journal = {Sustainability}, volume = {12}, number = {15}, pages = {6081}, abstract = {Olive mill wastes continue to be a management challenge due to the large volumes produced, particularly due to their toxicity and impacts on the environment. Thermal conversion through pyrolysis or hydrothermal carbonization techniques can detoxify wastes while conserving nutrient contents. In this work, we produced up-to-date data on olive mill waste flows in Spain, Tunisia, and Greece and characterized representative samples in the laboratory. Assays of thermal conversion of olive mill wastewaters and solid wastes were also performed to understand biochar yields and final properties, and the total quantities of nutrients contained were estimated. Of particular note were the quantities of potassium in Tunisian wastewaters, representing 0.6% of the total mass and an annual flow of approximately 5000 t, and in the Spanish solid wastes, an average of 1.7% of the total mass is potassium, representing an annual flow of approximately 23,000 t. Concerning phosphorus, Spanish solid wastes had the highest contents (0.1%), double that of other countries' wastes. Annually, olive mill wastes from the three countries are estimated to contain approximately 35 x 10(3)tons of potassium and 2.6 x 10(3)tons of phosphorus. With this resource converted to biochar, each year more than 700 km(2)of soils could be enriched in 0.2% carbon with biochar at an application rate of 7 t ha(-1).}, keywords = {}, pubstate = {published}, tppubtype = {article} } Olive mill wastes continue to be a management challenge due to the large volumes produced, particularly due to their toxicity and impacts on the environment. Thermal conversion through pyrolysis or hydrothermal carbonization techniques can detoxify wastes while conserving nutrient contents. In this work, we produced up-to-date data on olive mill waste flows in Spain, Tunisia, and Greece and characterized representative samples in the laboratory. Assays of thermal conversion of olive mill wastewaters and solid wastes were also performed to understand biochar yields and final properties, and the total quantities of nutrients contained were estimated. Of particular note were the quantities of potassium in Tunisian wastewaters, representing 0.6% of the total mass and an annual flow of approximately 5000 t, and in the Spanish solid wastes, an average of 1.7% of the total mass is potassium, representing an annual flow of approximately 23,000 t. Concerning phosphorus, Spanish solid wastes had the highest contents (0.1%), double that of other countries' wastes. Annually, olive mill wastes from the three countries are estimated to contain approximately 35 x 10(3)tons of potassium and 2.6 x 10(3)tons of phosphorus. With this resource converted to biochar, each year more than 700 km(2)of soils could be enriched in 0.2% carbon with biochar at an application rate of 7 t ha(-1). |
Anokhin, D V; Grafskaia, K N; Ivanov, D A; Ivan'kova, E M; Marikhin, V A; Myasnikova, L P; Ivanchev, S S Pattern of Monoclinic Phase Distribution in Nascent UHMWPE Particles Article de journal Physics of the Solid State, 62 (8), p. 1493–1499, 2020. @article{Anokhin2020, title = {Pattern of Monoclinic Phase Distribution in Nascent UHMWPE Particles}, author = { D. V Anokhin and K. N. Grafskaia and D. A. Ivanov and E. M. Ivan'kova and V. A. Marikhin and L. P. Myasnikova and S. S. Ivanchev}, doi = {10.1134/S1063783420080028}, year = {2020}, date = {2020-08-01}, journal = {Physics of the Solid State}, volume = {62}, number = {8}, pages = {1493--1499}, abstract = {By using the ID13 nanofocus beamline of the European Synchrotron Radiation Facility (Grenoble, France), an X-ray diffraction study of a "virgin" particle of ultra-high molecular weight polyethylene (UHMWPE) taken directly from the powder synthesis products and not subjected to any external mechanical action was carried out. The X-ray diffraction curves obtained by scanning a randomly selected region of the particle 100 x 20 mu m in size with a 0.3 x 0.3 mu m microbeam with a horizontal step of 2 mu m and vertical step of 0.5 mu m exhibited reflexes from the metastable monoclinic phase along with reflections from the orthorhombic phase. It can be supposed that it could be caused by the stresses that developed at specific structure formation during slurry synthesis and were preserved at cooling to room temperature and solvent evaporation. The possibility of the monoclinic phase localization in various morphological formations is discussed.}, keywords = {}, pubstate = {published}, tppubtype = {article} } By using the ID13 nanofocus beamline of the European Synchrotron Radiation Facility (Grenoble, France), an X-ray diffraction study of a "virgin" particle of ultra-high molecular weight polyethylene (UHMWPE) taken directly from the powder synthesis products and not subjected to any external mechanical action was carried out. The X-ray diffraction curves obtained by scanning a randomly selected region of the particle 100 x 20 mu m in size with a 0.3 x 0.3 mu m microbeam with a horizontal step of 2 mu m and vertical step of 0.5 mu m exhibited reflexes from the metastable monoclinic phase along with reflections from the orthorhombic phase. It can be supposed that it could be caused by the stresses that developed at specific structure formation during slurry synthesis and were preserved at cooling to room temperature and solvent evaporation. The possibility of the monoclinic phase localization in various morphological formations is discussed. |
Chor, Ana; Goncalves, Raquel Pires; Costa, Andrea Machado; Farina, Marcos; Ponche, Arnaud; Sirelli, Lys; Schrodj, Gautier; Gree, Simon; de Andrade, Leonardo Rodrigues; Anselme, Karine; Dias, Marcos Lopes In Vitro Degradation of Electrospun Poly(Lactic-Co-Glycolic Acid) (PLGA) for Oral Mucosa Regeneration. Article de journal Polymers, 12 (8), 2020. @article{Chor2020, title = {In Vitro Degradation of Electrospun Poly(Lactic-Co-Glycolic Acid) (PLGA) for Oral Mucosa Regeneration.}, author = { Ana Chor and Raquel Pires Goncalves and Andrea Machado Costa and Marcos Farina and Arnaud Ponche and Lys Sirelli and Gautier Schrodj and Simon Gree and Leonardo Rodrigues de Andrade and Karine Anselme and Marcos Lopes Dias}, doi = {10.3390/polym12081853}, year = {2020}, date = {2020-08-01}, journal = {Polymers}, volume = {12}, number = {8}, abstract = {Poly(lactic-co-glycolic acid) (PLGA) has been used in the field of tissue engineering as a scaffold due to its good biocompatibility, biodegradability and mechanical strength. With the aim to explore the degradability of PLGA electrospun nonwoven structures for oral mucosa tissue engineering applications, non-irradiated and gamma irradiated nonwovens were immersed in three different solutions, in which simulated body fluid (SBF) and artificial saliva are important for future oral mucosa tissue engineering. The nonwovens were immersed for 7, 15 and 30 days in SBF, culture media (DMEM) and artificial saliva at 37 °C. Before immersion in the solutions, the dosage of 15 kGy was applied for sterilization in one assay and compared with non-irradiated samples at the same timepoints. Samples were characterized using different techniques such as scanning electron microscopy (SEM), differential scanning calorimetric (DSC) and gel permeation chromatography (GPC) to evaluate the nonwoven degradation and Fourier-transform infrared spectroscopy (FTIR) to evaluate the chain scissions. Our results showed that PLGA nonwovens were constituted by semicrystalline fibers with moderate degradation properties up to thirty days. The non-irradiated samples exhibited slower kinetics of degradation than irradiated nonwovens. For immersion times longer than 7 days in the three different solutions, the mean diameter of irradiated fibers stayed in the same range, but significantly different from the control sample. On non-irradiated samples, the degradation kinetics was slower and the plateau in the diameter value was only attained after 30 days of immersion in the fluids. Plasticization (fluid absorption into the fiber structure) occurred in the bulk material, as confirmed by a decrease in Tg observed by DSC analyses of non-irradiated and irradiated nonwovens, in comparison with the respective controls. In addition, artificial saliva showed a higher capacity of influencing PLGA crystallization than SBF and DMEM. FTIR analyses showed typical PLGA chemical functional groups changes. These results will be important for future application of those PLGA electrospun nonwovens for oral mucosa regeneration.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Poly(lactic-co-glycolic acid) (PLGA) has been used in the field of tissue engineering as a scaffold due to its good biocompatibility, biodegradability and mechanical strength. With the aim to explore the degradability of PLGA electrospun nonwoven structures for oral mucosa tissue engineering applications, non-irradiated and gamma irradiated nonwovens were immersed in three different solutions, in which simulated body fluid (SBF) and artificial saliva are important for future oral mucosa tissue engineering. The nonwovens were immersed for 7, 15 and 30 days in SBF, culture media (DMEM) and artificial saliva at 37 °C. Before immersion in the solutions, the dosage of 15 kGy was applied for sterilization in one assay and compared with non-irradiated samples at the same timepoints. Samples were characterized using different techniques such as scanning electron microscopy (SEM), differential scanning calorimetric (DSC) and gel permeation chromatography (GPC) to evaluate the nonwoven degradation and Fourier-transform infrared spectroscopy (FTIR) to evaluate the chain scissions. Our results showed that PLGA nonwovens were constituted by semicrystalline fibers with moderate degradation properties up to thirty days. The non-irradiated samples exhibited slower kinetics of degradation than irradiated nonwovens. For immersion times longer than 7 days in the three different solutions, the mean diameter of irradiated fibers stayed in the same range, but significantly different from the control sample. On non-irradiated samples, the degradation kinetics was slower and the plateau in the diameter value was only attained after 30 days of immersion in the fluids. Plasticization (fluid absorption into the fiber structure) occurred in the bulk material, as confirmed by a decrease in Tg observed by DSC analyses of non-irradiated and irradiated nonwovens, in comparison with the respective controls. In addition, artificial saliva showed a higher capacity of influencing PLGA crystallization than SBF and DMEM. FTIR analyses showed typical PLGA chemical functional groups changes. These results will be important for future application of those PLGA electrospun nonwovens for oral mucosa regeneration. |
Haddad, Khouloud; Jeguirim, Mejdi; Jellali, Salah; Thevenin, Nicolas; Ruidavets, Lionel; Limousy, Lionel Biochar production from Cypress sawdust and olive mill wastewater: Agronomic approach. Article de journal The Science of the total environment, 752 , p. 141713–141713, 2020. @article{Haddad2020, title = {Biochar production from Cypress sawdust and olive mill wastewater: Agronomic approach.}, author = { Khouloud Haddad and Mejdi Jeguirim and Salah Jellali and Nicolas Thevenin and Lionel Ruidavets and Lionel Limousy}, doi = {10.1016/j.scitotenv.2020.141713}, year = {2020}, date = {2020-08-01}, journal = {The Science of the total environment}, volume = {752}, pages = {141713--141713}, abstract = {Olive mill wastewater (OMW) is nowadays considered as a serious source pollution. At the same time, it contains high amounts of nutrients, especially potassium and phosphorus that could be recovered for agricultural purposes. The aim of the current experimental research work is to investigate the agronomic potential use of OMW based biochar produced from the slow pyrolysis at 500°C of raw cypress sawdust (CS) impregnated with OMW (ICS-OMW-B). In order to understand the contribution of OMW, two additional biochars were produced from raw cypress sawdust (RCS-B) and cypress sawdust pretreated with potassium chloride (ICS-K-B). Results indicated that RCS impregnation by OMW significantly improved the produced biochar's chemical properties, especially its nutrients contents. Furthermore, in comparison with the other biochars, ICS-OMW-B application as an organic fertilizer showed promising results in terms of produced fresh and dry masses, as well as potassium bioavailability as assessed in test experiments with ryegrass. For instance, the dry matter masses of the rye-grass treated with ICS-OMW-B were about 23, 34 and 50wt% higher than the ones measured for the tests using RCS-B, ICS-K-B and synthetic K-fertilizer as amendments, respectively. Besides, this biochar has a potential effect on the suppression of various pathogens existing in the tested agricultural soil. All these results demonstrated that the biochar generated from the slow pyrolysis of impregnated sawdust with OMW could be considered as attractive and promising organic fertilizer for acidic agricultural soils.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Olive mill wastewater (OMW) is nowadays considered as a serious source pollution. At the same time, it contains high amounts of nutrients, especially potassium and phosphorus that could be recovered for agricultural purposes. The aim of the current experimental research work is to investigate the agronomic potential use of OMW based biochar produced from the slow pyrolysis at 500°C of raw cypress sawdust (CS) impregnated with OMW (ICS-OMW-B). In order to understand the contribution of OMW, two additional biochars were produced from raw cypress sawdust (RCS-B) and cypress sawdust pretreated with potassium chloride (ICS-K-B). Results indicated that RCS impregnation by OMW significantly improved the produced biochar's chemical properties, especially its nutrients contents. Furthermore, in comparison with the other biochars, ICS-OMW-B application as an organic fertilizer showed promising results in terms of produced fresh and dry masses, as well as potassium bioavailability as assessed in test experiments with ryegrass. For instance, the dry matter masses of the rye-grass treated with ICS-OMW-B were about 23, 34 and 50wt% higher than the ones measured for the tests using RCS-B, ICS-K-B and synthetic K-fertilizer as amendments, respectively. Besides, this biochar has a potential effect on the suppression of various pathogens existing in the tested agricultural soil. All these results demonstrated that the biochar generated from the slow pyrolysis of impregnated sawdust with OMW could be considered as attractive and promising organic fertilizer for acidic agricultural soils. |
Garra, Patxi; Fouassier, Jean Pierre; Lakhdar, Sami; Yagci, Yusuf; Lalevee, Jacques Visible light photoinitiating systems by charge transfer complexes: Photochemistry without dyes Article de journal Progress in Polymer Science, 107 , p. 101277, 2020. @article{Garra2020, title = {Visible light photoinitiating systems by charge transfer complexes: Photochemistry without dyes}, author = { Patxi Garra and Jean Pierre Fouassier and Sami Lakhdar and Yusuf Yagci and Jacques Lalevee}, doi = {10.1016/j.progpolymsci.2020.101277}, year = {2020}, date = {2020-08-01}, journal = {Progress in Polymer Science}, volume = {107}, pages = {101277}, abstract = {Visible light induced synthesis generally involves i) dyes or chromophores with potential photocleavable bonds (Type I photoinitiator), ii) hydrogen abstractions (Type II photoinitiator) by dyes/chromphores and iii) photoredox catalysis using metal-based or metal-free dyes. Beyond these strategies, charge transfer complexes (CTCs), also referred to as electron donor acceptor (EDA) complexes, were also reported to be the visible light initiating species. In these cases, the ground state intimate association of a donor and acceptor creates a new structure that can result in (bathochromic) visible light absorption compared to the separated compounds. In the present review, an update on CTCs as photoinitiating systems for photopoly-merization applications will be provided with examples of CTC-specific structure/reactivity/efficiency relationships. Interestingly, CTC can act as dual photo/thermal photoinitiators both in cationic and free radical photopolymerizations. Also, low optical density of the CTC in resins allowed to access extremely thick samples and composites. The possibility of extending wavelength sensitivity of photopolymerizations by excited state complexes (exciplexes) is also discussed. (C) 2020 Elsevier B.V. All rights reserved.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Visible light induced synthesis generally involves i) dyes or chromophores with potential photocleavable bonds (Type I photoinitiator), ii) hydrogen abstractions (Type II photoinitiator) by dyes/chromphores and iii) photoredox catalysis using metal-based or metal-free dyes. Beyond these strategies, charge transfer complexes (CTCs), also referred to as electron donor acceptor (EDA) complexes, were also reported to be the visible light initiating species. In these cases, the ground state intimate association of a donor and acceptor creates a new structure that can result in (bathochromic) visible light absorption compared to the separated compounds. In the present review, an update on CTCs as photoinitiating systems for photopoly-merization applications will be provided with examples of CTC-specific structure/reactivity/efficiency relationships. Interestingly, CTC can act as dual photo/thermal photoinitiators both in cationic and free radical photopolymerizations. Also, low optical density of the CTC in resins allowed to access extremely thick samples and composites. The possibility of extending wavelength sensitivity of photopolymerizations by excited state complexes (exciplexes) is also discussed. (C) 2020 Elsevier B.V. All rights reserved. |
Narayanan, Lakshmi Kanthan; Sankaranarayanan, Suresh; Rodrigues, Joel J P C; Lorenz, Pascal Multi-Agent-Based Modeling for Underground Pipe Health and Water Quality Monitoring for Supplying Quality Water Article de journal International Journal of Intelligent Information Technologies, 16 (3), p. 52–79, 2020. @article{Narayanan2020, title = {Multi-Agent-Based Modeling for Underground Pipe Health and Water Quality Monitoring for Supplying Quality Water}, author = { Lakshmi Kanthan Narayanan and Suresh Sankaranarayanan and Joel J. P. C. Rodrigues and Pascal Lorenz}, doi = {10.4018/IJIIT.2020070103}, year = {2020}, date = {2020-07-01}, journal = {International Journal of Intelligent Information Technologies}, volume = {16}, number = {3}, pages = {52--79}, abstract = {This article discusses distributed monitoring through the deployment of various multiagents in the IoT-Fog-based water distribution network (WDN). This will ensure the right amount of water supplied with respect to demand forecasted to residents. In addition, underground pipe health is also monitored by means of a multiagent based on hydraulic parameters supplying water forecasted with minimal losses which would minimize the operational and material cost involved in recovery or repair. Lastly, there are agents deployed towards leakage monitoring and anti-theft detection of water. The multiagents act upon various parameters of hydrology and analysis is based on the data acquired by the various sensors deployed in the water distribution network which perform partial automation of the disconnection of the supply during extreme critical conditions.}, keywords = {}, pubstate = {published}, tppubtype = {article} } This article discusses distributed monitoring through the deployment of various multiagents in the IoT-Fog-based water distribution network (WDN). This will ensure the right amount of water supplied with respect to demand forecasted to residents. In addition, underground pipe health is also monitored by means of a multiagent based on hydraulic parameters supplying water forecasted with minimal losses which would minimize the operational and material cost involved in recovery or repair. Lastly, there are agents deployed towards leakage monitoring and anti-theft detection of water. The multiagents act upon various parameters of hydrology and analysis is based on the data acquired by the various sensors deployed in the water distribution network which perform partial automation of the disconnection of the supply during extreme critical conditions. |
del Rios, Carolina Mar Saavedra; Simonin, Loic; de Geyer, Arnaud; Ghimbeu, Camelia Matei; Dupont, Capucine Unraveling the Properties of Biomass-Derived Hard Carbons upon Thermal Treatment for a Practical Application in Na-Ion Batteries Article de journal Energies, 13 (14), p. 3513, 2020. @article{Rios2020, title = {Unraveling the Properties of Biomass-Derived Hard Carbons upon Thermal Treatment for a Practical Application in Na-Ion Batteries}, author = { Carolina del Mar Saavedra Rios and Loic Simonin and Arnaud de Geyer and Camelia Matei Ghimbeu and Capucine Dupont}, doi = {10.3390/en13143513}, year = {2020}, date = {2020-07-01}, journal = {Energies}, volume = {13}, number = {14}, pages = {3513}, abstract = {Biomass is gaining increased attention as a sustainable and low-cost hard carbon (HC) precursor. However, biomass properties are often unexplored and unrelated to HC performance. Herein, we used pine, beechwood, miscanthus, and wheat straw precursors to synthesize HCs at 1000 degrees C, 1200 degrees C and 1400 degrees C by a two-steps pyrolysis treatment. The final physicochemical and electrochemical properties of the HC evidenced dissimilar trends, mainly influenced by the precursor's inorganic content, and less by the thermal treatment. Pine and beechwood HCs delivered the highest reversible capacity and coulombic efficiency (CE) at 1400 degrees C of about 300 mAh center dot g(-1)and 80%, respectively. This performance can be attributed to the structure derived from the high carbon purity precursors. Miscanthus and wheat straw HC performance was strongly affected by the silicon, potassium, and calcium content in the biomasses, which promoted simultaneous detrimental phenomena of intrinsic activation, formation of a silicon carbide phase, and growth of graphitic domains with temperature. The latter HCs delivered 240-200 mAh center dot g(-1)of reversible capacity and 70-60% of CE, respectively, at 1400 degrees C. The biomass precursor composition, especially its inorganic fraction, seems to be a key parameter to control, for obtaining high performance hard carbon electrodes by direct pyrolysis process.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Biomass is gaining increased attention as a sustainable and low-cost hard carbon (HC) precursor. However, biomass properties are often unexplored and unrelated to HC performance. Herein, we used pine, beechwood, miscanthus, and wheat straw precursors to synthesize HCs at 1000 degrees C, 1200 degrees C and 1400 degrees C by a two-steps pyrolysis treatment. The final physicochemical and electrochemical properties of the HC evidenced dissimilar trends, mainly influenced by the precursor's inorganic content, and less by the thermal treatment. Pine and beechwood HCs delivered the highest reversible capacity and coulombic efficiency (CE) at 1400 degrees C of about 300 mAh center dot g(-1)and 80%, respectively. This performance can be attributed to the structure derived from the high carbon purity precursors. Miscanthus and wheat straw HC performance was strongly affected by the silicon, potassium, and calcium content in the biomasses, which promoted simultaneous detrimental phenomena of intrinsic activation, formation of a silicon carbide phase, and growth of graphitic domains with temperature. The latter HCs delivered 240-200 mAh center dot g(-1)of reversible capacity and 70-60% of CE, respectively, at 1400 degrees C. The biomass precursor composition, especially its inorganic fraction, seems to be a key parameter to control, for obtaining high performance hard carbon electrodes by direct pyrolysis process. |
Sprick, Elodie; Graff, Bernadette; Becht, Jean-Michel; Tigges, Thomas; Neuhaus, Kira; Weber, Christoph; Lalevee, Jacques New bio-sourced hydrogen donors as high performance coinitiators and additives for CQ-based systems: Toward aromatic amine-free photoinitiating systems Article de journal European Polymer Journal, 134 , p. 109794, 2020. @article{Sprick2020a, title = {New bio-sourced hydrogen donors as high performance coinitiators and additives for CQ-based systems: Toward aromatic amine-free photoinitiating systems}, author = { Elodie Sprick and Bernadette Graff and Jean-Michel Becht and Thomas Tigges and Kira Neuhaus and Christoph Weber and Jacques Lalevee}, doi = {10.1016/j.eurpolymj.2020.109794}, year = {2020}, date = {2020-07-01}, journal = {European Polymer Journal}, volume = {134}, pages = {109794}, abstract = {Two new hydrogen-donors synthesized from natural products (curcumin and 4-methylumbelliferone) are proposed here as new classes of high performance bio-sourced coinitiators (BHD) for the polymerization of methacrylates under blue light irradiation. In presence of these naturally derived compounds good polymerization performances are reached and good bleaching properties are obtained compared to traditionally used camphorquinone (CQ)-based systems.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Two new hydrogen-donors synthesized from natural products (curcumin and 4-methylumbelliferone) are proposed here as new classes of high performance bio-sourced coinitiators (BHD) for the polymerization of methacrylates under blue light irradiation. In presence of these naturally derived compounds good polymerization performances are reached and good bleaching properties are obtained compared to traditionally used camphorquinone (CQ)-based systems. |
Abdallah, Mira; Hijazi, Akram; Graff, Bernadette; Fouassier, Jean-Pierre; Dumur, Frederic; Lalevee, Jacques In Silico Design of Nitrocoumarins as Near-UV Photoinitiators: Toward Interesting Opportunities in Composites and 3D Printing Technologies Article de journal Acs Applied Polymer Materials, 2 (7), p. 2890–2901, 2020. @article{Abdallah2020c, title = {In Silico Design of Nitrocoumarins as Near-UV Photoinitiators: Toward Interesting Opportunities in Composites and 3D Printing Technologies}, author = { Mira Abdallah and Akram Hijazi and Bernadette Graff and Jean-Pierre Fouassier and Frederic Dumur and Jacques Lalevee}, doi = {10.1021/acsapm.0c00409}, year = {2020}, date = {2020-07-01}, journal = {Acs Applied Polymer Materials}, volume = {2}, number = {7}, pages = {2890--2901}, abstract = {In this research, 31 nitrocoumarins (including 27 structures never reported in the literature) were designed through molecular orbital calculations and synthesized as high-performance near-UV-visible light photoinitiators of polymerization for a better understanding of their structure/reactivity/efficiency relationship. Based on their photoinitiating abilities examined during the free-radical polymerization (FRP) of acrylates, different coumarins examined in this work can be classified into three main categories: (1) very reactive ones (Coum6,7,11,12 & 26); (2) moderately reactive nitrocoumarins (Coum1,2,16,20,21,23,25,27 & 28); and (3) nitrocoumarins of low reactivity (Coum3,4,5,8,9,10,13,14,15,17,18,19,22,24,29,30&31). Different techniques were used in order to understand their photoinitiating abilities as well as the associated chemical mechanisms. The real-time Fourier transform infrared technique has been used to follow the polymerization profiles (reactive function conversion (FCs) vs irradiation time). Different two- and three-component photoinitiating systems based on nitrocoumarin/iodonium salt (or N-phenylglycine (NPG) or ethyl 4-(dimethylamino)benzoate) and nitrocoumarin/iodonium salt/NPG were examined for the FRP of acrylates or/and the cationic polymerization of epoxides upon irradiation with a light-emitting diode at 405 nm as an unharmed and inexpensive irradiation source. Moreover, cyclic voltammetry, fluorescence spectroscopy, UV-visible spectroscopy, and electron spin resonance techniques were also used to provide a full picture of the involved chemical mechanisms. Excellent polymerization performances (i.e., high final reactive FCs and also great rates of polymerization (R-p) were obtained using these derivatives. Some applications in three-dimensional printing and composite synthesis are reported to highlight the interest of the proposed structures in modern technologies.}, keywords = {}, pubstate = {published}, tppubtype = {article} } In this research, 31 nitrocoumarins (including 27 structures never reported in the literature) were designed through molecular orbital calculations and synthesized as high-performance near-UV-visible light photoinitiators of polymerization for a better understanding of their structure/reactivity/efficiency relationship. Based on their photoinitiating abilities examined during the free-radical polymerization (FRP) of acrylates, different coumarins examined in this work can be classified into three main categories: (1) very reactive ones (Coum6,7,11,12 & 26); (2) moderately reactive nitrocoumarins (Coum1,2,16,20,21,23,25,27 & 28); and (3) nitrocoumarins of low reactivity (Coum3,4,5,8,9,10,13,14,15,17,18,19,22,24,29,30&31). Different techniques were used in order to understand their photoinitiating abilities as well as the associated chemical mechanisms. The real-time Fourier transform infrared technique has been used to follow the polymerization profiles (reactive function conversion (FCs) vs irradiation time). Different two- and three-component photoinitiating systems based on nitrocoumarin/iodonium salt (or N-phenylglycine (NPG) or ethyl 4-(dimethylamino)benzoate) and nitrocoumarin/iodonium salt/NPG were examined for the FRP of acrylates or/and the cationic polymerization of epoxides upon irradiation with a light-emitting diode at 405 nm as an unharmed and inexpensive irradiation source. Moreover, cyclic voltammetry, fluorescence spectroscopy, UV-visible spectroscopy, and electron spin resonance techniques were also used to provide a full picture of the involved chemical mechanisms. Excellent polymerization performances (i.e., high final reactive FCs and also great rates of polymerization (R-p) were obtained using these derivatives. Some applications in three-dimensional printing and composite synthesis are reported to highlight the interest of the proposed structures in modern technologies. |
Abdallah, Mira; Hijazi, Akram; Lin, Jui-Teng; Graff, Bernadette; Dumur, Frederic; Lalevee, Jacques Coumarin Derivatives as Photoinitiators in Photo-Oxidation and Photo-Reduction Processes and a Kinetic Model for Simulations of the Associated Polymerization Profiles Article de journal Acs Applied Polymer Materials, 2 (7), p. 2769–2780, 2020. @article{Abdallah2020b, title = {Coumarin Derivatives as Photoinitiators in Photo-Oxidation and Photo-Reduction Processes and a Kinetic Model for Simulations of the Associated Polymerization Profiles}, author = { Mira Abdallah and Akram Hijazi and Jui-Teng Lin and Bernadette Graff and Frederic Dumur and Jacques Lalevee}, doi = {10.1021/acsapm.0c00340}, year = {2020}, date = {2020-07-01}, journal = {Acs Applied Polymer Materials}, volume = {2}, number = {7}, pages = {2769--2780}, abstract = {In this work, the design of an original series of coumarin derivatives CoumC1-CoumC13) is presented. Chemical structures of these coumarins were selected by molecular modeling to ensure both excellent light absorption properties and high potential photoreactivity (high excited-state energy). As a striking result of this in silico design, eight of the 13 proposed coumarins were never presented and were specifically proposed for this work, indicating the interest in their structures. New multicomponent photoinitiating systems (PISs) based on these coumarins are proposed for the free radical polymerization (FRP) of (meth)acrylates and examined upon visible light irradiation using a light-emitting diode (LED) as a safe and economical irradiation source. The proposed systems are based on coumarins that act as remarkable photoinitiators/photosensitizers (PIs/PSs) combined with N-phenyl-glycine (NPG) and/or iodonium salt (Iod) as co-initiators to generate the reactive species (radicals) that will initiate the photopolymerization reaction. Investigations of the chemical mechanisms suggested by the different interactions that take place as well as the photophysical and photochemical properties of coumarins are provided. It is possible to obtain high polymerization rates (R-p), excellent photoinitiating abilities, and great reactive function conversions (FC) with these structures based on the coumarin core. Coumarins show high efficiency for the FRP of (meth)acrylates by reaction with iodonium salt (a photo-oxidation process) or with amine (a photo-reduction process). These compounds were used in three-dimensional (3D) printing resins but also for the preparation of photocomposites. In this latter case, excellent depth of cure was noted as remarkable behavior. To rationalize the experimental results, a kinetic model for a three-component system has been established to analyze the role of oxygen in the monomer conversions and the conversion enhancement observed while using an amine as a co-initiator.}, keywords = {}, pubstate = {published}, tppubtype = {article} } In this work, the design of an original series of coumarin derivatives CoumC1-CoumC13) is presented. Chemical structures of these coumarins were selected by molecular modeling to ensure both excellent light absorption properties and high potential photoreactivity (high excited-state energy). As a striking result of this in silico design, eight of the 13 proposed coumarins were never presented and were specifically proposed for this work, indicating the interest in their structures. New multicomponent photoinitiating systems (PISs) based on these coumarins are proposed for the free radical polymerization (FRP) of (meth)acrylates and examined upon visible light irradiation using a light-emitting diode (LED) as a safe and economical irradiation source. The proposed systems are based on coumarins that act as remarkable photoinitiators/photosensitizers (PIs/PSs) combined with N-phenyl-glycine (NPG) and/or iodonium salt (Iod) as co-initiators to generate the reactive species (radicals) that will initiate the photopolymerization reaction. Investigations of the chemical mechanisms suggested by the different interactions that take place as well as the photophysical and photochemical properties of coumarins are provided. It is possible to obtain high polymerization rates (R-p), excellent photoinitiating abilities, and great reactive function conversions (FC) with these structures based on the coumarin core. Coumarins show high efficiency for the FRP of (meth)acrylates by reaction with iodonium salt (a photo-oxidation process) or with amine (a photo-reduction process). These compounds were used in three-dimensional (3D) printing resins but also for the preparation of photocomposites. In this latter case, excellent depth of cure was noted as remarkable behavior. To rationalize the experimental results, a kinetic model for a three-component system has been established to analyze the role of oxygen in the monomer conversions and the conversion enhancement observed while using an amine as a co-initiator. |
Lebeau, Benedicte; Naboulsi, Issam; Michelin, Laure; Marichal, Claire; Rigolet, Severinne; Carteret, Cedric; Brunet, Sylvette; Bonne, Magali; Blin, Jean-Luc Amorphous mesostructured zirconia with high (hydro)thermal stability Article de journal Rsc Advances, 10 (44), p. 26165–26176, 2020. @article{Lebeau2020, title = {Amorphous mesostructured zirconia with high (hydro)thermal stability}, author = { Benedicte Lebeau and Issam Naboulsi and Laure Michelin and Claire Marichal and Severinne Rigolet and Cedric Carteret and Sylvette Brunet and Magali Bonne and Jean-Luc Blin}, doi = {10.1039/d0ra04824k}, year = {2020}, date = {2020-07-01}, journal = {Rsc Advances}, volume = {10}, number = {44}, pages = {26165--26176}, abstract = {Here, combining the evaporation-induced self-assembly (EISA) method and the liquid crystal templating pathway, mesostructured amorphous zirconium oxides have been prepared by a soft templating method without addition of any heteroelement to stabilize the mesopore framework. The recovered materials have been characterized by SAXS measurements, nitrogen adsorption-desorption analysis and X-ray diffraction (XRD). The obtained mesostructured zirconia exhibits a high thermal stability. Anin situXRD study performed as a function of temperature shows that the amorphous ZrO2, obtained after removal of the pore templating agent (pluronic P123), begins to crystallize in air from 420 degrees C. Amorphous mesostructured ZrO(2)also presents a high hydrothermal stability; these materials are not degraded after 72 hours in boiling water.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Here, combining the evaporation-induced self-assembly (EISA) method and the liquid crystal templating pathway, mesostructured amorphous zirconium oxides have been prepared by a soft templating method without addition of any heteroelement to stabilize the mesopore framework. The recovered materials have been characterized by SAXS measurements, nitrogen adsorption-desorption analysis and X-ray diffraction (XRD). The obtained mesostructured zirconia exhibits a high thermal stability. Anin situXRD study performed as a function of temperature shows that the amorphous ZrO2, obtained after removal of the pore templating agent (pluronic P123), begins to crystallize in air from 420 degrees C. Amorphous mesostructured ZrO(2)also presents a high hydrothermal stability; these materials are not degraded after 72 hours in boiling water. |
Litvinov, Victor; Deblieck, Rudy; Clair, Charles; den Fonteyne, Winke Van; Lallam, Abdelaziz; Kleppinger, Ralf; Ivanov, Dimitri A; Ries, Michael E; Boerakker, Mark Molecular Structure, Phase Composition, Melting Behavior, and Chain Entanglements in the Amorphous Phase of High-Density Polyethylenes Article de journal Macromolecules, 53 (13), p. 5418–5433, 2020. @article{Litvinov2020, title = {Molecular Structure, Phase Composition, Melting Behavior, and Chain Entanglements in the Amorphous Phase of High-Density Polyethylenes}, author = { Victor Litvinov and Rudy Deblieck and Charles Clair and Winke Van den Fonteyne and Abdelaziz Lallam and Ralf Kleppinger and Dimitri A. Ivanov and Michael E. Ries and Mark Boerakker}, doi = {10.1021/acs.macromol.0c00956}, year = {2020}, date = {2020-07-01}, journal = {Macromolecules}, volume = {53}, number = {13}, pages = {5418--5433}, abstract = {A methodology for estimating the entanglement density in the amorphous phase of semicrystalline polyolefins was developed. The method is based on the analysis of the density of physical network junctions in the amorphous phase by H-1 NMR T-2 relaxation experiments. The density of the entanglement network was estimated for melt- and high-pressure-crystallized high-density polyethylenes (HDPEs) at temperatures close to and gradually approaching melting. Its value is lower for high-pressure-crystallized HDPE than for the same melt-crystallized polymer. The network of entanglements is characterized by the fraction of entangled network chains, the weight-average molecular weight of the network chains between apparent chain entanglements, M-e, and the volume average density of apparent chain entanglements. The entanglement network was studied in a series of low- and high-molecular-weight HDPEs and bimodal HDPE samples with different molecular weight characteristics and densities controlled by different contents of the 1-butene comonomer. It turns out that the molecular weight characteristics of the HDPEs influence the entanglement network. The fraction of network chains and the average density of apparent chain entanglements decrease with decreasing molecular weight M-n due to the "dilution" effect caused by disentangled chain-end segments increasing the M-e. The current methodology is of interest for studying the effect of crystallization conditions, molecular structures, and short-chain branches on phase composition, melting behavior, and chain entanglements in the amorphous phase of polyolefins. The method allows estimation of the fraction of network chains, which potentially can form tie-chain segments during deformation. The effect of short-chain branches and molecular weight characteristics on the creep response of polyolefins is discussed.}, keywords = {}, pubstate = {published}, tppubtype = {article} } A methodology for estimating the entanglement density in the amorphous phase of semicrystalline polyolefins was developed. The method is based on the analysis of the density of physical network junctions in the amorphous phase by H-1 NMR T-2 relaxation experiments. The density of the entanglement network was estimated for melt- and high-pressure-crystallized high-density polyethylenes (HDPEs) at temperatures close to and gradually approaching melting. Its value is lower for high-pressure-crystallized HDPE than for the same melt-crystallized polymer. The network of entanglements is characterized by the fraction of entangled network chains, the weight-average molecular weight of the network chains between apparent chain entanglements, M-e, and the volume average density of apparent chain entanglements. The entanglement network was studied in a series of low- and high-molecular-weight HDPEs and bimodal HDPE samples with different molecular weight characteristics and densities controlled by different contents of the 1-butene comonomer. It turns out that the molecular weight characteristics of the HDPEs influence the entanglement network. The fraction of network chains and the average density of apparent chain entanglements decrease with decreasing molecular weight M-n due to the "dilution" effect caused by disentangled chain-end segments increasing the M-e. The current methodology is of interest for studying the effect of crystallization conditions, molecular structures, and short-chain branches on phase composition, melting behavior, and chain entanglements in the amorphous phase of polyolefins. The method allows estimation of the fraction of network chains, which potentially can form tie-chain segments during deformation. The effect of short-chain branches and molecular weight characteristics on the creep response of polyolefins is discussed. |
Diboune, Mathieu; Nouali, Habiba; Soulard, Michel; Patarin, Joel; Rioland, Guillaume; Faye, Delphine; Daou, Jean T Efficient Removal of Volatile Organic Compounds by FAU-Type Zeolite Coatings. Article de journal Molecules (Basel, Switzerland), 25 (15), 2020. @article{Diboune2020, title = {Efficient Removal of Volatile Organic Compounds by FAU-Type Zeolite Coatings.}, author = { Mathieu Diboune and Habiba Nouali and Michel Soulard and Joel Patarin and Guillaume Rioland and Delphine Faye and T. Jean Daou}, doi = {10.3390/molecules25153336}, year = {2020}, date = {2020-07-01}, journal = {Molecules (Basel, Switzerland)}, volume = {25}, number = {15}, abstract = {Silicone and pure organic binders were used to develop FAU-type zeolite coatings applied on pre-treated aluminum substrates by using a spraying method and then cured under specific conditions. The influence of the amount of binder on adhesion properties of zeolite coatings was first investigated to determine the optimum ratio between zeolite and binder. Zeolite coatings were then elaborated with a high zeolite content (between 70 and 80 wt.%) to ensure high adsorption capacities. The amount of binders involved in different zeolite coatings was sufficient to achieve interesting adhesion and cohesion properties. The accessibility of zeolite microporosity was studied by nitrogen adsorption-desorption measurements, which revealed a very small or no loss of the micropore volume for the optimized coatings. Volatile Organic Compounds (VOCs) adsorption measurements were carried out using n-hexane as probe molecule. FAU-type zeolite in powder form adsorbs 180 mg/ganhydrous zeolite, whereas the amounts of n-hexane adsorbed by zeolite coatings ranged from 131 to 175 mg/ganhydrous zeolite.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Silicone and pure organic binders were used to develop FAU-type zeolite coatings applied on pre-treated aluminum substrates by using a spraying method and then cured under specific conditions. The influence of the amount of binder on adhesion properties of zeolite coatings was first investigated to determine the optimum ratio between zeolite and binder. Zeolite coatings were then elaborated with a high zeolite content (between 70 and 80 wt.%) to ensure high adsorption capacities. The amount of binders involved in different zeolite coatings was sufficient to achieve interesting adhesion and cohesion properties. The accessibility of zeolite microporosity was studied by nitrogen adsorption-desorption measurements, which revealed a very small or no loss of the micropore volume for the optimized coatings. Volatile Organic Compounds (VOCs) adsorption measurements were carried out using n-hexane as probe molecule. FAU-type zeolite in powder form adsorbs 180 mg/ganhydrous zeolite, whereas the amounts of n-hexane adsorbed by zeolite coatings ranged from 131 to 175 mg/ganhydrous zeolite. |
Caillosse, Etienne; Zaier, Mohamed; Mezghani, Mariam; Hajjar-Garreau, Samar; Vidal, Loic; Lougnot, Daniel; Balan, Lavinia Photo-Induced Self-Assembly of Silver Nanoparticles for Rapid Generation of First and Second Surface Mirrors Article de journal Acs Applied Nano Materials, 3 (7), p. 6531–6540, 2020. @article{Caillosse2020, title = {Photo-Induced Self-Assembly of Silver Nanoparticles for Rapid Generation of First and Second Surface Mirrors}, author = { Etienne Caillosse and Mohamed Zaier and Mariam Mezghani and Samar Hajjar-Garreau and Loic Vidal and Daniel Lougnot and Lavinia Balan}, doi = {10.1021/acsanm.0c01010}, year = {2020}, date = {2020-07-01}, journal = {Acs Applied Nano Materials}, volume = {3}, number = {7}, pages = {6531--6540}, abstract = {Interesting mirror-like, highly reflective, and conductive silver films have been successfully generated directly on a glass slide using a simple and fast photoinduced approach. A water-based photosensitive formulation containing the silver precursor and a photogenerator of free radicals was used. It was applied like paint and exposed to UV light for a few seconds, in the absence of any additional reducing agents and without further treatment of any kind. This approach allowed ultrathin films of silver nanoparticles to be generated in situ (AgNPs) on the back side of the glass substrate. The particles are homogeneously autoassembled onto the glass surface and the glass/silver diopter exhibits a high reflective character. With such an experimental arrangement, reflective surfaces are obtained: in contact with the glass slide, which is called the second surface mirror, and on the air side, which is called the first surface mirror. Quite interestingly, these reflective and conductive thin films exhibit strong natural adhesion on the glass substrate without the need for enhancing treatments (sensitization or activation) to improve the adhesion of the silver layer to the glass, as usual with silver glass mirrors. The influence of several chemical and photonic parameters has been examined in order to optimize the final optical and electrical properties of these silver films.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Interesting mirror-like, highly reflective, and conductive silver films have been successfully generated directly on a glass slide using a simple and fast photoinduced approach. A water-based photosensitive formulation containing the silver precursor and a photogenerator of free radicals was used. It was applied like paint and exposed to UV light for a few seconds, in the absence of any additional reducing agents and without further treatment of any kind. This approach allowed ultrathin films of silver nanoparticles to be generated in situ (AgNPs) on the back side of the glass substrate. The particles are homogeneously autoassembled onto the glass surface and the glass/silver diopter exhibits a high reflective character. With such an experimental arrangement, reflective surfaces are obtained: in contact with the glass slide, which is called the second surface mirror, and on the air side, which is called the first surface mirror. Quite interestingly, these reflective and conductive thin films exhibit strong natural adhesion on the glass substrate without the need for enhancing treatments (sensitization or activation) to improve the adhesion of the silver layer to the glass, as usual with silver glass mirrors. The influence of several chemical and photonic parameters has been examined in order to optimize the final optical and electrical properties of these silver films. |
Tkachenko, Vitalii; Vidal, Loic; Josien, Ludovic; Schmutz, Marc; Poly, Julien; Chemtob, Abraham Characterizing the Core-Shell Architecture of Block Copolymer Nanoparticles with Electron Microscopy: A Multi-Technique Approach. Article de journal Polymers, 12 (8), 2020. @article{Tkachenko2020b, title = {Characterizing the Core-Shell Architecture of Block Copolymer Nanoparticles with Electron Microscopy: A Multi-Technique Approach.}, author = { Vitalii Tkachenko and Loic Vidal and Ludovic Josien and Marc Schmutz and Julien Poly and Abraham Chemtob}, doi = {10.3390/polym12081656}, year = {2020}, date = {2020-07-01}, journal = {Polymers}, volume = {12}, number = {8}, abstract = {Electron microscopy has proved to be a major tool to study the structure of self-assembled amphiphilic block copolymer particles. These specimens, like supramolecular biological structures, are problematic for electron microscopy because of their poor capacity to scatter electrons and their susceptibility to radiation damage and dehydration. Sub-50 nm core-shell spherical particles made up of poly(hydroxyethyl acrylate)-b-poly(styrene) are prepared via polymerization-induced self-assembly (PISA). For their morphological characterization, we discuss the advantages, limitations, and artefacts of TEM with or without staining, cryo-TEM, and SEM. A number of technical points are addressed such as precisely shaping of particle boundaries, resolving the particle shell, differentiating particle core and shell, and the effect of sample drying and staining. TEM without staining and cryo-TEM largely evaluate the core diameter. Negative staining TEM is more efficient than positive staining TEM to preserve native structure and to visualize the entire particle volume. However, no technique allows for a satisfactory imaging of both core and shell regions. The presence of long protruding chains is manifested by patched structure in cryo-TEM and a significant edge effect in SEM. This manuscript provides a basis for polymer chemists to develop their own specimen preparations and to tackle the interpretation of challenging systems.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Electron microscopy has proved to be a major tool to study the structure of self-assembled amphiphilic block copolymer particles. These specimens, like supramolecular biological structures, are problematic for electron microscopy because of their poor capacity to scatter electrons and their susceptibility to radiation damage and dehydration. Sub-50 nm core-shell spherical particles made up of poly(hydroxyethyl acrylate)-b-poly(styrene) are prepared via polymerization-induced self-assembly (PISA). For their morphological characterization, we discuss the advantages, limitations, and artefacts of TEM with or without staining, cryo-TEM, and SEM. A number of technical points are addressed such as precisely shaping of particle boundaries, resolving the particle shell, differentiating particle core and shell, and the effect of sample drying and staining. TEM without staining and cryo-TEM largely evaluate the core diameter. Negative staining TEM is more efficient than positive staining TEM to preserve native structure and to visualize the entire particle volume. However, no technique allows for a satisfactory imaging of both core and shell regions. The presence of long protruding chains is manifested by patched structure in cryo-TEM and a significant edge effect in SEM. This manuscript provides a basis for polymer chemists to develop their own specimen preparations and to tackle the interpretation of challenging systems. |
Chen, Hong; Noirbent, Guillaume; Sun, Ke; Brunel, Damien; Gigmes, Didier; Morlet-Savary, Fabrice; Zhang, Yijun; Liu, Shaohui; Xiao, Pu; Dumur, Frederic; Lalevee, Jacques Photoinitiators derived from natural product scaffolds: monochalcones in three-component photoinitiating systems and their applications in 3D printing Article de journal Polymer Chemistry, 11 (28), p. 4647–4659, 2020. @article{Chen2020, title = {Photoinitiators derived from natural product scaffolds: monochalcones in three-component photoinitiating systems and their applications in 3D printing}, author = { Hong Chen and Guillaume Noirbent and Ke Sun and Damien Brunel and Didier Gigmes and Fabrice Morlet-Savary and Yijun Zhang and Shaohui Liu and Pu Xiao and Frederic Dumur and Jacques Lalevee}, doi = {10.1039/d0py00568a}, year = {2020}, date = {2020-07-01}, journal = {Polymer Chemistry}, volume = {11}, number = {28}, pages = {4647--4659}, abstract = {The design and development of high-performance photoinitiating systems applicable to visible light delivered from light-emitting diodes (LEDs) attract ever-increasing attention due to their great potential applications in various fields. Chalcones belong to a well-established class of natural compounds present in many plants. In this context, photoinitiators based on the scaffolds of natural compounds have probably great potential to open the way for non-toxic photoinitiators in the manufacturing of biocompatible polymer materials. In this work, 23 different chalcones selected fromin silicomolecular design (i.e.through molecular orbital calculations) were used in conjunction with an aminei.e.ethyl 4-(dimethylamino) benzoate (EDB) and an iodonium salt (bis-(4-tert-butylphenyl)iodonium hexafluorophosphate, Iod) to form photoinitiating systems (PISs) capable of initiating the polymerization of polyethylene glycol (600) diacrylate (PEG-diacrylate)viaan oxidation-reduction reaction mechanism. The formation of hydrogels by the photopolymerization of PEG-acrylate is found to be very efficient. Remarkably, 10 of the 23 chalcones were completely new and even never synthesized prior to this work (chalcones4,5,7,8,9,10,12,15,16and21). By using computational quantum chemistry, fluorescence, steady-state photolysis, and electron spin resonance spin-trapping techniques, the photoinitiation mechanism of three-component photoinitiating systems based on chalcones/Iod/EDB is clarified. The results demonstrate that several chalcone-based PISs can initiate free radical photopolymerization. Moreover, the developed chalcone-based three-component systems are applied to generate 3D hydrogel patterns using the 3D laser write technology. This research provides some novel insights into photopolymerization reactions with three-component photoinitiating systems used for 3D printing of hydrogels.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The design and development of high-performance photoinitiating systems applicable to visible light delivered from light-emitting diodes (LEDs) attract ever-increasing attention due to their great potential applications in various fields. Chalcones belong to a well-established class of natural compounds present in many plants. In this context, photoinitiators based on the scaffolds of natural compounds have probably great potential to open the way for non-toxic photoinitiators in the manufacturing of biocompatible polymer materials. In this work, 23 different chalcones selected fromin silicomolecular design (i.e.through molecular orbital calculations) were used in conjunction with an aminei.e.ethyl 4-(dimethylamino) benzoate (EDB) and an iodonium salt (bis-(4-tert-butylphenyl)iodonium hexafluorophosphate, Iod) to form photoinitiating systems (PISs) capable of initiating the polymerization of polyethylene glycol (600) diacrylate (PEG-diacrylate)viaan oxidation-reduction reaction mechanism. The formation of hydrogels by the photopolymerization of PEG-acrylate is found to be very efficient. Remarkably, 10 of the 23 chalcones were completely new and even never synthesized prior to this work (chalcones4,5,7,8,9,10,12,15,16and21). By using computational quantum chemistry, fluorescence, steady-state photolysis, and electron spin resonance spin-trapping techniques, the photoinitiation mechanism of three-component photoinitiating systems based on chalcones/Iod/EDB is clarified. The results demonstrate that several chalcone-based PISs can initiate free radical photopolymerization. Moreover, the developed chalcone-based three-component systems are applied to generate 3D hydrogel patterns using the 3D laser write technology. This research provides some novel insights into photopolymerization reactions with three-component photoinitiating systems used for 3D printing of hydrogels. |
Tomal, Wiktoria; Pilch, Maciej; Chachaj-Brekiesz, Anna; Galek, Mariusz; Morlet-Savary, Fabrice; Graff, Bernadette; Dietlin, Cline; Lalevee, Jacques; Ortyl, Joanna Polymer Chemistry, 11 (28), p. 4604–4621, 2020. @article{Tomal2020, title = {Photoinitiator-catalyst systems based onmeta-terphenyl derivatives as photosensitisers of iodonium and thianthrenium salts for visible photopolymerization in 3D printing processes}, author = { Wiktoria Tomal and Maciej Pilch and Anna Chachaj-Brekiesz and Mariusz Galek and Fabrice Morlet-Savary and Bernadette Graff and Cline Dietlin and Jacques Lalevee and Joanna Ortyl}, doi = {10.1039/d0py00597e}, year = {2020}, date = {2020-07-01}, journal = {Polymer Chemistry}, volume = {11}, number = {28}, pages = {4604--4621}, abstract = {This work demonstrates a new versatile, efficient photoinitiating system based on 2-amino-4-phenyl-6-(4-phenylphenyl)benzene-1,3-dicarbonitrile and 2-amino-4-phenyl-6-[4-[(E)-styryl]phenyl]benzene-1,3-dicarbonitrile derivatives as photosensitisers of iodonium and thianthrenium salts for photopolymerization under visible low light intensity with potential translation to high performance 3D printing. The newmeta-terphenyl derivatives were characterised by standard analytical and spectroscopic techniques. The activity of new bimolecular photoinitiating systems was investigated using Fourier transform real-time infrared spectroscopy. As the choices for an efficient visible sensitiser are rather limited for thianthrenium salt, the syntheses of new photo-sensitisers have received considerable attention. Therefore, the main goal of this study was to applymeta-terphenyl derivatives as visible photosensitisers for different types of onium salts. For this purpose, the new 2-amino-4-phenyl-6-(4-phenylphenyl)benzene-1,3-dicarbonitrile and 2-amino-4-phenyl-6-[4-[(E)-styryl]phenyl]benzene-1,3-dicarbonitrile derivatives were combined with commercially available iodonium salt (HIP) and thianthrenium salt to create visible light photoinitiating systems. It was shown that the efficiency of these bimolecular photoinitiating systems was based on the favorable free energy change of the photoinduced electron transfer from themeta-terphenyl derivatives to the iodonium and thianthrenium salts. It was confirmed by the experiments that the ability of tested photoredox pairs to initiate the photopolymerization processes depends on the oxidation potentials of themeta-terphenyl derivatives and the reduction potentials of the onium salts. Here, we explore the role of the scientific aspects of the mechanism, energetics and dynamics of applicability of the newmeta-terphenyl compounds as efficient and versatile photosensitisers of onium salts with different oxidising power. Moreover, the investigated terphenyl derivatives can work as photoredox catalysts and efficient photoinitiating systems, and can be used with typical oxidation and reduction agents in both reductive and oxidation cycles.}, keywords = {}, pubstate = {published}, tppubtype = {article} } This work demonstrates a new versatile, efficient photoinitiating system based on 2-amino-4-phenyl-6-(4-phenylphenyl)benzene-1,3-dicarbonitrile and 2-amino-4-phenyl-6-[4-[(E)-styryl]phenyl]benzene-1,3-dicarbonitrile derivatives as photosensitisers of iodonium and thianthrenium salts for photopolymerization under visible low light intensity with potential translation to high performance 3D printing. The newmeta-terphenyl derivatives were characterised by standard analytical and spectroscopic techniques. The activity of new bimolecular photoinitiating systems was investigated using Fourier transform real-time infrared spectroscopy. As the choices for an efficient visible sensitiser are rather limited for thianthrenium salt, the syntheses of new photo-sensitisers have received considerable attention. Therefore, the main goal of this study was to applymeta-terphenyl derivatives as visible photosensitisers for different types of onium salts. For this purpose, the new 2-amino-4-phenyl-6-(4-phenylphenyl)benzene-1,3-dicarbonitrile and 2-amino-4-phenyl-6-[4-[(E)-styryl]phenyl]benzene-1,3-dicarbonitrile derivatives were combined with commercially available iodonium salt (HIP) and thianthrenium salt to create visible light photoinitiating systems. It was shown that the efficiency of these bimolecular photoinitiating systems was based on the favorable free energy change of the photoinduced electron transfer from themeta-terphenyl derivatives to the iodonium and thianthrenium salts. It was confirmed by the experiments that the ability of tested photoredox pairs to initiate the photopolymerization processes depends on the oxidation potentials of themeta-terphenyl derivatives and the reduction potentials of the onium salts. Here, we explore the role of the scientific aspects of the mechanism, energetics and dynamics of applicability of the newmeta-terphenyl compounds as efficient and versatile photosensitisers of onium salts with different oxidising power. Moreover, the investigated terphenyl derivatives can work as photoredox catalysts and efficient photoinitiating systems, and can be used with typical oxidation and reduction agents in both reductive and oxidation cycles. |
2020 |
Cervantes-Martinez, Claudia Violeta; Stebe, Marie-Jose; Emo, Melanie; Lebeau, Benedicte; Blin, Jean-Luc Hierarchical mesoporous silica templated by the combination of fine emulsion and micelles (Article de journal) Microporous and Mesoporous Materials, 305 , p. 110376, 2020. @article{Cervantes-Martinez2020, title = {Hierarchical mesoporous silica templated by the combination of fine emulsion and micelles}, author = { Claudia Violeta Cervantes-Martinez and Marie-Jose Stebe and Melanie Emo and Benedicte Lebeau and Jean-Luc Blin}, doi = {10.1016/j.micromeso.2020.110376}, year = {2020}, date = {2020-10-01}, journal = {Microporous and Mesoporous Materials}, volume = {305}, pages = {110376}, abstract = {Concentrated emulsions have been widely considered as templates for the preparation of macroporous structures. Replacing concentrated emulsions by fine ones should rather lead to materials having large mesopores. However, fine emulsions were barely investigated for this purpose. On the other hand, mesostructured silica SBA-15 can be prepared from Pluronic P123 micelles according to the cooperative templating mechanism. Starting from mixture of fine emulsion and Pluronic P123 micelles, it is expected to obtain silicas with a controlled hierarchical mesoporosity. The fine emulsion has been formulated from the Kolliphor/Myristate/Water system. To get informations concerning the degree of compatibility between the two surfactants, which can affect the formation of the porous materials, the Kolliphor/P123/water system has been investigated in detail. The structural parameters of the mixed liquid crystal phases have been determined and the mixed micellar structure has been investigated by SAXS. The hierarchical porous silicas have been synthetized combining fine emulsion and Pluronic micellar solution. The materials porosity features strongly depend on the weight proportion between the fine emulsion and the P123 micelles. If this proportion is lower than 5/5, mesoporous silicas present a dual mesoporosity. By contrast, by increasing this proportion the mesopore size distribution only shows large mesopores.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Concentrated emulsions have been widely considered as templates for the preparation of macroporous structures. Replacing concentrated emulsions by fine ones should rather lead to materials having large mesopores. However, fine emulsions were barely investigated for this purpose. On the other hand, mesostructured silica SBA-15 can be prepared from Pluronic P123 micelles according to the cooperative templating mechanism. Starting from mixture of fine emulsion and Pluronic P123 micelles, it is expected to obtain silicas with a controlled hierarchical mesoporosity. The fine emulsion has been formulated from the Kolliphor/Myristate/Water system. To get informations concerning the degree of compatibility between the two surfactants, which can affect the formation of the porous materials, the Kolliphor/P123/water system has been investigated in detail. The structural parameters of the mixed liquid crystal phases have been determined and the mixed micellar structure has been investigated by SAXS. The hierarchical porous silicas have been synthetized combining fine emulsion and Pluronic micellar solution. The materials porosity features strongly depend on the weight proportion between the fine emulsion and the P123 micelles. If this proportion is lower than 5/5, mesoporous silicas present a dual mesoporosity. By contrast, by increasing this proportion the mesopore size distribution only shows large mesopores. |
Bataev, I A; Lazurenko, D V; Bataev, A A; Burov, V G; Ivanov, I V; Emurlaev, K I; Smirnov, A I; Rosenthal, M; Burghammer, M; Ivanov, D A; Georgarakis, K; Ruktuev, A A; Ogneva, T S; Jorge, A M J A novel operando approach to analyze the structural evolution of metallic materials during friction with application of synchrotron radiation (Article de journal) Acta Materialia, 196 , p. 355–369, 2020. @article{Bataev2020, title = {A novel operando approach to analyze the structural evolution of metallic materials during friction with application of synchrotron radiation}, author = { I. A. Bataev and D. V. Lazurenko and A. A. Bataev and V. G. Burov and I. V. Ivanov and K. I. Emurlaev and A. I. Smirnov and M. Rosenthal and M. Burghammer and D. A. Ivanov and K. Georgarakis and A. A. Ruktuev and T. S. Ogneva and A. M. J. Jorge}, doi = {10.1016/j.actamat.2020.06.049}, year = {2020}, date = {2020-09-01}, journal = {Acta Materialia}, volume = {196}, pages = {355--369}, abstract = {In this study, we describe an experimental setup and a new approach for operando investigation of structural evolution of materials during wear and friction. The setup is particularly suited for testing various friction pairs, including those in which both rubbing bodies are made of metals. The developed device allows circumventing the problems related to significant scattering of X-rays produced by metals and makes it possible using "real samples" in synchrotron beamlines operating in reflection mode. To demonstrate the capabilities of the device and the proposed new approach, an iron-based massive sample was subjected to thousands of friction cycles using a cemented carbide pin. The material was probed with synchrotron X-ray radiation within a few milliseconds after leaving the friction zone. The results of the microstructural and structural analysis, as well as results obtained from diverse mathematical models, allowed us to evaluate several features, including gradual accumulation of defects, microstructural refinement, dislocation density changes, surface layer oxidation, as well as several other phenomena caused by the dry sliding friction process. Mainly, it was possible to conclude that the process of wear occurred due to the cooperative action of oxidation and plastic deformation, which began during the first cycle of frictional interaction and was manifested in increasing the dislocation density, whose type was changed gradually during testing. The number of defects quickly reached a threshold value and subsequently fluctuated around it due to periodically repeated processes of defect accumulation and stress relaxation resulting from material wear. It was also observed that friction led to the quick formation of a mechanically mixed layer, consisting of the sample material and a mixture of two types of iron oxide - hematite and magnetite. The delamination of this layer was probably the primary wear mechanism. (C) 2020 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.}, keywords = {}, pubstate = {published}, tppubtype = {article} } In this study, we describe an experimental setup and a new approach for operando investigation of structural evolution of materials during wear and friction. The setup is particularly suited for testing various friction pairs, including those in which both rubbing bodies are made of metals. The developed device allows circumventing the problems related to significant scattering of X-rays produced by metals and makes it possible using "real samples" in synchrotron beamlines operating in reflection mode. To demonstrate the capabilities of the device and the proposed new approach, an iron-based massive sample was subjected to thousands of friction cycles using a cemented carbide pin. The material was probed with synchrotron X-ray radiation within a few milliseconds after leaving the friction zone. The results of the microstructural and structural analysis, as well as results obtained from diverse mathematical models, allowed us to evaluate several features, including gradual accumulation of defects, microstructural refinement, dislocation density changes, surface layer oxidation, as well as several other phenomena caused by the dry sliding friction process. Mainly, it was possible to conclude that the process of wear occurred due to the cooperative action of oxidation and plastic deformation, which began during the first cycle of frictional interaction and was manifested in increasing the dislocation density, whose type was changed gradually during testing. The number of defects quickly reached a threshold value and subsequently fluctuated around it due to periodically repeated processes of defect accumulation and stress relaxation resulting from material wear. It was also observed that friction led to the quick formation of a mechanically mixed layer, consisting of the sample material and a mixture of two types of iron oxide - hematite and magnetite. The delamination of this layer was probably the primary wear mechanism. (C) 2020 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved. |
Ouachtak, Hassan; Akhouairi, Siham; Haounati, Redouane; Addi, Abdelaziz Ait; Jada, Amane; Taha, Mohamed Labd; Douch, Jamaa 3,4-Dihydroxybenzoic acid removal from water by goethite modified natural sand column fixed-bed: experimental study and mathematical modeling (Article de journal) Desalination and Water Treatment, 194 , p. 439–449, 2020. @article{Ouachtak2020, title = {3,4-Dihydroxybenzoic acid removal from water by goethite modified natural sand column fixed-bed: experimental study and mathematical modeling}, author = { Hassan Ouachtak and Siham Akhouairi and Redouane Haounati and Abdelaziz Ait Addi and Amane Jada and Mohamed Labd Taha and Jamaa Douch}, doi = {10.5004/dwt.2020.25562}, year = {2020}, date = {2020-08-01}, journal = {Desalination and Water Treatment}, volume = {194}, pages = {439--449}, abstract = {In this paper, a continuous adsorption of 3,4-Dihydroxybenzoic acid (3,4-DHBA) has been studied by using goethite modified natural sand (GMNS) as adsorbent in a fixed-bed column. Scanning electron microscopy coupled with energy-dispersive X-ray analysis, X-ray diffraction and Fourier transform infrared spectroscopy (FTIR), characterized the GMNS surface. The effect of various experimental parameters including pH (5 and 9), flow rate (1, 2, and 3 mL/min) and initial 3,4-DHBA concentration (15, 40 and 60 mg/L) on the transport and adsorption of 3,4-DHBA onto the column were investigated in detail. The obtained result shows that exhaustion time decreased with increasing initial 3,4-DHBA concentration, flow rate and pH. The highest value of adsorbed amount q = 35.66 mg/Kg was obtained from injection of 60 mg/L of initial 3,4-DHBA concentration solution with flow rate}, keywords = {}, pubstate = {published}, tppubtype = {article} } In this paper, a continuous adsorption of 3,4-Dihydroxybenzoic acid (3,4-DHBA) has been studied by using goethite modified natural sand (GMNS) as adsorbent in a fixed-bed column. Scanning electron microscopy coupled with energy-dispersive X-ray analysis, X-ray diffraction and Fourier transform infrared spectroscopy (FTIR), characterized the GMNS surface. The effect of various experimental parameters including pH (5 and 9), flow rate (1, 2, and 3 mL/min) and initial 3,4-DHBA concentration (15, 40 and 60 mg/L) on the transport and adsorption of 3,4-DHBA onto the column were investigated in detail. The obtained result shows that exhaustion time decreased with increasing initial 3,4-DHBA concentration, flow rate and pH. The highest value of adsorbed amount q = 35.66 mg/Kg was obtained from injection of 60 mg/L of initial 3,4-DHBA concentration solution with flow rate |
Marks, Evan A N; Kinigopoulou, Vasiliki; Akrout, Hanene; Azzaz, Ahmed Amine; Doulgeris, Charalampos; Jellali, Salah; Rad, Carlos; Zulueta, Paula Sanchez; Tziritis, Evangelos; El-Bassi, Leila; Ghimbeu, Camelia Matei; Jeguirim, Mejdi Potential for Production of Biochar-Based Fertilizers from Olive Mill Waste in Mediterranean Basin Countries: An Initial Assessment for Spain, Tunisia, and Greece (Article de journal) Sustainability, 12 (15), p. 6081, 2020. @article{Marks2020, title = {Potential for Production of Biochar-Based Fertilizers from Olive Mill Waste in Mediterranean Basin Countries: An Initial Assessment for Spain, Tunisia, and Greece}, author = { Evan A. N. Marks and Vasiliki Kinigopoulou and Hanene Akrout and Ahmed Amine Azzaz and Charalampos Doulgeris and Salah Jellali and Carlos Rad and Paula Sanchez Zulueta and Evangelos Tziritis and Leila El-Bassi and Camelia Matei Ghimbeu and Mejdi Jeguirim}, doi = {10.3390/su12156081}, year = {2020}, date = {2020-08-01}, journal = {Sustainability}, volume = {12}, number = {15}, pages = {6081}, abstract = {Olive mill wastes continue to be a management challenge due to the large volumes produced, particularly due to their toxicity and impacts on the environment. Thermal conversion through pyrolysis or hydrothermal carbonization techniques can detoxify wastes while conserving nutrient contents. In this work, we produced up-to-date data on olive mill waste flows in Spain, Tunisia, and Greece and characterized representative samples in the laboratory. Assays of thermal conversion of olive mill wastewaters and solid wastes were also performed to understand biochar yields and final properties, and the total quantities of nutrients contained were estimated. Of particular note were the quantities of potassium in Tunisian wastewaters, representing 0.6% of the total mass and an annual flow of approximately 5000 t, and in the Spanish solid wastes, an average of 1.7% of the total mass is potassium, representing an annual flow of approximately 23,000 t. Concerning phosphorus, Spanish solid wastes had the highest contents (0.1%), double that of other countries' wastes. Annually, olive mill wastes from the three countries are estimated to contain approximately 35 x 10(3)tons of potassium and 2.6 x 10(3)tons of phosphorus. With this resource converted to biochar, each year more than 700 km(2)of soils could be enriched in 0.2% carbon with biochar at an application rate of 7 t ha(-1).}, keywords = {}, pubstate = {published}, tppubtype = {article} } Olive mill wastes continue to be a management challenge due to the large volumes produced, particularly due to their toxicity and impacts on the environment. Thermal conversion through pyrolysis or hydrothermal carbonization techniques can detoxify wastes while conserving nutrient contents. In this work, we produced up-to-date data on olive mill waste flows in Spain, Tunisia, and Greece and characterized representative samples in the laboratory. Assays of thermal conversion of olive mill wastewaters and solid wastes were also performed to understand biochar yields and final properties, and the total quantities of nutrients contained were estimated. Of particular note were the quantities of potassium in Tunisian wastewaters, representing 0.6% of the total mass and an annual flow of approximately 5000 t, and in the Spanish solid wastes, an average of 1.7% of the total mass is potassium, representing an annual flow of approximately 23,000 t. Concerning phosphorus, Spanish solid wastes had the highest contents (0.1%), double that of other countries' wastes. Annually, olive mill wastes from the three countries are estimated to contain approximately 35 x 10(3)tons of potassium and 2.6 x 10(3)tons of phosphorus. With this resource converted to biochar, each year more than 700 km(2)of soils could be enriched in 0.2% carbon with biochar at an application rate of 7 t ha(-1). |
Anokhin, D V; Grafskaia, K N; Ivanov, D A; Ivan'kova, E M; Marikhin, V A; Myasnikova, L P; Ivanchev, S S Pattern of Monoclinic Phase Distribution in Nascent UHMWPE Particles (Article de journal) Physics of the Solid State, 62 (8), p. 1493–1499, 2020. @article{Anokhin2020, title = {Pattern of Monoclinic Phase Distribution in Nascent UHMWPE Particles}, author = { D. V Anokhin and K. N. Grafskaia and D. A. Ivanov and E. M. Ivan'kova and V. A. Marikhin and L. P. Myasnikova and S. S. Ivanchev}, doi = {10.1134/S1063783420080028}, year = {2020}, date = {2020-08-01}, journal = {Physics of the Solid State}, volume = {62}, number = {8}, pages = {1493--1499}, abstract = {By using the ID13 nanofocus beamline of the European Synchrotron Radiation Facility (Grenoble, France), an X-ray diffraction study of a "virgin" particle of ultra-high molecular weight polyethylene (UHMWPE) taken directly from the powder synthesis products and not subjected to any external mechanical action was carried out. The X-ray diffraction curves obtained by scanning a randomly selected region of the particle 100 x 20 mu m in size with a 0.3 x 0.3 mu m microbeam with a horizontal step of 2 mu m and vertical step of 0.5 mu m exhibited reflexes from the metastable monoclinic phase along with reflections from the orthorhombic phase. It can be supposed that it could be caused by the stresses that developed at specific structure formation during slurry synthesis and were preserved at cooling to room temperature and solvent evaporation. The possibility of the monoclinic phase localization in various morphological formations is discussed.}, keywords = {}, pubstate = {published}, tppubtype = {article} } By using the ID13 nanofocus beamline of the European Synchrotron Radiation Facility (Grenoble, France), an X-ray diffraction study of a "virgin" particle of ultra-high molecular weight polyethylene (UHMWPE) taken directly from the powder synthesis products and not subjected to any external mechanical action was carried out. The X-ray diffraction curves obtained by scanning a randomly selected region of the particle 100 x 20 mu m in size with a 0.3 x 0.3 mu m microbeam with a horizontal step of 2 mu m and vertical step of 0.5 mu m exhibited reflexes from the metastable monoclinic phase along with reflections from the orthorhombic phase. It can be supposed that it could be caused by the stresses that developed at specific structure formation during slurry synthesis and were preserved at cooling to room temperature and solvent evaporation. The possibility of the monoclinic phase localization in various morphological formations is discussed. |
Chor, Ana; Goncalves, Raquel Pires; Costa, Andrea Machado; Farina, Marcos; Ponche, Arnaud; Sirelli, Lys; Schrodj, Gautier; Gree, Simon; de Andrade, Leonardo Rodrigues; Anselme, Karine; Dias, Marcos Lopes In Vitro Degradation of Electrospun Poly(Lactic-Co-Glycolic Acid) (PLGA) for Oral Mucosa Regeneration. (Article de journal) Polymers, 12 (8), 2020. @article{Chor2020, title = {In Vitro Degradation of Electrospun Poly(Lactic-Co-Glycolic Acid) (PLGA) for Oral Mucosa Regeneration.}, author = { Ana Chor and Raquel Pires Goncalves and Andrea Machado Costa and Marcos Farina and Arnaud Ponche and Lys Sirelli and Gautier Schrodj and Simon Gree and Leonardo Rodrigues de Andrade and Karine Anselme and Marcos Lopes Dias}, doi = {10.3390/polym12081853}, year = {2020}, date = {2020-08-01}, journal = {Polymers}, volume = {12}, number = {8}, abstract = {Poly(lactic-co-glycolic acid) (PLGA) has been used in the field of tissue engineering as a scaffold due to its good biocompatibility, biodegradability and mechanical strength. With the aim to explore the degradability of PLGA electrospun nonwoven structures for oral mucosa tissue engineering applications, non-irradiated and gamma irradiated nonwovens were immersed in three different solutions, in which simulated body fluid (SBF) and artificial saliva are important for future oral mucosa tissue engineering. The nonwovens were immersed for 7, 15 and 30 days in SBF, culture media (DMEM) and artificial saliva at 37 °C. Before immersion in the solutions, the dosage of 15 kGy was applied for sterilization in one assay and compared with non-irradiated samples at the same timepoints. Samples were characterized using different techniques such as scanning electron microscopy (SEM), differential scanning calorimetric (DSC) and gel permeation chromatography (GPC) to evaluate the nonwoven degradation and Fourier-transform infrared spectroscopy (FTIR) to evaluate the chain scissions. Our results showed that PLGA nonwovens were constituted by semicrystalline fibers with moderate degradation properties up to thirty days. The non-irradiated samples exhibited slower kinetics of degradation than irradiated nonwovens. For immersion times longer than 7 days in the three different solutions, the mean diameter of irradiated fibers stayed in the same range, but significantly different from the control sample. On non-irradiated samples, the degradation kinetics was slower and the plateau in the diameter value was only attained after 30 days of immersion in the fluids. Plasticization (fluid absorption into the fiber structure) occurred in the bulk material, as confirmed by a decrease in Tg observed by DSC analyses of non-irradiated and irradiated nonwovens, in comparison with the respective controls. In addition, artificial saliva showed a higher capacity of influencing PLGA crystallization than SBF and DMEM. FTIR analyses showed typical PLGA chemical functional groups changes. These results will be important for future application of those PLGA electrospun nonwovens for oral mucosa regeneration.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Poly(lactic-co-glycolic acid) (PLGA) has been used in the field of tissue engineering as a scaffold due to its good biocompatibility, biodegradability and mechanical strength. With the aim to explore the degradability of PLGA electrospun nonwoven structures for oral mucosa tissue engineering applications, non-irradiated and gamma irradiated nonwovens were immersed in three different solutions, in which simulated body fluid (SBF) and artificial saliva are important for future oral mucosa tissue engineering. The nonwovens were immersed for 7, 15 and 30 days in SBF, culture media (DMEM) and artificial saliva at 37 °C. Before immersion in the solutions, the dosage of 15 kGy was applied for sterilization in one assay and compared with non-irradiated samples at the same timepoints. Samples were characterized using different techniques such as scanning electron microscopy (SEM), differential scanning calorimetric (DSC) and gel permeation chromatography (GPC) to evaluate the nonwoven degradation and Fourier-transform infrared spectroscopy (FTIR) to evaluate the chain scissions. Our results showed that PLGA nonwovens were constituted by semicrystalline fibers with moderate degradation properties up to thirty days. The non-irradiated samples exhibited slower kinetics of degradation than irradiated nonwovens. For immersion times longer than 7 days in the three different solutions, the mean diameter of irradiated fibers stayed in the same range, but significantly different from the control sample. On non-irradiated samples, the degradation kinetics was slower and the plateau in the diameter value was only attained after 30 days of immersion in the fluids. Plasticization (fluid absorption into the fiber structure) occurred in the bulk material, as confirmed by a decrease in Tg observed by DSC analyses of non-irradiated and irradiated nonwovens, in comparison with the respective controls. In addition, artificial saliva showed a higher capacity of influencing PLGA crystallization than SBF and DMEM. FTIR analyses showed typical PLGA chemical functional groups changes. These results will be important for future application of those PLGA electrospun nonwovens for oral mucosa regeneration. |
Haddad, Khouloud; Jeguirim, Mejdi; Jellali, Salah; Thevenin, Nicolas; Ruidavets, Lionel; Limousy, Lionel Biochar production from Cypress sawdust and olive mill wastewater: Agronomic approach. (Article de journal) The Science of the total environment, 752 , p. 141713–141713, 2020. @article{Haddad2020, title = {Biochar production from Cypress sawdust and olive mill wastewater: Agronomic approach.}, author = { Khouloud Haddad and Mejdi Jeguirim and Salah Jellali and Nicolas Thevenin and Lionel Ruidavets and Lionel Limousy}, doi = {10.1016/j.scitotenv.2020.141713}, year = {2020}, date = {2020-08-01}, journal = {The Science of the total environment}, volume = {752}, pages = {141713--141713}, abstract = {Olive mill wastewater (OMW) is nowadays considered as a serious source pollution. At the same time, it contains high amounts of nutrients, especially potassium and phosphorus that could be recovered for agricultural purposes. The aim of the current experimental research work is to investigate the agronomic potential use of OMW based biochar produced from the slow pyrolysis at 500°C of raw cypress sawdust (CS) impregnated with OMW (ICS-OMW-B). In order to understand the contribution of OMW, two additional biochars were produced from raw cypress sawdust (RCS-B) and cypress sawdust pretreated with potassium chloride (ICS-K-B). Results indicated that RCS impregnation by OMW significantly improved the produced biochar's chemical properties, especially its nutrients contents. Furthermore, in comparison with the other biochars, ICS-OMW-B application as an organic fertilizer showed promising results in terms of produced fresh and dry masses, as well as potassium bioavailability as assessed in test experiments with ryegrass. For instance, the dry matter masses of the rye-grass treated with ICS-OMW-B were about 23, 34 and 50wt% higher than the ones measured for the tests using RCS-B, ICS-K-B and synthetic K-fertilizer as amendments, respectively. Besides, this biochar has a potential effect on the suppression of various pathogens existing in the tested agricultural soil. All these results demonstrated that the biochar generated from the slow pyrolysis of impregnated sawdust with OMW could be considered as attractive and promising organic fertilizer for acidic agricultural soils.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Olive mill wastewater (OMW) is nowadays considered as a serious source pollution. At the same time, it contains high amounts of nutrients, especially potassium and phosphorus that could be recovered for agricultural purposes. The aim of the current experimental research work is to investigate the agronomic potential use of OMW based biochar produced from the slow pyrolysis at 500°C of raw cypress sawdust (CS) impregnated with OMW (ICS-OMW-B). In order to understand the contribution of OMW, two additional biochars were produced from raw cypress sawdust (RCS-B) and cypress sawdust pretreated with potassium chloride (ICS-K-B). Results indicated that RCS impregnation by OMW significantly improved the produced biochar's chemical properties, especially its nutrients contents. Furthermore, in comparison with the other biochars, ICS-OMW-B application as an organic fertilizer showed promising results in terms of produced fresh and dry masses, as well as potassium bioavailability as assessed in test experiments with ryegrass. For instance, the dry matter masses of the rye-grass treated with ICS-OMW-B were about 23, 34 and 50wt% higher than the ones measured for the tests using RCS-B, ICS-K-B and synthetic K-fertilizer as amendments, respectively. Besides, this biochar has a potential effect on the suppression of various pathogens existing in the tested agricultural soil. All these results demonstrated that the biochar generated from the slow pyrolysis of impregnated sawdust with OMW could be considered as attractive and promising organic fertilizer for acidic agricultural soils. |
Garra, Patxi; Fouassier, Jean Pierre; Lakhdar, Sami; Yagci, Yusuf; Lalevee, Jacques Visible light photoinitiating systems by charge transfer complexes: Photochemistry without dyes (Article de journal) Progress in Polymer Science, 107 , p. 101277, 2020. @article{Garra2020, title = {Visible light photoinitiating systems by charge transfer complexes: Photochemistry without dyes}, author = { Patxi Garra and Jean Pierre Fouassier and Sami Lakhdar and Yusuf Yagci and Jacques Lalevee}, doi = {10.1016/j.progpolymsci.2020.101277}, year = {2020}, date = {2020-08-01}, journal = {Progress in Polymer Science}, volume = {107}, pages = {101277}, abstract = {Visible light induced synthesis generally involves i) dyes or chromophores with potential photocleavable bonds (Type I photoinitiator), ii) hydrogen abstractions (Type II photoinitiator) by dyes/chromphores and iii) photoredox catalysis using metal-based or metal-free dyes. Beyond these strategies, charge transfer complexes (CTCs), also referred to as electron donor acceptor (EDA) complexes, were also reported to be the visible light initiating species. In these cases, the ground state intimate association of a donor and acceptor creates a new structure that can result in (bathochromic) visible light absorption compared to the separated compounds. In the present review, an update on CTCs as photoinitiating systems for photopoly-merization applications will be provided with examples of CTC-specific structure/reactivity/efficiency relationships. Interestingly, CTC can act as dual photo/thermal photoinitiators both in cationic and free radical photopolymerizations. Also, low optical density of the CTC in resins allowed to access extremely thick samples and composites. The possibility of extending wavelength sensitivity of photopolymerizations by excited state complexes (exciplexes) is also discussed. (C) 2020 Elsevier B.V. All rights reserved.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Visible light induced synthesis generally involves i) dyes or chromophores with potential photocleavable bonds (Type I photoinitiator), ii) hydrogen abstractions (Type II photoinitiator) by dyes/chromphores and iii) photoredox catalysis using metal-based or metal-free dyes. Beyond these strategies, charge transfer complexes (CTCs), also referred to as electron donor acceptor (EDA) complexes, were also reported to be the visible light initiating species. In these cases, the ground state intimate association of a donor and acceptor creates a new structure that can result in (bathochromic) visible light absorption compared to the separated compounds. In the present review, an update on CTCs as photoinitiating systems for photopoly-merization applications will be provided with examples of CTC-specific structure/reactivity/efficiency relationships. Interestingly, CTC can act as dual photo/thermal photoinitiators both in cationic and free radical photopolymerizations. Also, low optical density of the CTC in resins allowed to access extremely thick samples and composites. The possibility of extending wavelength sensitivity of photopolymerizations by excited state complexes (exciplexes) is also discussed. (C) 2020 Elsevier B.V. All rights reserved. |
Narayanan, Lakshmi Kanthan; Sankaranarayanan, Suresh; Rodrigues, Joel J P C; Lorenz, Pascal Multi-Agent-Based Modeling for Underground Pipe Health and Water Quality Monitoring for Supplying Quality Water (Article de journal) International Journal of Intelligent Information Technologies, 16 (3), p. 52–79, 2020. @article{Narayanan2020, title = {Multi-Agent-Based Modeling for Underground Pipe Health and Water Quality Monitoring for Supplying Quality Water}, author = { Lakshmi Kanthan Narayanan and Suresh Sankaranarayanan and Joel J. P. C. Rodrigues and Pascal Lorenz}, doi = {10.4018/IJIIT.2020070103}, year = {2020}, date = {2020-07-01}, journal = {International Journal of Intelligent Information Technologies}, volume = {16}, number = {3}, pages = {52--79}, abstract = {This article discusses distributed monitoring through the deployment of various multiagents in the IoT-Fog-based water distribution network (WDN). This will ensure the right amount of water supplied with respect to demand forecasted to residents. In addition, underground pipe health is also monitored by means of a multiagent based on hydraulic parameters supplying water forecasted with minimal losses which would minimize the operational and material cost involved in recovery or repair. Lastly, there are agents deployed towards leakage monitoring and anti-theft detection of water. The multiagents act upon various parameters of hydrology and analysis is based on the data acquired by the various sensors deployed in the water distribution network which perform partial automation of the disconnection of the supply during extreme critical conditions.}, keywords = {}, pubstate = {published}, tppubtype = {article} } This article discusses distributed monitoring through the deployment of various multiagents in the IoT-Fog-based water distribution network (WDN). This will ensure the right amount of water supplied with respect to demand forecasted to residents. In addition, underground pipe health is also monitored by means of a multiagent based on hydraulic parameters supplying water forecasted with minimal losses which would minimize the operational and material cost involved in recovery or repair. Lastly, there are agents deployed towards leakage monitoring and anti-theft detection of water. The multiagents act upon various parameters of hydrology and analysis is based on the data acquired by the various sensors deployed in the water distribution network which perform partial automation of the disconnection of the supply during extreme critical conditions. |
del Rios, Carolina Mar Saavedra; Simonin, Loic; de Geyer, Arnaud; Ghimbeu, Camelia Matei; Dupont, Capucine Unraveling the Properties of Biomass-Derived Hard Carbons upon Thermal Treatment for a Practical Application in Na-Ion Batteries (Article de journal) Energies, 13 (14), p. 3513, 2020. @article{Rios2020, title = {Unraveling the Properties of Biomass-Derived Hard Carbons upon Thermal Treatment for a Practical Application in Na-Ion Batteries}, author = { Carolina del Mar Saavedra Rios and Loic Simonin and Arnaud de Geyer and Camelia Matei Ghimbeu and Capucine Dupont}, doi = {10.3390/en13143513}, year = {2020}, date = {2020-07-01}, journal = {Energies}, volume = {13}, number = {14}, pages = {3513}, abstract = {Biomass is gaining increased attention as a sustainable and low-cost hard carbon (HC) precursor. However, biomass properties are often unexplored and unrelated to HC performance. Herein, we used pine, beechwood, miscanthus, and wheat straw precursors to synthesize HCs at 1000 degrees C, 1200 degrees C and 1400 degrees C by a two-steps pyrolysis treatment. The final physicochemical and electrochemical properties of the HC evidenced dissimilar trends, mainly influenced by the precursor's inorganic content, and less by the thermal treatment. Pine and beechwood HCs delivered the highest reversible capacity and coulombic efficiency (CE) at 1400 degrees C of about 300 mAh center dot g(-1)and 80%, respectively. This performance can be attributed to the structure derived from the high carbon purity precursors. Miscanthus and wheat straw HC performance was strongly affected by the silicon, potassium, and calcium content in the biomasses, which promoted simultaneous detrimental phenomena of intrinsic activation, formation of a silicon carbide phase, and growth of graphitic domains with temperature. The latter HCs delivered 240-200 mAh center dot g(-1)of reversible capacity and 70-60% of CE, respectively, at 1400 degrees C. The biomass precursor composition, especially its inorganic fraction, seems to be a key parameter to control, for obtaining high performance hard carbon electrodes by direct pyrolysis process.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Biomass is gaining increased attention as a sustainable and low-cost hard carbon (HC) precursor. However, biomass properties are often unexplored and unrelated to HC performance. Herein, we used pine, beechwood, miscanthus, and wheat straw precursors to synthesize HCs at 1000 degrees C, 1200 degrees C and 1400 degrees C by a two-steps pyrolysis treatment. The final physicochemical and electrochemical properties of the HC evidenced dissimilar trends, mainly influenced by the precursor's inorganic content, and less by the thermal treatment. Pine and beechwood HCs delivered the highest reversible capacity and coulombic efficiency (CE) at 1400 degrees C of about 300 mAh center dot g(-1)and 80%, respectively. This performance can be attributed to the structure derived from the high carbon purity precursors. Miscanthus and wheat straw HC performance was strongly affected by the silicon, potassium, and calcium content in the biomasses, which promoted simultaneous detrimental phenomena of intrinsic activation, formation of a silicon carbide phase, and growth of graphitic domains with temperature. The latter HCs delivered 240-200 mAh center dot g(-1)of reversible capacity and 70-60% of CE, respectively, at 1400 degrees C. The biomass precursor composition, especially its inorganic fraction, seems to be a key parameter to control, for obtaining high performance hard carbon electrodes by direct pyrolysis process. |
Sprick, Elodie; Graff, Bernadette; Becht, Jean-Michel; Tigges, Thomas; Neuhaus, Kira; Weber, Christoph; Lalevee, Jacques New bio-sourced hydrogen donors as high performance coinitiators and additives for CQ-based systems: Toward aromatic amine-free photoinitiating systems (Article de journal) European Polymer Journal, 134 , p. 109794, 2020. @article{Sprick2020a, title = {New bio-sourced hydrogen donors as high performance coinitiators and additives for CQ-based systems: Toward aromatic amine-free photoinitiating systems}, author = { Elodie Sprick and Bernadette Graff and Jean-Michel Becht and Thomas Tigges and Kira Neuhaus and Christoph Weber and Jacques Lalevee}, doi = {10.1016/j.eurpolymj.2020.109794}, year = {2020}, date = {2020-07-01}, journal = {European Polymer Journal}, volume = {134}, pages = {109794}, abstract = {Two new hydrogen-donors synthesized from natural products (curcumin and 4-methylumbelliferone) are proposed here as new classes of high performance bio-sourced coinitiators (BHD) for the polymerization of methacrylates under blue light irradiation. In presence of these naturally derived compounds good polymerization performances are reached and good bleaching properties are obtained compared to traditionally used camphorquinone (CQ)-based systems.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Two new hydrogen-donors synthesized from natural products (curcumin and 4-methylumbelliferone) are proposed here as new classes of high performance bio-sourced coinitiators (BHD) for the polymerization of methacrylates under blue light irradiation. In presence of these naturally derived compounds good polymerization performances are reached and good bleaching properties are obtained compared to traditionally used camphorquinone (CQ)-based systems. |
Abdallah, Mira; Hijazi, Akram; Graff, Bernadette; Fouassier, Jean-Pierre; Dumur, Frederic; Lalevee, Jacques In Silico Design of Nitrocoumarins as Near-UV Photoinitiators: Toward Interesting Opportunities in Composites and 3D Printing Technologies (Article de journal) Acs Applied Polymer Materials, 2 (7), p. 2890–2901, 2020. @article{Abdallah2020c, title = {In Silico Design of Nitrocoumarins as Near-UV Photoinitiators: Toward Interesting Opportunities in Composites and 3D Printing Technologies}, author = { Mira Abdallah and Akram Hijazi and Bernadette Graff and Jean-Pierre Fouassier and Frederic Dumur and Jacques Lalevee}, doi = {10.1021/acsapm.0c00409}, year = {2020}, date = {2020-07-01}, journal = {Acs Applied Polymer Materials}, volume = {2}, number = {7}, pages = {2890--2901}, abstract = {In this research, 31 nitrocoumarins (including 27 structures never reported in the literature) were designed through molecular orbital calculations and synthesized as high-performance near-UV-visible light photoinitiators of polymerization for a better understanding of their structure/reactivity/efficiency relationship. Based on their photoinitiating abilities examined during the free-radical polymerization (FRP) of acrylates, different coumarins examined in this work can be classified into three main categories: (1) very reactive ones (Coum6,7,11,12 & 26); (2) moderately reactive nitrocoumarins (Coum1,2,16,20,21,23,25,27 & 28); and (3) nitrocoumarins of low reactivity (Coum3,4,5,8,9,10,13,14,15,17,18,19,22,24,29,30&31). Different techniques were used in order to understand their photoinitiating abilities as well as the associated chemical mechanisms. The real-time Fourier transform infrared technique has been used to follow the polymerization profiles (reactive function conversion (FCs) vs irradiation time). Different two- and three-component photoinitiating systems based on nitrocoumarin/iodonium salt (or N-phenylglycine (NPG) or ethyl 4-(dimethylamino)benzoate) and nitrocoumarin/iodonium salt/NPG were examined for the FRP of acrylates or/and the cationic polymerization of epoxides upon irradiation with a light-emitting diode at 405 nm as an unharmed and inexpensive irradiation source. Moreover, cyclic voltammetry, fluorescence spectroscopy, UV-visible spectroscopy, and electron spin resonance techniques were also used to provide a full picture of the involved chemical mechanisms. Excellent polymerization performances (i.e., high final reactive FCs and also great rates of polymerization (R-p) were obtained using these derivatives. Some applications in three-dimensional printing and composite synthesis are reported to highlight the interest of the proposed structures in modern technologies.}, keywords = {}, pubstate = {published}, tppubtype = {article} } In this research, 31 nitrocoumarins (including 27 structures never reported in the literature) were designed through molecular orbital calculations and synthesized as high-performance near-UV-visible light photoinitiators of polymerization for a better understanding of their structure/reactivity/efficiency relationship. Based on their photoinitiating abilities examined during the free-radical polymerization (FRP) of acrylates, different coumarins examined in this work can be classified into three main categories: (1) very reactive ones (Coum6,7,11,12 & 26); (2) moderately reactive nitrocoumarins (Coum1,2,16,20,21,23,25,27 & 28); and (3) nitrocoumarins of low reactivity (Coum3,4,5,8,9,10,13,14,15,17,18,19,22,24,29,30&31). Different techniques were used in order to understand their photoinitiating abilities as well as the associated chemical mechanisms. The real-time Fourier transform infrared technique has been used to follow the polymerization profiles (reactive function conversion (FCs) vs irradiation time). Different two- and three-component photoinitiating systems based on nitrocoumarin/iodonium salt (or N-phenylglycine (NPG) or ethyl 4-(dimethylamino)benzoate) and nitrocoumarin/iodonium salt/NPG were examined for the FRP of acrylates or/and the cationic polymerization of epoxides upon irradiation with a light-emitting diode at 405 nm as an unharmed and inexpensive irradiation source. Moreover, cyclic voltammetry, fluorescence spectroscopy, UV-visible spectroscopy, and electron spin resonance techniques were also used to provide a full picture of the involved chemical mechanisms. Excellent polymerization performances (i.e., high final reactive FCs and also great rates of polymerization (R-p) were obtained using these derivatives. Some applications in three-dimensional printing and composite synthesis are reported to highlight the interest of the proposed structures in modern technologies. |
Abdallah, Mira; Hijazi, Akram; Lin, Jui-Teng; Graff, Bernadette; Dumur, Frederic; Lalevee, Jacques Coumarin Derivatives as Photoinitiators in Photo-Oxidation and Photo-Reduction Processes and a Kinetic Model for Simulations of the Associated Polymerization Profiles (Article de journal) Acs Applied Polymer Materials, 2 (7), p. 2769–2780, 2020. @article{Abdallah2020b, title = {Coumarin Derivatives as Photoinitiators in Photo-Oxidation and Photo-Reduction Processes and a Kinetic Model for Simulations of the Associated Polymerization Profiles}, author = { Mira Abdallah and Akram Hijazi and Jui-Teng Lin and Bernadette Graff and Frederic Dumur and Jacques Lalevee}, doi = {10.1021/acsapm.0c00340}, year = {2020}, date = {2020-07-01}, journal = {Acs Applied Polymer Materials}, volume = {2}, number = {7}, pages = {2769--2780}, abstract = {In this work, the design of an original series of coumarin derivatives CoumC1-CoumC13) is presented. Chemical structures of these coumarins were selected by molecular modeling to ensure both excellent light absorption properties and high potential photoreactivity (high excited-state energy). As a striking result of this in silico design, eight of the 13 proposed coumarins were never presented and were specifically proposed for this work, indicating the interest in their structures. New multicomponent photoinitiating systems (PISs) based on these coumarins are proposed for the free radical polymerization (FRP) of (meth)acrylates and examined upon visible light irradiation using a light-emitting diode (LED) as a safe and economical irradiation source. The proposed systems are based on coumarins that act as remarkable photoinitiators/photosensitizers (PIs/PSs) combined with N-phenyl-glycine (NPG) and/or iodonium salt (Iod) as co-initiators to generate the reactive species (radicals) that will initiate the photopolymerization reaction. Investigations of the chemical mechanisms suggested by the different interactions that take place as well as the photophysical and photochemical properties of coumarins are provided. It is possible to obtain high polymerization rates (R-p), excellent photoinitiating abilities, and great reactive function conversions (FC) with these structures based on the coumarin core. Coumarins show high efficiency for the FRP of (meth)acrylates by reaction with iodonium salt (a photo-oxidation process) or with amine (a photo-reduction process). These compounds were used in three-dimensional (3D) printing resins but also for the preparation of photocomposites. In this latter case, excellent depth of cure was noted as remarkable behavior. To rationalize the experimental results, a kinetic model for a three-component system has been established to analyze the role of oxygen in the monomer conversions and the conversion enhancement observed while using an amine as a co-initiator.}, keywords = {}, pubstate = {published}, tppubtype = {article} } In this work, the design of an original series of coumarin derivatives CoumC1-CoumC13) is presented. Chemical structures of these coumarins were selected by molecular modeling to ensure both excellent light absorption properties and high potential photoreactivity (high excited-state energy). As a striking result of this in silico design, eight of the 13 proposed coumarins were never presented and were specifically proposed for this work, indicating the interest in their structures. New multicomponent photoinitiating systems (PISs) based on these coumarins are proposed for the free radical polymerization (FRP) of (meth)acrylates and examined upon visible light irradiation using a light-emitting diode (LED) as a safe and economical irradiation source. The proposed systems are based on coumarins that act as remarkable photoinitiators/photosensitizers (PIs/PSs) combined with N-phenyl-glycine (NPG) and/or iodonium salt (Iod) as co-initiators to generate the reactive species (radicals) that will initiate the photopolymerization reaction. Investigations of the chemical mechanisms suggested by the different interactions that take place as well as the photophysical and photochemical properties of coumarins are provided. It is possible to obtain high polymerization rates (R-p), excellent photoinitiating abilities, and great reactive function conversions (FC) with these structures based on the coumarin core. Coumarins show high efficiency for the FRP of (meth)acrylates by reaction with iodonium salt (a photo-oxidation process) or with amine (a photo-reduction process). These compounds were used in three-dimensional (3D) printing resins but also for the preparation of photocomposites. In this latter case, excellent depth of cure was noted as remarkable behavior. To rationalize the experimental results, a kinetic model for a three-component system has been established to analyze the role of oxygen in the monomer conversions and the conversion enhancement observed while using an amine as a co-initiator. |
Lebeau, Benedicte; Naboulsi, Issam; Michelin, Laure; Marichal, Claire; Rigolet, Severinne; Carteret, Cedric; Brunet, Sylvette; Bonne, Magali; Blin, Jean-Luc Amorphous mesostructured zirconia with high (hydro)thermal stability (Article de journal) Rsc Advances, 10 (44), p. 26165–26176, 2020. @article{Lebeau2020, title = {Amorphous mesostructured zirconia with high (hydro)thermal stability}, author = { Benedicte Lebeau and Issam Naboulsi and Laure Michelin and Claire Marichal and Severinne Rigolet and Cedric Carteret and Sylvette Brunet and Magali Bonne and Jean-Luc Blin}, doi = {10.1039/d0ra04824k}, year = {2020}, date = {2020-07-01}, journal = {Rsc Advances}, volume = {10}, number = {44}, pages = {26165--26176}, abstract = {Here, combining the evaporation-induced self-assembly (EISA) method and the liquid crystal templating pathway, mesostructured amorphous zirconium oxides have been prepared by a soft templating method without addition of any heteroelement to stabilize the mesopore framework. The recovered materials have been characterized by SAXS measurements, nitrogen adsorption-desorption analysis and X-ray diffraction (XRD). The obtained mesostructured zirconia exhibits a high thermal stability. Anin situXRD study performed as a function of temperature shows that the amorphous ZrO2, obtained after removal of the pore templating agent (pluronic P123), begins to crystallize in air from 420 degrees C. Amorphous mesostructured ZrO(2)also presents a high hydrothermal stability; these materials are not degraded after 72 hours in boiling water.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Here, combining the evaporation-induced self-assembly (EISA) method and the liquid crystal templating pathway, mesostructured amorphous zirconium oxides have been prepared by a soft templating method without addition of any heteroelement to stabilize the mesopore framework. The recovered materials have been characterized by SAXS measurements, nitrogen adsorption-desorption analysis and X-ray diffraction (XRD). The obtained mesostructured zirconia exhibits a high thermal stability. Anin situXRD study performed as a function of temperature shows that the amorphous ZrO2, obtained after removal of the pore templating agent (pluronic P123), begins to crystallize in air from 420 degrees C. Amorphous mesostructured ZrO(2)also presents a high hydrothermal stability; these materials are not degraded after 72 hours in boiling water. |
Litvinov, Victor; Deblieck, Rudy; Clair, Charles; den Fonteyne, Winke Van; Lallam, Abdelaziz; Kleppinger, Ralf; Ivanov, Dimitri A; Ries, Michael E; Boerakker, Mark Molecular Structure, Phase Composition, Melting Behavior, and Chain Entanglements in the Amorphous Phase of High-Density Polyethylenes (Article de journal) Macromolecules, 53 (13), p. 5418–5433, 2020. @article{Litvinov2020, title = {Molecular Structure, Phase Composition, Melting Behavior, and Chain Entanglements in the Amorphous Phase of High-Density Polyethylenes}, author = { Victor Litvinov and Rudy Deblieck and Charles Clair and Winke Van den Fonteyne and Abdelaziz Lallam and Ralf Kleppinger and Dimitri A. Ivanov and Michael E. Ries and Mark Boerakker}, doi = {10.1021/acs.macromol.0c00956}, year = {2020}, date = {2020-07-01}, journal = {Macromolecules}, volume = {53}, number = {13}, pages = {5418--5433}, abstract = {A methodology for estimating the entanglement density in the amorphous phase of semicrystalline polyolefins was developed. The method is based on the analysis of the density of physical network junctions in the amorphous phase by H-1 NMR T-2 relaxation experiments. The density of the entanglement network was estimated for melt- and high-pressure-crystallized high-density polyethylenes (HDPEs) at temperatures close to and gradually approaching melting. Its value is lower for high-pressure-crystallized HDPE than for the same melt-crystallized polymer. The network of entanglements is characterized by the fraction of entangled network chains, the weight-average molecular weight of the network chains between apparent chain entanglements, M-e, and the volume average density of apparent chain entanglements. The entanglement network was studied in a series of low- and high-molecular-weight HDPEs and bimodal HDPE samples with different molecular weight characteristics and densities controlled by different contents of the 1-butene comonomer. It turns out that the molecular weight characteristics of the HDPEs influence the entanglement network. The fraction of network chains and the average density of apparent chain entanglements decrease with decreasing molecular weight M-n due to the "dilution" effect caused by disentangled chain-end segments increasing the M-e. The current methodology is of interest for studying the effect of crystallization conditions, molecular structures, and short-chain branches on phase composition, melting behavior, and chain entanglements in the amorphous phase of polyolefins. The method allows estimation of the fraction of network chains, which potentially can form tie-chain segments during deformation. The effect of short-chain branches and molecular weight characteristics on the creep response of polyolefins is discussed.}, keywords = {}, pubstate = {published}, tppubtype = {article} } A methodology for estimating the entanglement density in the amorphous phase of semicrystalline polyolefins was developed. The method is based on the analysis of the density of physical network junctions in the amorphous phase by H-1 NMR T-2 relaxation experiments. The density of the entanglement network was estimated for melt- and high-pressure-crystallized high-density polyethylenes (HDPEs) at temperatures close to and gradually approaching melting. Its value is lower for high-pressure-crystallized HDPE than for the same melt-crystallized polymer. The network of entanglements is characterized by the fraction of entangled network chains, the weight-average molecular weight of the network chains between apparent chain entanglements, M-e, and the volume average density of apparent chain entanglements. The entanglement network was studied in a series of low- and high-molecular-weight HDPEs and bimodal HDPE samples with different molecular weight characteristics and densities controlled by different contents of the 1-butene comonomer. It turns out that the molecular weight characteristics of the HDPEs influence the entanglement network. The fraction of network chains and the average density of apparent chain entanglements decrease with decreasing molecular weight M-n due to the "dilution" effect caused by disentangled chain-end segments increasing the M-e. The current methodology is of interest for studying the effect of crystallization conditions, molecular structures, and short-chain branches on phase composition, melting behavior, and chain entanglements in the amorphous phase of polyolefins. The method allows estimation of the fraction of network chains, which potentially can form tie-chain segments during deformation. The effect of short-chain branches and molecular weight characteristics on the creep response of polyolefins is discussed. |
Diboune, Mathieu; Nouali, Habiba; Soulard, Michel; Patarin, Joel; Rioland, Guillaume; Faye, Delphine; Daou, Jean T Efficient Removal of Volatile Organic Compounds by FAU-Type Zeolite Coatings. (Article de journal) Molecules (Basel, Switzerland), 25 (15), 2020. @article{Diboune2020, title = {Efficient Removal of Volatile Organic Compounds by FAU-Type Zeolite Coatings.}, author = { Mathieu Diboune and Habiba Nouali and Michel Soulard and Joel Patarin and Guillaume Rioland and Delphine Faye and T. Jean Daou}, doi = {10.3390/molecules25153336}, year = {2020}, date = {2020-07-01}, journal = {Molecules (Basel, Switzerland)}, volume = {25}, number = {15}, abstract = {Silicone and pure organic binders were used to develop FAU-type zeolite coatings applied on pre-treated aluminum substrates by using a spraying method and then cured under specific conditions. The influence of the amount of binder on adhesion properties of zeolite coatings was first investigated to determine the optimum ratio between zeolite and binder. Zeolite coatings were then elaborated with a high zeolite content (between 70 and 80 wt.%) to ensure high adsorption capacities. The amount of binders involved in different zeolite coatings was sufficient to achieve interesting adhesion and cohesion properties. The accessibility of zeolite microporosity was studied by nitrogen adsorption-desorption measurements, which revealed a very small or no loss of the micropore volume for the optimized coatings. Volatile Organic Compounds (VOCs) adsorption measurements were carried out using n-hexane as probe molecule. FAU-type zeolite in powder form adsorbs 180 mg/ganhydrous zeolite, whereas the amounts of n-hexane adsorbed by zeolite coatings ranged from 131 to 175 mg/ganhydrous zeolite.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Silicone and pure organic binders were used to develop FAU-type zeolite coatings applied on pre-treated aluminum substrates by using a spraying method and then cured under specific conditions. The influence of the amount of binder on adhesion properties of zeolite coatings was first investigated to determine the optimum ratio between zeolite and binder. Zeolite coatings were then elaborated with a high zeolite content (between 70 and 80 wt.%) to ensure high adsorption capacities. The amount of binders involved in different zeolite coatings was sufficient to achieve interesting adhesion and cohesion properties. The accessibility of zeolite microporosity was studied by nitrogen adsorption-desorption measurements, which revealed a very small or no loss of the micropore volume for the optimized coatings. Volatile Organic Compounds (VOCs) adsorption measurements were carried out using n-hexane as probe molecule. FAU-type zeolite in powder form adsorbs 180 mg/ganhydrous zeolite, whereas the amounts of n-hexane adsorbed by zeolite coatings ranged from 131 to 175 mg/ganhydrous zeolite. |
Caillosse, Etienne; Zaier, Mohamed; Mezghani, Mariam; Hajjar-Garreau, Samar; Vidal, Loic; Lougnot, Daniel; Balan, Lavinia Photo-Induced Self-Assembly of Silver Nanoparticles for Rapid Generation of First and Second Surface Mirrors (Article de journal) Acs Applied Nano Materials, 3 (7), p. 6531–6540, 2020. @article{Caillosse2020, title = {Photo-Induced Self-Assembly of Silver Nanoparticles for Rapid Generation of First and Second Surface Mirrors}, author = { Etienne Caillosse and Mohamed Zaier and Mariam Mezghani and Samar Hajjar-Garreau and Loic Vidal and Daniel Lougnot and Lavinia Balan}, doi = {10.1021/acsanm.0c01010}, year = {2020}, date = {2020-07-01}, journal = {Acs Applied Nano Materials}, volume = {3}, number = {7}, pages = {6531--6540}, abstract = {Interesting mirror-like, highly reflective, and conductive silver films have been successfully generated directly on a glass slide using a simple and fast photoinduced approach. A water-based photosensitive formulation containing the silver precursor and a photogenerator of free radicals was used. It was applied like paint and exposed to UV light for a few seconds, in the absence of any additional reducing agents and without further treatment of any kind. This approach allowed ultrathin films of silver nanoparticles to be generated in situ (AgNPs) on the back side of the glass substrate. The particles are homogeneously autoassembled onto the glass surface and the glass/silver diopter exhibits a high reflective character. With such an experimental arrangement, reflective surfaces are obtained: in contact with the glass slide, which is called the second surface mirror, and on the air side, which is called the first surface mirror. Quite interestingly, these reflective and conductive thin films exhibit strong natural adhesion on the glass substrate without the need for enhancing treatments (sensitization or activation) to improve the adhesion of the silver layer to the glass, as usual with silver glass mirrors. The influence of several chemical and photonic parameters has been examined in order to optimize the final optical and electrical properties of these silver films.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Interesting mirror-like, highly reflective, and conductive silver films have been successfully generated directly on a glass slide using a simple and fast photoinduced approach. A water-based photosensitive formulation containing the silver precursor and a photogenerator of free radicals was used. It was applied like paint and exposed to UV light for a few seconds, in the absence of any additional reducing agents and without further treatment of any kind. This approach allowed ultrathin films of silver nanoparticles to be generated in situ (AgNPs) on the back side of the glass substrate. The particles are homogeneously autoassembled onto the glass surface and the glass/silver diopter exhibits a high reflective character. With such an experimental arrangement, reflective surfaces are obtained: in contact with the glass slide, which is called the second surface mirror, and on the air side, which is called the first surface mirror. Quite interestingly, these reflective and conductive thin films exhibit strong natural adhesion on the glass substrate without the need for enhancing treatments (sensitization or activation) to improve the adhesion of the silver layer to the glass, as usual with silver glass mirrors. The influence of several chemical and photonic parameters has been examined in order to optimize the final optical and electrical properties of these silver films. |
Tkachenko, Vitalii; Vidal, Loic; Josien, Ludovic; Schmutz, Marc; Poly, Julien; Chemtob, Abraham Characterizing the Core-Shell Architecture of Block Copolymer Nanoparticles with Electron Microscopy: A Multi-Technique Approach. (Article de journal) Polymers, 12 (8), 2020. @article{Tkachenko2020b, title = {Characterizing the Core-Shell Architecture of Block Copolymer Nanoparticles with Electron Microscopy: A Multi-Technique Approach.}, author = { Vitalii Tkachenko and Loic Vidal and Ludovic Josien and Marc Schmutz and Julien Poly and Abraham Chemtob}, doi = {10.3390/polym12081656}, year = {2020}, date = {2020-07-01}, journal = {Polymers}, volume = {12}, number = {8}, abstract = {Electron microscopy has proved to be a major tool to study the structure of self-assembled amphiphilic block copolymer particles. These specimens, like supramolecular biological structures, are problematic for electron microscopy because of their poor capacity to scatter electrons and their susceptibility to radiation damage and dehydration. Sub-50 nm core-shell spherical particles made up of poly(hydroxyethyl acrylate)-b-poly(styrene) are prepared via polymerization-induced self-assembly (PISA). For their morphological characterization, we discuss the advantages, limitations, and artefacts of TEM with or without staining, cryo-TEM, and SEM. A number of technical points are addressed such as precisely shaping of particle boundaries, resolving the particle shell, differentiating particle core and shell, and the effect of sample drying and staining. TEM without staining and cryo-TEM largely evaluate the core diameter. Negative staining TEM is more efficient than positive staining TEM to preserve native structure and to visualize the entire particle volume. However, no technique allows for a satisfactory imaging of both core and shell regions. The presence of long protruding chains is manifested by patched structure in cryo-TEM and a significant edge effect in SEM. This manuscript provides a basis for polymer chemists to develop their own specimen preparations and to tackle the interpretation of challenging systems.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Electron microscopy has proved to be a major tool to study the structure of self-assembled amphiphilic block copolymer particles. These specimens, like supramolecular biological structures, are problematic for electron microscopy because of their poor capacity to scatter electrons and their susceptibility to radiation damage and dehydration. Sub-50 nm core-shell spherical particles made up of poly(hydroxyethyl acrylate)-b-poly(styrene) are prepared via polymerization-induced self-assembly (PISA). For their morphological characterization, we discuss the advantages, limitations, and artefacts of TEM with or without staining, cryo-TEM, and SEM. A number of technical points are addressed such as precisely shaping of particle boundaries, resolving the particle shell, differentiating particle core and shell, and the effect of sample drying and staining. TEM without staining and cryo-TEM largely evaluate the core diameter. Negative staining TEM is more efficient than positive staining TEM to preserve native structure and to visualize the entire particle volume. However, no technique allows for a satisfactory imaging of both core and shell regions. The presence of long protruding chains is manifested by patched structure in cryo-TEM and a significant edge effect in SEM. This manuscript provides a basis for polymer chemists to develop their own specimen preparations and to tackle the interpretation of challenging systems. |
Chen, Hong; Noirbent, Guillaume; Sun, Ke; Brunel, Damien; Gigmes, Didier; Morlet-Savary, Fabrice; Zhang, Yijun; Liu, Shaohui; Xiao, Pu; Dumur, Frederic; Lalevee, Jacques Photoinitiators derived from natural product scaffolds: monochalcones in three-component photoinitiating systems and their applications in 3D printing (Article de journal) Polymer Chemistry, 11 (28), p. 4647–4659, 2020. @article{Chen2020, title = {Photoinitiators derived from natural product scaffolds: monochalcones in three-component photoinitiating systems and their applications in 3D printing}, author = { Hong Chen and Guillaume Noirbent and Ke Sun and Damien Brunel and Didier Gigmes and Fabrice Morlet-Savary and Yijun Zhang and Shaohui Liu and Pu Xiao and Frederic Dumur and Jacques Lalevee}, doi = {10.1039/d0py00568a}, year = {2020}, date = {2020-07-01}, journal = {Polymer Chemistry}, volume = {11}, number = {28}, pages = {4647--4659}, abstract = {The design and development of high-performance photoinitiating systems applicable to visible light delivered from light-emitting diodes (LEDs) attract ever-increasing attention due to their great potential applications in various fields. Chalcones belong to a well-established class of natural compounds present in many plants. In this context, photoinitiators based on the scaffolds of natural compounds have probably great potential to open the way for non-toxic photoinitiators in the manufacturing of biocompatible polymer materials. In this work, 23 different chalcones selected fromin silicomolecular design (i.e.through molecular orbital calculations) were used in conjunction with an aminei.e.ethyl 4-(dimethylamino) benzoate (EDB) and an iodonium salt (bis-(4-tert-butylphenyl)iodonium hexafluorophosphate, Iod) to form photoinitiating systems (PISs) capable of initiating the polymerization of polyethylene glycol (600) diacrylate (PEG-diacrylate)viaan oxidation-reduction reaction mechanism. The formation of hydrogels by the photopolymerization of PEG-acrylate is found to be very efficient. Remarkably, 10 of the 23 chalcones were completely new and even never synthesized prior to this work (chalcones4,5,7,8,9,10,12,15,16and21). By using computational quantum chemistry, fluorescence, steady-state photolysis, and electron spin resonance spin-trapping techniques, the photoinitiation mechanism of three-component photoinitiating systems based on chalcones/Iod/EDB is clarified. The results demonstrate that several chalcone-based PISs can initiate free radical photopolymerization. Moreover, the developed chalcone-based three-component systems are applied to generate 3D hydrogel patterns using the 3D laser write technology. This research provides some novel insights into photopolymerization reactions with three-component photoinitiating systems used for 3D printing of hydrogels.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The design and development of high-performance photoinitiating systems applicable to visible light delivered from light-emitting diodes (LEDs) attract ever-increasing attention due to their great potential applications in various fields. Chalcones belong to a well-established class of natural compounds present in many plants. In this context, photoinitiators based on the scaffolds of natural compounds have probably great potential to open the way for non-toxic photoinitiators in the manufacturing of biocompatible polymer materials. In this work, 23 different chalcones selected fromin silicomolecular design (i.e.through molecular orbital calculations) were used in conjunction with an aminei.e.ethyl 4-(dimethylamino) benzoate (EDB) and an iodonium salt (bis-(4-tert-butylphenyl)iodonium hexafluorophosphate, Iod) to form photoinitiating systems (PISs) capable of initiating the polymerization of polyethylene glycol (600) diacrylate (PEG-diacrylate)viaan oxidation-reduction reaction mechanism. The formation of hydrogels by the photopolymerization of PEG-acrylate is found to be very efficient. Remarkably, 10 of the 23 chalcones were completely new and even never synthesized prior to this work (chalcones4,5,7,8,9,10,12,15,16and21). By using computational quantum chemistry, fluorescence, steady-state photolysis, and electron spin resonance spin-trapping techniques, the photoinitiation mechanism of three-component photoinitiating systems based on chalcones/Iod/EDB is clarified. The results demonstrate that several chalcone-based PISs can initiate free radical photopolymerization. Moreover, the developed chalcone-based three-component systems are applied to generate 3D hydrogel patterns using the 3D laser write technology. This research provides some novel insights into photopolymerization reactions with three-component photoinitiating systems used for 3D printing of hydrogels. |
Tomal, Wiktoria; Pilch, Maciej; Chachaj-Brekiesz, Anna; Galek, Mariusz; Morlet-Savary, Fabrice; Graff, Bernadette; Dietlin, Cline; Lalevee, Jacques; Ortyl, Joanna Photoinitiator-catalyst systems based onmeta-terphenyl derivatives as photosensitisers of iodonium and thianthrenium salts for visible photopolymerization in 3D printing processes (Article de journal) Polymer Chemistry, 11 (28), p. 4604–4621, 2020. @article{Tomal2020, title = {Photoinitiator-catalyst systems based onmeta-terphenyl derivatives as photosensitisers of iodonium and thianthrenium salts for visible photopolymerization in 3D printing processes}, author = { Wiktoria Tomal and Maciej Pilch and Anna Chachaj-Brekiesz and Mariusz Galek and Fabrice Morlet-Savary and Bernadette Graff and Cline Dietlin and Jacques Lalevee and Joanna Ortyl}, doi = {10.1039/d0py00597e}, year = {2020}, date = {2020-07-01}, journal = {Polymer Chemistry}, volume = {11}, number = {28}, pages = {4604--4621}, abstract = {This work demonstrates a new versatile, efficient photoinitiating system based on 2-amino-4-phenyl-6-(4-phenylphenyl)benzene-1,3-dicarbonitrile and 2-amino-4-phenyl-6-[4-[(E)-styryl]phenyl]benzene-1,3-dicarbonitrile derivatives as photosensitisers of iodonium and thianthrenium salts for photopolymerization under visible low light intensity with potential translation to high performance 3D printing. The newmeta-terphenyl derivatives were characterised by standard analytical and spectroscopic techniques. The activity of new bimolecular photoinitiating systems was investigated using Fourier transform real-time infrared spectroscopy. As the choices for an efficient visible sensitiser are rather limited for thianthrenium salt, the syntheses of new photo-sensitisers have received considerable attention. Therefore, the main goal of this study was to applymeta-terphenyl derivatives as visible photosensitisers for different types of onium salts. For this purpose, the new 2-amino-4-phenyl-6-(4-phenylphenyl)benzene-1,3-dicarbonitrile and 2-amino-4-phenyl-6-[4-[(E)-styryl]phenyl]benzene-1,3-dicarbonitrile derivatives were combined with commercially available iodonium salt (HIP) and thianthrenium salt to create visible light photoinitiating systems. It was shown that the efficiency of these bimolecular photoinitiating systems was based on the favorable free energy change of the photoinduced electron transfer from themeta-terphenyl derivatives to the iodonium and thianthrenium salts. It was confirmed by the experiments that the ability of tested photoredox pairs to initiate the photopolymerization processes depends on the oxidation potentials of themeta-terphenyl derivatives and the reduction potentials of the onium salts. Here, we explore the role of the scientific aspects of the mechanism, energetics and dynamics of applicability of the newmeta-terphenyl compounds as efficient and versatile photosensitisers of onium salts with different oxidising power. Moreover, the investigated terphenyl derivatives can work as photoredox catalysts and efficient photoinitiating systems, and can be used with typical oxidation and reduction agents in both reductive and oxidation cycles.}, keywords = {}, pubstate = {published}, tppubtype = {article} } This work demonstrates a new versatile, efficient photoinitiating system based on 2-amino-4-phenyl-6-(4-phenylphenyl)benzene-1,3-dicarbonitrile and 2-amino-4-phenyl-6-[4-[(E)-styryl]phenyl]benzene-1,3-dicarbonitrile derivatives as photosensitisers of iodonium and thianthrenium salts for photopolymerization under visible low light intensity with potential translation to high performance 3D printing. The newmeta-terphenyl derivatives were characterised by standard analytical and spectroscopic techniques. The activity of new bimolecular photoinitiating systems was investigated using Fourier transform real-time infrared spectroscopy. As the choices for an efficient visible sensitiser are rather limited for thianthrenium salt, the syntheses of new photo-sensitisers have received considerable attention. Therefore, the main goal of this study was to applymeta-terphenyl derivatives as visible photosensitisers for different types of onium salts. For this purpose, the new 2-amino-4-phenyl-6-(4-phenylphenyl)benzene-1,3-dicarbonitrile and 2-amino-4-phenyl-6-[4-[(E)-styryl]phenyl]benzene-1,3-dicarbonitrile derivatives were combined with commercially available iodonium salt (HIP) and thianthrenium salt to create visible light photoinitiating systems. It was shown that the efficiency of these bimolecular photoinitiating systems was based on the favorable free energy change of the photoinduced electron transfer from themeta-terphenyl derivatives to the iodonium and thianthrenium salts. It was confirmed by the experiments that the ability of tested photoredox pairs to initiate the photopolymerization processes depends on the oxidation potentials of themeta-terphenyl derivatives and the reduction potentials of the onium salts. Here, we explore the role of the scientific aspects of the mechanism, energetics and dynamics of applicability of the newmeta-terphenyl compounds as efficient and versatile photosensitisers of onium salts with different oxidising power. Moreover, the investigated terphenyl derivatives can work as photoredox catalysts and efficient photoinitiating systems, and can be used with typical oxidation and reduction agents in both reductive and oxidation cycles. |
Daou, Jean T; Santos, Thomas Dos; Nouali, Habiba; Josien, Ludovic; Michelin, Laure; Pieuchot, Laurent; Dutournie, Patrick Synthesis of FAU-Type Zeolite Membranes with Antimicrobial Activity. (Article de journal) Molecules (Basel, Switzerland), 25 (15), 2020. @article{Daou2020, title = {Synthesis of FAU-Type Zeolite Membranes with Antimicrobial Activity.}, author = { T. Jean Daou and Thomas Dos Santos and Habiba Nouali and Ludovic Josien and Laure Michelin and Laurent Pieuchot and Patrick Dutournie}, doi = {10.3390/molecules25153414}, year = {2020}, date = {2020-07-01}, journal = {Molecules (Basel, Switzerland)}, volume = {25}, number = {15}, abstract = {In this study, a layer of a pure and dense phase of FAU-type zeolite was synthesized directly on the surface of alpha-Al2O3 plane macroporous support. Before hydrothermal synthesis, a step of cleaning of the support by an anionic detergent was performed, a roughness surface is created, allowing the anchoring of the zeolite nuclei and then their growth, favoring in this sense the formation of a homogeneous zeolite layer. The obtained membranes were fully characterized using X-ray diffraction analysis (XRD), nitrogen sorption, scanning electron microscopy (SEM), and mercury porosimetry. After 24 h of thermal treatment at 75 °C, a homogeneous zeolite layer composed of bipyramidal crystals of FAU-type zeolite is obtained with a thickness of about 2.5 m. No obvious defects or cracks can be observed. It was found that the increase in heating temperature could lead to the appearance of an impurity phase, GIS-type zeolite. Then the ideal zeolite membrane was exchanged with Ag+ or Zn2+ cations to studies their antimicrobial properties. Zeolites membranes exchanged with Ag+ showed an agar-diffusive bactericidal activity against gram negative Escherichia coli (E. coli) bacteria. Zn2+ exchanged zeolite membrane presented a bacteriostatic activity that is less diffusive in agar. As expected, non-exchanged zeolite membrane (in its Na+ form) have no effect on bacterial activity. This process is particularly interesting for the synthesis of a good quality FAU-type zeolite membranes with antimicrobial properties.}, keywords = {}, pubstate = {published}, tppubtype = {article} } In this study, a layer of a pure and dense phase of FAU-type zeolite was synthesized directly on the surface of alpha-Al2O3 plane macroporous support. Before hydrothermal synthesis, a step of cleaning of the support by an anionic detergent was performed, a roughness surface is created, allowing the anchoring of the zeolite nuclei and then their growth, favoring in this sense the formation of a homogeneous zeolite layer. The obtained membranes were fully characterized using X-ray diffraction analysis (XRD), nitrogen sorption, scanning electron microscopy (SEM), and mercury porosimetry. After 24 h of thermal treatment at 75 °C, a homogeneous zeolite layer composed of bipyramidal crystals of FAU-type zeolite is obtained with a thickness of about 2.5 m. No obvious defects or cracks can be observed. It was found that the increase in heating temperature could lead to the appearance of an impurity phase, GIS-type zeolite. Then the ideal zeolite membrane was exchanged with Ag+ or Zn2+ cations to studies their antimicrobial properties. Zeolites membranes exchanged with Ag+ showed an agar-diffusive bactericidal activity against gram negative Escherichia coli (E. coli) bacteria. Zn2+ exchanged zeolite membrane presented a bacteriostatic activity that is less diffusive in agar. As expected, non-exchanged zeolite membrane (in its Na+ form) have no effect on bacterial activity. This process is particularly interesting for the synthesis of a good quality FAU-type zeolite membranes with antimicrobial properties. |
Avila, Margarita Romero; Leon-Rojas, Andres Felipe; Lacroix, Pascal G; Malfant, Isabelle; Farfan, Norberto; Mhanna, Rana; Santillan, Rosa; Ramos-Ortiz, Gabriel; Malval, Jean-Pierre Two-Photon-Triggered NO Release via a Ruthenium-Nitrosyl Complex with a Star-Shaped Architecture. (Article de journal) The journal of physical chemistry letters, p. 6487–6491, 2020. @article{RomeroAvila2020, title = {Two-Photon-Triggered NO Release via a Ruthenium-Nitrosyl Complex with a Star-Shaped Architecture.}, author = { Margarita Romero Avila and Andres Felipe Leon-Rojas and Pascal G. Lacroix and Isabelle Malfant and Norberto Farfan and Rana Mhanna and Rosa Santillan and Gabriel Ramos-Ortiz and Jean-Pierre Malval}, doi = {10.1021/acs.jpclett.0c01953}, year = {2020}, date = {2020-07-01}, journal = {The journal of physical chemistry letters}, pages = {6487--6491}, abstract = {We report herein a molecular engineering strategy based on the design of a multipolar ruthenium-nitrosyl (Ru-NO) complex with a three-branched architecture. The three Ru-NO units are introduced at the periphery of a highly pi-delocalized truxene core bearing three terpyridine ligands. The two-photon absorption capabilities of the complex were investigated by the Z-scan technique. The strong electronic coupling among the individual arms gives rise to a very strong two-photon absorption response (delta800nm 1600 GM), which corresponds to a 16-fold enhancement of the capability of a single-arm reference, thereby promoting an efficient light-driven NO release process in aqueous media.}, keywords = {}, pubstate = {published}, tppubtype = {article} } We report herein a molecular engineering strategy based on the design of a multipolar ruthenium-nitrosyl (Ru-NO) complex with a three-branched architecture. The three Ru-NO units are introduced at the periphery of a highly pi-delocalized truxene core bearing three terpyridine ligands. The two-photon absorption capabilities of the complex were investigated by the Z-scan technique. The strong electronic coupling among the individual arms gives rise to a very strong two-photon absorption response (delta800nm 1600 GM), which corresponds to a 16-fold enhancement of the capability of a single-arm reference, thereby promoting an efficient light-driven NO release process in aqueous media. |
Dika, Ihab; Diot, Frederic; Bardinal, Veronique; Malval, Jean-Pierre; Ecoffet, Carole; Bruyant, Aurelien; Barat, David; Reig, Benjamin; Doucet, Jean-Baptiste; Camps, Thierry; Soppera, Olivier Near infraredphotopolymer for micro-optics applications (Article de journal) Journal of Polymer Science, 58 (13), p. 1796–1809, 2020. @article{Dika2020, title = {Near infraredphotopolymer for micro-optics applications}, author = { Ihab Dika and Frederic Diot and Veronique Bardinal and Jean-Pierre Malval and Carole Ecoffet and Aurelien Bruyant and David Barat and Benjamin Reig and Jean-Baptiste Doucet and Thierry Camps and Olivier Soppera}, doi = {10.1002/pol.20200106}, year = {2020}, date = {2020-07-01}, journal = {Journal of Polymer Science}, volume = {58}, number = {13}, pages = {1796--1809}, abstract = {Near infrared (NIR) activable photopolymers suitable for versatile fabrication of micro-optical elements were developed. The first main objective of this article is to show that these new photopolymers can be used for microfabrication and investigate the parameters governing the microfabrication process. The impact of photonic, physico-chemical, and chemical parameters is discussed. High quality microstructures with a good control over their size and shape are demonstrated. The second main objective is to show practical examples of microlenses and waveguides implemented on single core and multiple core optical fibers, VCSELs, and glass slides are then presented. The NIR photosensitivity of this negative tone photoresists allows using the device source itself as to start the crosslinking process, which constitutes a convenient approach for micro-optics self-positioning on NIR sources and justifies the interest of such NIR photopolymer for the fabrication micro-optical elements and optical interconnects.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Near infrared (NIR) activable photopolymers suitable for versatile fabrication of micro-optical elements were developed. The first main objective of this article is to show that these new photopolymers can be used for microfabrication and investigate the parameters governing the microfabrication process. The impact of photonic, physico-chemical, and chemical parameters is discussed. High quality microstructures with a good control over their size and shape are demonstrated. The second main objective is to show practical examples of microlenses and waveguides implemented on single core and multiple core optical fibers, VCSELs, and glass slides are then presented. The NIR photosensitivity of this negative tone photoresists allows using the device source itself as to start the crosslinking process, which constitutes a convenient approach for micro-optics self-positioning on NIR sources and justifies the interest of such NIR photopolymer for the fabrication micro-optical elements and optical interconnects. |
Azzaz, Ahmed Amine; Khiari, Besma; Jellali, Salah; Ghimbeu, Cam Elia Matei; Jeguirim, Mejdi Hydrochars production, characterization and application for wastewater treatment: A review (Article de journal) Renewable & Sustainable Energy Reviews, 127 , p. 109882, 2020. @article{Azzaz2020b, title = {Hydrochars production, characterization and application for wastewater treatment: A review}, author = { Ahmed Amine Azzaz and Besma Khiari and Salah Jellali and Cam Elia Matei Ghimbeu and Mejdi Jeguirim}, doi = {10.1016/j.rser.2020.109882}, year = {2020}, date = {2020-07-01}, journal = {Renewable & Sustainable Energy Reviews}, volume = {127}, pages = {109882}, abstract = {Hydrothermal carbonization (HTC) of wet solid wastes has been pointed out as an eco-friendly, flexible and highly efficient technology for the sustainable valorization of multiple sourced wastes. In this review paper, most recent studies on hydrochars (solid residue of the HTC process) production, characterization and application for wastewaters treatment was summarized and deeply discussed. The role of initial feedstock source nature and characteristics as well as the HTC experimental conditions including the temperature, the residence time and the pH media was assessed. Physical and chemical activation methods including the use of oxygen, steam, microwave, acids, alkaline, organics and salty solutions for the improvement of the physicochemical properties of the produced hydrochars are compared. The efficiency of these raw/modified hydrochars along with the involved mechanisms during organic (dyes) and mineral pollutants (heavy metals and nutrients) removal from aqueous solutions is also reviewed. Finally, this paper addresses the main challenges and also demonstrates insights on new directions for hydrochars research and development in the future.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Hydrothermal carbonization (HTC) of wet solid wastes has been pointed out as an eco-friendly, flexible and highly efficient technology for the sustainable valorization of multiple sourced wastes. In this review paper, most recent studies on hydrochars (solid residue of the HTC process) production, characterization and application for wastewaters treatment was summarized and deeply discussed. The role of initial feedstock source nature and characteristics as well as the HTC experimental conditions including the temperature, the residence time and the pH media was assessed. Physical and chemical activation methods including the use of oxygen, steam, microwave, acids, alkaline, organics and salty solutions for the improvement of the physicochemical properties of the produced hydrochars are compared. The efficiency of these raw/modified hydrochars along with the involved mechanisms during organic (dyes) and mineral pollutants (heavy metals and nutrients) removal from aqueous solutions is also reviewed. Finally, this paper addresses the main challenges and also demonstrates insights on new directions for hydrochars research and development in the future. |
Duverger, Eric; Boyer, Anne-Gaelle; Sauriat-Dorizon, Helene; Sonnet, Philippe; Stephan, Regis; Hanf, Marie-Christine; Riedel, Damien Two-Dimensional Functionalized Ultrathin Semi-Insulating CaF2 Layer on the Si(100) Surface at a Low Temperature for Molecular Electronic Decoupling (Article de journal) Acs Applied Materials & Interfaces, 12 (26), p. 29661–29670, 2020. @article{Duverger2020, title = {Two-Dimensional Functionalized Ultrathin Semi-Insulating CaF2 Layer on the Si(100) Surface at a Low Temperature for Molecular Electronic Decoupling}, author = { Eric Duverger and Anne-Gaelle Boyer and Helene Sauriat-Dorizon and Philippe Sonnet and Regis Stephan and Marie-Christine Hanf and Damien Riedel}, doi = {10.1021/acsami.0c06631}, year = {2020}, date = {2020-07-01}, journal = {Acs Applied Materials & Interfaces}, volume = {12}, number = {26}, pages = {29661--29670}, abstract = {The ability to precisely control the electronic coupling/decoupling of adsorbates from surfaces is an essential goal. It is important for fundamental studies not only in surface science but also in several applied domains including, for example, miniaturized molecular electronic or for the development of various devices such as nanoscale biosensors or photovoltaic cells. Here, we provide atomic-scale experimental and theoretical investigations of a semi-insulating layer grown on a silicon surface via its epitaxy with CaF2. We show that, following the formation of a wetting layer, the ensuing organized unit cells are coupled to additional physisorbed CaF2 molecules, periodically located in their surroundings. This configuration shapes the formation of ribbons of stripes that functionalize the semiconductor surface. The obtained assembly, having a monolayer thickness, reveals a surface gap energy of similar to 3.2 eV. The adsorption of iron tetraphenylporphyrin molecules on the ribbons of stripes is used to estimate the electronic insulating properties of this structure via differential conductance measurements. Density functional theory (DFT) including several levels of complexity (annealing, DFT + U, and nonlocal van der Waals functionals) is employed to reproduce our experimental observations. Our findings offer a unique and robust template that brings an alternative solution to electronic semi-insulating layers on metal surfaces such as NaCl. Hence, CaF2/Si(100) ribbon of stripe structures, whose lengths can reach more than 100 nm, can be used as a versatile surface platform for various atomic-scale studies of molecular devices.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The ability to precisely control the electronic coupling/decoupling of adsorbates from surfaces is an essential goal. It is important for fundamental studies not only in surface science but also in several applied domains including, for example, miniaturized molecular electronic or for the development of various devices such as nanoscale biosensors or photovoltaic cells. Here, we provide atomic-scale experimental and theoretical investigations of a semi-insulating layer grown on a silicon surface via its epitaxy with CaF2. We show that, following the formation of a wetting layer, the ensuing organized unit cells are coupled to additional physisorbed CaF2 molecules, periodically located in their surroundings. This configuration shapes the formation of ribbons of stripes that functionalize the semiconductor surface. The obtained assembly, having a monolayer thickness, reveals a surface gap energy of similar to 3.2 eV. The adsorption of iron tetraphenylporphyrin molecules on the ribbons of stripes is used to estimate the electronic insulating properties of this structure via differential conductance measurements. Density functional theory (DFT) including several levels of complexity (annealing, DFT + U, and nonlocal van der Waals functionals) is employed to reproduce our experimental observations. Our findings offer a unique and robust template that brings an alternative solution to electronic semi-insulating layers on metal surfaces such as NaCl. Hence, CaF2/Si(100) ribbon of stripe structures, whose lengths can reach more than 100 nm, can be used as a versatile surface platform for various atomic-scale studies of molecular devices. |
Bruneau, Marion; Brendle, Jocelyne; Bennici, Simona; Limousy, Lionel; Pluchon, Sylvain Talc-like hybrids: influence of the synthesis (Article de journal) New Journal of Chemistry, 44 (25), p. 10326–10333, 2020. @article{Bruneau2020, title = {Talc-like hybrids: influence of the synthesis}, author = { Marion Bruneau and Jocelyne Brendle and Simona Bennici and Lionel Limousy and Sylvain Pluchon}, doi = {10.1039/c9nj06298j}, year = {2020}, date = {2020-07-01}, journal = {New Journal of Chemistry}, volume = {44}, number = {25}, pages = {10326--10333}, abstract = {This study aims to understand how the synthesis parameters influence the formation of organic-inorganic hybrids having a talc like structure synthesized usingN-[3-(trimethoxysilyl)propyl]ethylenediamine as the silicon source. The hybrids have been analysed mainly by(29)Si solid-state NMR in order to access the condensation degree of the silicon species. The results have shown that the solvent and the synthesis duration have no influence on the condensation. The addition of water in the synthesis medium induces a strong decrease of the degree of polycondensation of the silicon species. A basic pH of the synthesis medium can also further decrease this parameter. Additional information has been provided by X-Ray Diffraction and Thermogravimetric analysis which allow highlighting a correlation between the Full Width at Half Maximum and the thermal stability of the hybrids synthesized in the presence of different amounts of water. This opens the possibility of modulating the polycondensation degree of the silicic species, the crystallinity and the thermal stability changing only one parameter.}, keywords = {}, pubstate = {published}, tppubtype = {article} } This study aims to understand how the synthesis parameters influence the formation of organic-inorganic hybrids having a talc like structure synthesized usingN-[3-(trimethoxysilyl)propyl]ethylenediamine as the silicon source. The hybrids have been analysed mainly by(29)Si solid-state NMR in order to access the condensation degree of the silicon species. The results have shown that the solvent and the synthesis duration have no influence on the condensation. The addition of water in the synthesis medium induces a strong decrease of the degree of polycondensation of the silicon species. A basic pH of the synthesis medium can also further decrease this parameter. Additional information has been provided by X-Ray Diffraction and Thermogravimetric analysis which allow highlighting a correlation between the Full Width at Half Maximum and the thermal stability of the hybrids synthesized in the presence of different amounts of water. This opens the possibility of modulating the polycondensation degree of the silicic species, the crystallinity and the thermal stability changing only one parameter. |
Telitel, Siham; Morris, Jason C; Guillaneuf, Yohann; Clement, Jean-Louis; Morlet-Savary, Fabrice; Spangenberg, Arnaud; Malval, Jean-Pierre; Lalevee, Jacques; Gigmes, Didier; Soppera, Olivier Laser Direct Writing of Arbitrary Complex Polymer Microstructures by Nitroxide-Mediated Photopolymerization. (Article de journal) ACS applied materials & interfaces, 12 (27), p. 30779–30786, 2020. @article{Telitel2020, title = {Laser Direct Writing of Arbitrary Complex Polymer Microstructures by Nitroxide-Mediated Photopolymerization.}, author = { Siham Telitel and Jason C. Morris and Yohann Guillaneuf and Jean-Louis Clement and Fabrice Morlet-Savary and Arnaud Spangenberg and Jean-Pierre Malval and Jacques Lalevee and Didier Gigmes and Olivier Soppera}, doi = {10.1021/acsami.0c06339}, year = {2020}, date = {2020-07-01}, journal = {ACS applied materials & interfaces}, volume = {12}, number = {27}, pages = {30779--30786}, abstract = {In this paper, we demonstrate the possibility of generating arbitrary polymer microstructures covalently linked to a first polymer layer by laser direct writing. At the molecular scale, the process relies on nitroxide-mediated photopolymerization triggered by a light-sensitive alkoxyamine. In addition to the proof of concept and examples of achievable structures, including multichemistry patterns and 3D structures, this paper aims at investigating the physicochemical phenomena involved under such conditions. In particular, the parameters influencing the repolymerization process are considered, and special attention is paid to the study of the impact of oxygen on the spatial control of the polymerization. Such a work opens many possibilities toward the fabrication of on-demand high-resolution (multi)functional polymer micro and nanostructures.}, keywords = {}, pubstate = {published}, tppubtype = {article} } In this paper, we demonstrate the possibility of generating arbitrary polymer microstructures covalently linked to a first polymer layer by laser direct writing. At the molecular scale, the process relies on nitroxide-mediated photopolymerization triggered by a light-sensitive alkoxyamine. In addition to the proof of concept and examples of achievable structures, including multichemistry patterns and 3D structures, this paper aims at investigating the physicochemical phenomena involved under such conditions. In particular, the parameters influencing the repolymerization process are considered, and special attention is paid to the study of the impact of oxygen on the spatial control of the polymerization. Such a work opens many possibilities toward the fabrication of on-demand high-resolution (multi)functional polymer micro and nanostructures. |
Ge, Dandan; Marguet, Sylvie; Issa, Ali; Jradi, Safi; Nguyen, Tien Hoa; Nahra, Mackrine; Beal, Jeremie; Deturche, Regis; Chen, Hongshi; Blaize, Sylvain; Plain, Jerome; Fiorini, Celine; Douillard, Ludovic; Soppera, Olivier; Dinh, Xuan Quyen; Dang, Cuong; Yang, Xuyong; Xu, Tao; Wei, Bin; Sun, Xiao Wei; Couteau, Christophe; Bachelot, Renaud Hybrid plasmonic nano-emitters with controlled single quantum emitter positioning on the local excitation field. (Article de journal) Nature communications, 11 (1), p. 3414–3414, 2020. @article{Ge2020b, title = {Hybrid plasmonic nano-emitters with controlled single quantum emitter positioning on the local excitation field.}, author = { Dandan Ge and Sylvie Marguet and Ali Issa and Safi Jradi and Tien Hoa Nguyen and Mackrine Nahra and Jeremie Beal and Regis Deturche and Hongshi Chen and Sylvain Blaize and Jerome Plain and Celine Fiorini and Ludovic Douillard and Olivier Soppera and Xuan Quyen Dinh and Cuong Dang and Xuyong Yang and Tao Xu and Bin Wei and Xiao Wei Sun and Christophe Couteau and Renaud Bachelot}, doi = {10.1038/s41467-020-17248-8}, year = {2020}, date = {2020-07-01}, journal = {Nature communications}, volume = {11}, number = {1}, pages = {3414--3414}, abstract = {Hybrid plasmonic nano-emitters based on the combination of quantum dot emitters (QD) and plasmonic nanoantennas open up new perspectives in the control of light. However, precise positioning of any active medium at the nanoscale constitutes a challenge. Here, we report on the optimal overlap of antenna's near-field and active medium whose spatial distribution is controlled via a plasmon-triggered 2-photon polymerization of a photosensitive formulation containing QDs. Au nanoparticles of various geometries are considered. The response of these hybrid nano-emitters is shown to be highly sensitive to the light polarization. Different light emission states are evidenced by photoluminescence measurements. These states correspond to polarization-sensitive nanoscale overlap between the exciting local field and the active medium distribution. The decrease of the QD concentration within the monomer formulation allows trapping of a single quantum dot in the vicinity of the Au particle. The latter objects show polarization-dependent switching in the single-photon regime.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Hybrid plasmonic nano-emitters based on the combination of quantum dot emitters (QD) and plasmonic nanoantennas open up new perspectives in the control of light. However, precise positioning of any active medium at the nanoscale constitutes a challenge. Here, we report on the optimal overlap of antenna's near-field and active medium whose spatial distribution is controlled via a plasmon-triggered 2-photon polymerization of a photosensitive formulation containing QDs. Au nanoparticles of various geometries are considered. The response of these hybrid nano-emitters is shown to be highly sensitive to the light polarization. Different light emission states are evidenced by photoluminescence measurements. These states correspond to polarization-sensitive nanoscale overlap between the exciting local field and the active medium distribution. The decrease of the QD concentration within the monomer formulation allows trapping of a single quantum dot in the vicinity of the Au particle. The latter objects show polarization-dependent switching in the single-photon regime. |
Choo, Min-Yee; Oi, Lee Eng; Daou, Jean T; Ling, Tau Chuan; Lin, Yu-Chuan; Centi, Gabriele; Ng, Eng-Poh; Juan, Joon Ching Deposition of NiO Nanoparticles on Nanosized Zeolite NaY for Production of Biofuel via Hydrogen-Free Deoxygenation. (Article de journal) Materials (Basel, Switzerland), 13 (14), 2020. @article{Choo2020, title = {Deposition of NiO Nanoparticles on Nanosized Zeolite NaY for Production of Biofuel via Hydrogen-Free Deoxygenation.}, author = { Min-Yee Choo and Lee Eng Oi and T. Jean Daou and Tau Chuan Ling and Yu-Chuan Lin and Gabriele Centi and Eng-Poh Ng and Joon Ching Juan}, doi = {10.3390/ma13143104}, year = {2020}, date = {2020-07-01}, journal = {Materials (Basel, Switzerland)}, volume = {13}, number = {14}, abstract = {Nickel-based catalysts play an important role in the hydrogen-free deoxygenation for the production of biofuel. The yield and quality of the biofuel are critically affected by the physicochemical properties of NiO supported on nanosized zeolite Y (Y65, crystal size of 65 nm). Therefore, 10 wt% NiO supported on Y65 synthesized by using impregnation (IM) and deposition-precipitation (DP) methods were investigated. It was found that preparation methods have a significant effect on the deoxygenation of triolein. The initial rate of the DP method (14.8 goil·h-1) was 1.5 times higher than that of the IM method (9.6 goil·h-1). The DP-Y65 showed the best deoxygenation performance with a 80.0% conversion and a diesel selectivity of 93.7% at 380 °C within 1 h. The outstanding performance from the DP method was due to the smaller NiO particle size (3.57 ± 0.40 nm), high accessibility (H.F value of 0.084), and a higher Bronsted to Lewis acidity (B/L) ratio (0.29), which has improved the accessibility and deoxygenation ability of the catalyst. The NH4+ released from the decomposition of the urea during the DP process increased the B/L ratio of zeolite NaY. As a result, the pretreatment to convert Na-zeolite to H-zeolite in a conventional zeolite synthesis can be avoided. In this regard, the DP method offers a one-pot synthesis to produce smaller NiO-supported nanosized zeolite NaY with a high B/L ratio, and it managed to produce a higher yield with selectivity towards green diesel via deoxygenation under a hydrogen-free condition.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Nickel-based catalysts play an important role in the hydrogen-free deoxygenation for the production of biofuel. The yield and quality of the biofuel are critically affected by the physicochemical properties of NiO supported on nanosized zeolite Y (Y65, crystal size of 65 nm). Therefore, 10 wt% NiO supported on Y65 synthesized by using impregnation (IM) and deposition-precipitation (DP) methods were investigated. It was found that preparation methods have a significant effect on the deoxygenation of triolein. The initial rate of the DP method (14.8 goil·h-1) was 1.5 times higher than that of the IM method (9.6 goil·h-1). The DP-Y65 showed the best deoxygenation performance with a 80.0% conversion and a diesel selectivity of 93.7% at 380 °C within 1 h. The outstanding performance from the DP method was due to the smaller NiO particle size (3.57 ± 0.40 nm), high accessibility (H.F value of 0.084), and a higher Bronsted to Lewis acidity (B/L) ratio (0.29), which has improved the accessibility and deoxygenation ability of the catalyst. The NH4+ released from the decomposition of the urea during the DP process increased the B/L ratio of zeolite NaY. As a result, the pretreatment to convert Na-zeolite to H-zeolite in a conventional zeolite synthesis can be avoided. In this regard, the DP method offers a one-pot synthesis to produce smaller NiO-supported nanosized zeolite NaY with a high B/L ratio, and it managed to produce a higher yield with selectivity towards green diesel via deoxygenation under a hydrogen-free condition. |
Breloy, Louise; Losantos, Raul; Sampedro, Diego; Marazzi, Marco; Malval, Jean-Pierre; Heo, Yun; Akimoto, Jun; Ito, Yoshihiro; Brezova, Vlasta; Versace, Davy-Louis Allyl amino-thioxanthone derivatives as highly efficient visible light H-donors and co-polymerizable photoinitiators (Article de journal) Polymer Chemistry, 11 (26), p. 4297–4312, 2020. @article{Breloy2020, title = {Allyl amino-thioxanthone derivatives as highly efficient visible light H-donors and co-polymerizable photoinitiators}, author = { Louise Breloy and Raul Losantos and Diego Sampedro and Marco Marazzi and Jean-Pierre Malval and Yun Heo and Jun Akimoto and Yoshihiro Ito and Vlasta Brezova and Davy-Louis Versace}, doi = {10.1039/d0py00551g}, year = {2020}, date = {2020-07-01}, journal = {Polymer Chemistry}, volume = {11}, number = {26}, pages = {4297--4312}, abstract = {This study describes the role of two novel visible-light sensitive mono-allyl (TXA) and di-allyl sulfone (TXo2A) thioxanthone derivatives as photosensitizers and photoinitiators (PIs) for free-radical and cationic polymerizations (FRP and CP) and thiol-ene processes upon visible-light emitting diode exposure (LEDs@405 nm, 455 and 470 nm). The photoactivable groups incorporated into TXA and TXo2A have extended their absorption to the visible region up to 510 nm. TXo2A is the first example of a monomeric photoinitiator having two allyl side-chain groups. These new photoinitiating systems have first demonstrated unambiguously that they can be used as PIs and H donor molecules upon visible LED irradiation for the FRP of acrylates without additives. TXA and TXo2A also show highly efficient initiating properties when associated with judicious co-initiatorsi.e.an iodonium salt (Iod) as an electron acceptor, a tertiary amine (methyldiethanol amine, MDEA) as an electron donor, or a thiol derivative (trimethylolpropane tris (3-mercaptopropionate, TT) as a H-donor, under air and in laminate, for FRP, CP and thiol-ene reactions. These unprecedented initiating combinations promote high acrylate and epoxy conversions even under air, with a higher efficiency than the well-known CQ (and TX)-based photoinitiating systems used as references. As evidenced by nanosecond laser flash photolysis (LFP), electron paramagnetic resonance spin-trapping (EPR ST) and fluorescence/phosphorescence experiments, TXA (or TXo2A) can play a triple role, first as a proton/proton-coupled electron transfer initiator using MDEA or TT, as an electron donor when associated with Iod, and free-radical PIs following an intermolecular electron/proton transfer reaction. Interestingly, the photoinduced 3D interpenetrated polymer network (IPN) synthesizedviathe concomitant FRP and CP of an acrylate/epoxide monomer mixture upon LED@405 or 455 nm exposure has shown the capability to support viable cell proliferation without any cytotoxicity.}, keywords = {}, pubstate = {published}, tppubtype = {article} } This study describes the role of two novel visible-light sensitive mono-allyl (TXA) and di-allyl sulfone (TXo2A) thioxanthone derivatives as photosensitizers and photoinitiators (PIs) for free-radical and cationic polymerizations (FRP and CP) and thiol-ene processes upon visible-light emitting diode exposure (LEDs@405 nm, 455 and 470 nm). The photoactivable groups incorporated into TXA and TXo2A have extended their absorption to the visible region up to 510 nm. TXo2A is the first example of a monomeric photoinitiator having two allyl side-chain groups. These new photoinitiating systems have first demonstrated unambiguously that they can be used as PIs and H donor molecules upon visible LED irradiation for the FRP of acrylates without additives. TXA and TXo2A also show highly efficient initiating properties when associated with judicious co-initiatorsi.e.an iodonium salt (Iod) as an electron acceptor, a tertiary amine (methyldiethanol amine, MDEA) as an electron donor, or a thiol derivative (trimethylolpropane tris (3-mercaptopropionate, TT) as a H-donor, under air and in laminate, for FRP, CP and thiol-ene reactions. These unprecedented initiating combinations promote high acrylate and epoxy conversions even under air, with a higher efficiency than the well-known CQ (and TX)-based photoinitiating systems used as references. As evidenced by nanosecond laser flash photolysis (LFP), electron paramagnetic resonance spin-trapping (EPR ST) and fluorescence/phosphorescence experiments, TXA (or TXo2A) can play a triple role, first as a proton/proton-coupled electron transfer initiator using MDEA or TT, as an electron donor when associated with Iod, and free-radical PIs following an intermolecular electron/proton transfer reaction. Interestingly, the photoinduced 3D interpenetrated polymer network (IPN) synthesizedviathe concomitant FRP and CP of an acrylate/epoxide monomer mixture upon LED@405 or 455 nm exposure has shown the capability to support viable cell proliferation without any cytotoxicity. |
Mokbel, Halfaa; Dumur, Frederic; Lalevee, Jacques On demand NIR activated photopolyaddition reactions (Article de journal) Polymer Chemistry, 11 (26), p. 4250–4259, 2020. @article{Mokbel2020, title = {On demand NIR activated photopolyaddition reactions}, author = { Halfaa Mokbel and Frederic Dumur and Jacques Lalevee}, doi = {10.1039/d0py00639d}, year = {2020}, date = {2020-07-01}, journal = {Polymer Chemistry}, volume = {11}, number = {26}, pages = {4250--4259}, abstract = {A new approach based on a photoactivation process is proposed for the polyaddition reaction of epoxy-based systemsi.e.both for epoxy/amine and epoxy/anhydride processes that are characterized by huge applications in polymers (e.g.composite and adhesive fields). Outstandingly, for the first time, near-infrared (NIR) absorbing dyes are used here for this photoactivated approach upon NIR light, providing safe irradiation conditions. Indeed, the use of NIR light remains a huge challengei.e.the photon energy is extremely low to initiate photochemical processes. But a main advantage of the NIR light for polymer synthesis is a deeper light penetration into the material. A photoinitiating system is proposed comprising a NIR dye combined with an iodonium salt for the epoxy/amine photopolyaddition. The new proposed approach is highly robust and can be used for a broad selection of amines and epoxides. In the case of epoxy/anhydride photopolyaddition, the presence of an accelerator is required to improve the reaction. Additionally, the use of NIR light has a huge effect on the kinetics of reaction: the polymerization time is greatly improved compared to the classical reaction (e.g.in 3 hours without lightvs.a few seconds or minutes upon NIR light irradiation, at room temperature). Two irradiation wavelengths are presented here: 785 nm and 1064 nm with two selected NIR dyes. The different systems presented in this paper exhibit fast polymerizations associated with full conversions. Real-time Fourier transform infrared spectroscopy is used to follow the polymerization kinetics. The applications in adhesives as well as composites are presented to highlight the interest of these NIR photoactivated processes. For the first time, on demand processes can be proposed for epoxy-amine and epoxy-anhydride polyadditionsi.e.these latter systems can be polymerized within a few seconds/minutes at room temperature upon NIR stimulusvs.more than 3 h without light.}, keywords = {}, pubstate = {published}, tppubtype = {article} } A new approach based on a photoactivation process is proposed for the polyaddition reaction of epoxy-based systemsi.e.both for epoxy/amine and epoxy/anhydride processes that are characterized by huge applications in polymers (e.g.composite and adhesive fields). Outstandingly, for the first time, near-infrared (NIR) absorbing dyes are used here for this photoactivated approach upon NIR light, providing safe irradiation conditions. Indeed, the use of NIR light remains a huge challengei.e.the photon energy is extremely low to initiate photochemical processes. But a main advantage of the NIR light for polymer synthesis is a deeper light penetration into the material. A photoinitiating system is proposed comprising a NIR dye combined with an iodonium salt for the epoxy/amine photopolyaddition. The new proposed approach is highly robust and can be used for a broad selection of amines and epoxides. In the case of epoxy/anhydride photopolyaddition, the presence of an accelerator is required to improve the reaction. Additionally, the use of NIR light has a huge effect on the kinetics of reaction: the polymerization time is greatly improved compared to the classical reaction (e.g.in 3 hours without lightvs.a few seconds or minutes upon NIR light irradiation, at room temperature). Two irradiation wavelengths are presented here: 785 nm and 1064 nm with two selected NIR dyes. The different systems presented in this paper exhibit fast polymerizations associated with full conversions. Real-time Fourier transform infrared spectroscopy is used to follow the polymerization kinetics. The applications in adhesives as well as composites are presented to highlight the interest of these NIR photoactivated processes. For the first time, on demand processes can be proposed for epoxy-amine and epoxy-anhydride polyadditionsi.e.these latter systems can be polymerized within a few seconds/minutes at room temperature upon NIR stimulusvs.more than 3 h without light. |
Xu, Yangyang; Noirbent, Guillaume; Brunel, Damien; Liu, Feiyang; Gigmes, Didier; Sun, Ke; Zhang, Yijun; Liu, Shaohui; Morlet-Savary, Fabrice; Xiao, Pu; Dumur, Frederic; Lalevee, Jacques Ketone derivatives as photoinitiators for both radical and cationic photopolymerizations under visible LED and application in 3D printing (Article de journal) European Polymer Journal, 132 , p. UNSP 109737, 2020. @article{Xu2020a, title = {Ketone derivatives as photoinitiators for both radical and cationic photopolymerizations under visible LED and application in 3D printing}, author = { Yangyang Xu and Guillaume Noirbent and Damien Brunel and Feiyang Liu and Didier Gigmes and Ke Sun and Yijun Zhang and Shaohui Liu and Fabrice Morlet-Savary and Pu Xiao and Frederic Dumur and Jacques Lalevee}, doi = {10.1016/j.eurpolymj.2020.109737}, year = {2020}, date = {2020-06-01}, journal = {European Polymer Journal}, volume = {132}, pages = {UNSP 109737}, abstract = {Six ketones (abbreviated as ketones 1-6) varying by the substitution pattern of the central cyclohexanones and the choice of the peripheral groups (thiophene or furane) were synthesized and proposed as unprecedented visible light sensitive photoinitiators, in combination with an amine and an iodonium salt, for the free radical polymerization of acrylates upon LED irradiation at 405 nm. For the photopolymerization of acrylates carried out as thin samples in laminate, all these ketones showed high photoinitiating abilities. Conversely, when tested as photoinitiators for thick samples, compared to the other 4 ketones, ketone 3 and ketone 5 both based onpiperidin-4-one as the central core and comprising furanes as peripheral groups proved to be the most efficient photoinitiators. Notably, the highest final polymerization conversion of Ebecryl 40, a tetrafunctional polyether acrylate, could be obtained using these two photoinitiators. The high photoreactivity of ketone 3 was highlighted by the steady state photolysis experiments. Meanwhile, ketone 3 could also promote the cationic polymerization of epoxides upon LED irradiation at 405 nm, in the presence of an iodonium salt. Interestingly, some 3D patterns could also be fabricated by free radical polymerization of Ebecryl 40 while using the ketone 3-based photoinitiating system.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Six ketones (abbreviated as ketones 1-6) varying by the substitution pattern of the central cyclohexanones and the choice of the peripheral groups (thiophene or furane) were synthesized and proposed as unprecedented visible light sensitive photoinitiators, in combination with an amine and an iodonium salt, for the free radical polymerization of acrylates upon LED irradiation at 405 nm. For the photopolymerization of acrylates carried out as thin samples in laminate, all these ketones showed high photoinitiating abilities. Conversely, when tested as photoinitiators for thick samples, compared to the other 4 ketones, ketone 3 and ketone 5 both based onpiperidin-4-one as the central core and comprising furanes as peripheral groups proved to be the most efficient photoinitiators. Notably, the highest final polymerization conversion of Ebecryl 40, a tetrafunctional polyether acrylate, could be obtained using these two photoinitiators. The high photoreactivity of ketone 3 was highlighted by the steady state photolysis experiments. Meanwhile, ketone 3 could also promote the cationic polymerization of epoxides upon LED irradiation at 405 nm, in the presence of an iodonium salt. Interestingly, some 3D patterns could also be fabricated by free radical polymerization of Ebecryl 40 while using the ketone 3-based photoinitiating system. |
Liu, Shaohui; Brunel, Damien; Sun, Ke; Xu, Yangyang; Morlet-Savary, Fabrice; Graff, Bernadette; Xiao, Pu; Dumur, Frederic; Lalevee, Jacques A monocomponent bifunctional benzophenone-carbazole type II photoinitiator for LED photoinitiating systems (Article de journal) Polymer Chemistry, 11 (21), p. 3551–3556, 2020. @article{Liu2020b, title = {A monocomponent bifunctional benzophenone-carbazole type II photoinitiator for LED photoinitiating systems}, author = { Shaohui Liu and Damien Brunel and Ke Sun and Yangyang Xu and Fabrice Morlet-Savary and Bernadette Graff and Pu Xiao and Frederic Dumur and Jacques Lalevee}, doi = {10.1039/d0py00644k}, year = {2020}, date = {2020-06-01}, journal = {Polymer Chemistry}, volume = {11}, number = {21}, pages = {3551--3556}, abstract = {A bifunctional benzophenone-carbazole-based photoinitiator (BPC) was designed from its molecular structure viewpoint. To achieve this, two benzoyl substituents were introduced as peripheral groups of carbazole, so that a molecule in which two benzophenones were fused to one carbazole unit could be obtained in a one-step procedure. As a result of this combination, synergetic effects are thus achieved. Interestingly, BPC could efficiently initiate the free radical photopolymerization (FRP) of acrylates without addition of any extra hydrogen donors, demonstrating that not only a monocomponent Type II behavior but also fast photoinitiation rates were obtained in the presence of an amine and/or an iodonium salt under LED@365 nm irradiation. Meanwhile, BPC can also interact with the iodonium salt to generate cationic species for the cationic photopolymerization (CP) of epoxides. BPC was found as a versatile photoinitiator that can be used for both radical and cationic polymerizations. The best photoinitiating system (PIS) determined during the FRP tests was selected for 3D printing experiments. Steady state photolysis and fluorescence quenching experiments were carried out to verify the interaction between BPC and the different additives in the excited state. Electron spin resonance-spin trapping experiments successfully distinguished the free radicals generated by the different PISs and the proposed electron transfer mechanisms are also discussed.}, keywords = {}, pubstate = {published}, tppubtype = {article} } A bifunctional benzophenone-carbazole-based photoinitiator (BPC) was designed from its molecular structure viewpoint. To achieve this, two benzoyl substituents were introduced as peripheral groups of carbazole, so that a molecule in which two benzophenones were fused to one carbazole unit could be obtained in a one-step procedure. As a result of this combination, synergetic effects are thus achieved. Interestingly, BPC could efficiently initiate the free radical photopolymerization (FRP) of acrylates without addition of any extra hydrogen donors, demonstrating that not only a monocomponent Type II behavior but also fast photoinitiation rates were obtained in the presence of an amine and/or an iodonium salt under LED@365 nm irradiation. Meanwhile, BPC can also interact with the iodonium salt to generate cationic species for the cationic photopolymerization (CP) of epoxides. BPC was found as a versatile photoinitiator that can be used for both radical and cationic polymerizations. The best photoinitiating system (PIS) determined during the FRP tests was selected for 3D printing experiments. Steady state photolysis and fluorescence quenching experiments were carried out to verify the interaction between BPC and the different additives in the excited state. Electron spin resonance-spin trapping experiments successfully distinguished the free radicals generated by the different PISs and the proposed electron transfer mechanisms are also discussed. |
Anfar, Zakaria; Fakir, Abdellah Ait El; Ahsaine, Hassan Ait; Zbair, Mohamed; Farsad, Salaheddine; Morlet-Savary, Fabrice; Jada, Amane; Alem, Noureddine El Nitrogen doped graphitic porous carbon from almond shells as an efficient persulfate activator for organic compound degradation (Article de journal) New Journal of Chemistry, 44 (22), p. 9391–9401, 2020. @article{Anfar2020b, title = {Nitrogen doped graphitic porous carbon from almond shells as an efficient persulfate activator for organic compound degradation}, author = { Zakaria Anfar and Abdellah Ait El Fakir and Hassan Ait Ahsaine and Mohamed Zbair and Salaheddine Farsad and Fabrice Morlet-Savary and Amane Jada and Noureddine El Alem}, doi = {10.1039/d0nj01148g}, year = {2020}, date = {2020-06-01}, journal = {New Journal of Chemistry}, volume = {44}, number = {22}, pages = {9391--9401}, abstract = {Here, we have developed a simple and efficient low-temperature process for doping N into graphitic porous carbon to prepare a catalyst: N-GPC. Almond shell (AS), as bio-sourced material, was used for graphitic porous carbon preparation via a new facile environmentally friendly approach followed by pyrolysis. The resulting powder was characterized by X-ray diffraction, X-ray photoelectron spectroscopy, Fourier-transform infrared spectroscopy, scanning electron microscopy, Raman spectroscopy and BET. The catalytic activity was investigated by using Orange-G (OG) as the target pollutant and N-GPC as the heterogeneous catalyst to activate persulfate (PS). The influence of various parameters such as temperature, PS concentration, catalyst dose, pH and time over the N-GPC/PS system was investigated. OG discoloration of 99% was achieved with a degradation rate of 70% using [N-GPC] = 0.2 g L-1, [OG] = 100 mg L-1 mM, and [PS] = 4 mM at ambient temperature and natural pH. The catalyst N-GPC could be recycled easily for three cycles with good stability. Moreover, quenching experiments and EPR analysis were investigated to elucidate the active radicals participating in the degradation process. The results indicated that O-1(2) is the most dominant non-radical species in the degradation process of OG. The enhanced activities of the N-GPC/PS system were attributed to the high surface area and generated charges from the surface of the prepared N-GPC. This strategy can lead to the achievement of sufficiently managed biomass waste to pave the way to environmentally friendly catalysis.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Here, we have developed a simple and efficient low-temperature process for doping N into graphitic porous carbon to prepare a catalyst: N-GPC. Almond shell (AS), as bio-sourced material, was used for graphitic porous carbon preparation via a new facile environmentally friendly approach followed by pyrolysis. The resulting powder was characterized by X-ray diffraction, X-ray photoelectron spectroscopy, Fourier-transform infrared spectroscopy, scanning electron microscopy, Raman spectroscopy and BET. The catalytic activity was investigated by using Orange-G (OG) as the target pollutant and N-GPC as the heterogeneous catalyst to activate persulfate (PS). The influence of various parameters such as temperature, PS concentration, catalyst dose, pH and time over the N-GPC/PS system was investigated. OG discoloration of 99% was achieved with a degradation rate of 70% using [N-GPC] = 0.2 g L-1, [OG] = 100 mg L-1 mM, and [PS] = 4 mM at ambient temperature and natural pH. The catalyst N-GPC could be recycled easily for three cycles with good stability. Moreover, quenching experiments and EPR analysis were investigated to elucidate the active radicals participating in the degradation process. The results indicated that O-1(2) is the most dominant non-radical species in the degradation process of OG. The enhanced activities of the N-GPC/PS system were attributed to the high surface area and generated charges from the surface of the prepared N-GPC. This strategy can lead to the achievement of sufficiently managed biomass waste to pave the way to environmentally friendly catalysis. |
Liu, Shaohui; Chen, Hong; Zhang, Yijun; Sun, Ke; Xu, Yangyang; Morlet-Savary, Fabrice; Graff, Bernadette; Noirbent, Guillaume; Pigot, Corentin; Brunel, Damien; Nechab, Malek; Gigmes, Didier; Xiao, Pu; Dumur, Frederic; Lalevee, Jacques Monocomponent Photoinitiators based on Benzophenone-Carbazole Structure for LED Photoinitiating Systems and Application on 3D Printing. (Article de journal) Polymers, 12 (6), 2020. @article{Liu2020a, title = {Monocomponent Photoinitiators based on Benzophenone-Carbazole Structure for LED Photoinitiating Systems and Application on 3D Printing.}, author = { Shaohui Liu and Hong Chen and Yijun Zhang and Ke Sun and Yangyang Xu and Fabrice Morlet-Savary and Bernadette Graff and Guillaume Noirbent and Corentin Pigot and Damien Brunel and Malek Nechab and Didier Gigmes and Pu Xiao and Frederic Dumur and Jacques Lalevee}, doi = {10.3390/polym12061394}, year = {2020}, date = {2020-06-01}, journal = {Polymers}, volume = {12}, number = {6}, abstract = {In this article, different substituents (benzoyl, acetyl, styryl) are introduced onto the carbazole scaffold to obtain 8 novel carbazole derivatives. Interestingly, a benzoyl substituent, connected to a carbazole group, could form a benzophenone moiety, which composes a monocomponent Type II benzophenone-carbazole photoinitiator (PI). The synergetic effect of the benzophenone moiety and the amine in the carbazole moiety is expected to produce high performance photoinitiating systems (PISs) for the free radical photopolymerization (FRP). For different substituents, clear effects on the light absorption properties are demonstrated using UV-Visible absorption spectroscopy. Benzophenone-carbazole PIs can initiate the FRP of acrylates alone (monocomponent Type II photoinitiator behavior). In addition, fast polymerization rates and high function conversions of acrylate are observed when an amine and/or an iodonium salt are added in systems. Benzophenone-carbazole PIs have good efficiencies in cationic photopolymerization (CP) upon LED @ 365 nm irradiation in the presence of iodonium salt. In contrast, other PIs without synergetic effect demonstrate unsatisfied photopolymerization profiles in the same conditions. The best PIS identified for the free radical photopolymerization were used in three-dimensional (3D) printing. Steady state photolysis and fluorescence quenching experiments were carried out to investigate the reactivity and the photochemistry and photophysical properties of PIs. The free radicals, generated from the studied PISs, are detected by the electron spin resonance - spin trapping technique. The proposed chemical mechanisms are provided and the structure/reactivity/efficiency relationships are also discussed. All the results showed that the benzophenone-carbazole PIs have a good application potential, and this work provides a rational design route for PI molecules. Remarkably, BPC2-BPC4, C6, C8 were never synthetized before; therefore, 5 of the 8 compounds are completely new.}, keywords = {}, pubstate = {published}, tppubtype = {article} } In this article, different substituents (benzoyl, acetyl, styryl) are introduced onto the carbazole scaffold to obtain 8 novel carbazole derivatives. Interestingly, a benzoyl substituent, connected to a carbazole group, could form a benzophenone moiety, which composes a monocomponent Type II benzophenone-carbazole photoinitiator (PI). The synergetic effect of the benzophenone moiety and the amine in the carbazole moiety is expected to produce high performance photoinitiating systems (PISs) for the free radical photopolymerization (FRP). For different substituents, clear effects on the light absorption properties are demonstrated using UV-Visible absorption spectroscopy. Benzophenone-carbazole PIs can initiate the FRP of acrylates alone (monocomponent Type II photoinitiator behavior). In addition, fast polymerization rates and high function conversions of acrylate are observed when an amine and/or an iodonium salt are added in systems. Benzophenone-carbazole PIs have good efficiencies in cationic photopolymerization (CP) upon LED @ 365 nm irradiation in the presence of iodonium salt. In contrast, other PIs without synergetic effect demonstrate unsatisfied photopolymerization profiles in the same conditions. The best PIS identified for the free radical photopolymerization were used in three-dimensional (3D) printing. Steady state photolysis and fluorescence quenching experiments were carried out to investigate the reactivity and the photochemistry and photophysical properties of PIs. The free radicals, generated from the studied PISs, are detected by the electron spin resonance - spin trapping technique. The proposed chemical mechanisms are provided and the structure/reactivity/efficiency relationships are also discussed. All the results showed that the benzophenone-carbazole PIs have a good application potential, and this work provides a rational design route for PI molecules. Remarkably, BPC2-BPC4, C6, C8 were never synthetized before; therefore, 5 of the 8 compounds are completely new. |
Figueiredo, Mariana P; Layrac, Geraldine; Hebraud, Anne; Limousy, Lionel; Brendle, Jocelyne; Schlatter, Guy; Constantino, Vera R L Design of 3D multi-layered electrospun membranes embedding iron-based layered double hydroxide for drug storage and control of sustained release (Article de journal) European Polymer Journal, 131 , p. UNSP 109675, 2020. @article{Figueiredo2020a, title = {Design of 3D multi-layered electrospun membranes embedding iron-based layered double hydroxide for drug storage and control of sustained release}, author = { Mariana P. Figueiredo and Geraldine Layrac and Anne Hebraud and Lionel Limousy and Jocelyne Brendle and Guy Schlatter and Vera R. L. Constantino}, doi = {10.1016/j.eurpolymj.2020.109675}, year = {2020}, date = {2020-05-01}, journal = {European Polymer Journal}, volume = {131}, pages = {UNSP 109675}, abstract = {Nowadays polymer dressings are expected to possess multiply functions. Besides acting as physical barriers, dressings may provide for the injured tissue species able to turn wound healing process faster and painless. In this way, dressings can be designed aiming to enable the release of drugs. The possibility to modulate drug release kinetics is a desired characteristic to be achieved in order to turn drug delivery systems adequate to specific treatments. However, hydrophilic drugs and hydrophobic polymers incompatibility hinders such modulation and a long-term release cannot be achieved efficiently. Here we present the design of poly(lactic acid) (PLA) membranes containing iron-based Layered Double Hydroxide (LDH) particles able to storage a hydrophilic anionic drug (derived from the non-steroidal anti-inflammatory naproxen). LDH particles are excellent candidates to compose multifunctional composites. They may present diverse biocompatible compositions, possess an elevated encapsulation capacity and tends to promote drugs sustained release by its own, besides assisting tissues regeneration process. Nanofibrous membranes were prepared by the combination of electrospun PLA and electrosprayed LDH as alternated layers (approach A) and also by both technics performed at the same time (approach B). In approach A, by varying the thickness of the PLA fibrous layers, it was possible to easily modulate the drug release rate. Half of drug content was released after 1, 4 and 17 days for the membranes containing the thinnest, the intermediate and the thicker PLA layers, respectively, and after 56 h for the membrane prepared by the approach B. Naproxen release was kept for 18 days for the thinnest membrane, 59 days for the membrane prepared by the approach B and 66 days for the thicker membranes. We believe that this work can inspire the development of new functional membranes with tunable drug release profile thanks to the versatile electrospinning and electrospraying techniques.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Nowadays polymer dressings are expected to possess multiply functions. Besides acting as physical barriers, dressings may provide for the injured tissue species able to turn wound healing process faster and painless. In this way, dressings can be designed aiming to enable the release of drugs. The possibility to modulate drug release kinetics is a desired characteristic to be achieved in order to turn drug delivery systems adequate to specific treatments. However, hydrophilic drugs and hydrophobic polymers incompatibility hinders such modulation and a long-term release cannot be achieved efficiently. Here we present the design of poly(lactic acid) (PLA) membranes containing iron-based Layered Double Hydroxide (LDH) particles able to storage a hydrophilic anionic drug (derived from the non-steroidal anti-inflammatory naproxen). LDH particles are excellent candidates to compose multifunctional composites. They may present diverse biocompatible compositions, possess an elevated encapsulation capacity and tends to promote drugs sustained release by its own, besides assisting tissues regeneration process. Nanofibrous membranes were prepared by the combination of electrospun PLA and electrosprayed LDH as alternated layers (approach A) and also by both technics performed at the same time (approach B). In approach A, by varying the thickness of the PLA fibrous layers, it was possible to easily modulate the drug release rate. Half of drug content was released after 1, 4 and 17 days for the membranes containing the thinnest, the intermediate and the thicker PLA layers, respectively, and after 56 h for the membrane prepared by the approach B. Naproxen release was kept for 18 days for the thinnest membrane, 59 days for the membrane prepared by the approach B and 66 days for the thicker membranes. We believe that this work can inspire the development of new functional membranes with tunable drug release profile thanks to the versatile electrospinning and electrospraying techniques. |
Chang, Po-Yi; Lin, Ching-Fu; Rouphael, Samer El Khoury; Huang, Ting-Hsuan; Wu, Chang-Mao; Berling, Dominique; Yeh, Ping-Hung; Lu, Chia-Jung; Meng, Hsin-Fei; Zan, Hsiao-Wen; Soppera, Olivier Near-Infrared Laser-Annealed IZO Flexible Device as a Sensitive H2S Sensor at Room Temperature. (Article de journal) ACS applied materials & interfaces, 2020. @article{Chang2020, title = {Near-Infrared Laser-Annealed IZO Flexible Device as a Sensitive H2S Sensor at Room Temperature.}, author = { Po-Yi Chang and Ching-Fu Lin and Samer El Khoury Rouphael and Ting-Hsuan Huang and Chang-Mao Wu and Dominique Berling and Ping-Hung Yeh and Chia-Jung Lu and Hsin-Fei Meng and Hsiao-Wen Zan and Olivier Soppera}, doi = {10.1021/acsami.0c03257}, year = {2020}, date = {2020-05-01}, journal = {ACS applied materials & interfaces}, abstract = {A metal-oxide material (indium zinc oxide [IZO]) device with near-infrared (NIR) laser annealing was demonstrated on both glass and bendable plastic substrates (polycarbonate, polyethylene, and polyethylene terephthalate). After only 60 s, the sheet resistance of IZO films annealed with a laser was comparable to that of thermal-annealed devices at temperatures in the range of 200-300 °C (1 h). XPS, ATR, and AFM were used to investigate the changes in the sheet resistance and correlate them to the composition and morphology of the thin film. Finally, the NIR-laser-annealed IZO films were demonstrated to be capable of detecting changes in humidity and serving as a highly sensitive gas sensor of hydrogen sulfide (in ppb concentration), with room-temperature operation on a bendable substrate.}, keywords = {}, pubstate = {published}, tppubtype = {article} } A metal-oxide material (indium zinc oxide [IZO]) device with near-infrared (NIR) laser annealing was demonstrated on both glass and bendable plastic substrates (polycarbonate, polyethylene, and polyethylene terephthalate). After only 60 s, the sheet resistance of IZO films annealed with a laser was comparable to that of thermal-annealed devices at temperatures in the range of 200-300 °C (1 h). XPS, ATR, and AFM were used to investigate the changes in the sheet resistance and correlate them to the composition and morphology of the thin film. Finally, the NIR-laser-annealed IZO films were demonstrated to be capable of detecting changes in humidity and serving as a highly sensitive gas sensor of hydrogen sulfide (in ppb concentration), with room-temperature operation on a bendable substrate. |
Confalonieri, Giorgia; Daou, Jean T; Nouali, Habiba; Arletti, Rossella; Ryzhikov, Andrey Energetic Performance of Pure Silica Zeolites under High-Pressure Intrusion of LiCl Aqueous Solutions: An Overview. (Article de journal) Molecules (Basel, Switzerland), 25 (9), 2020. @article{Confalonieri2020a, title = {Energetic Performance of Pure Silica Zeolites under High-Pressure Intrusion of LiCl Aqueous Solutions: An Overview.}, author = { Giorgia Confalonieri and T. Jean Daou and Habiba Nouali and Rossella Arletti and Andrey Ryzhikov}, doi = {10.3390/molecules25092145}, year = {2020}, date = {2020-05-01}, journal = {Molecules (Basel, Switzerland)}, volume = {25}, number = {9}, abstract = {An overview of all the studies on high-pressure intrusion-extrusion of LiCl aqueous solutions in hydrophobic pure silica zeolites (zeosils) for absorption and storage of mechanical energy is presented. Operational principles of heterogeneous lyophobic systems and their possible applications in the domains of mechanical energy storage, absorption, and generation are described. The intrusion of LiCl aqueous solutions instead of water allows to considerably increase energetic performance of zeosil-based systems by a strong rise of intrusion pressure. The intrusion pressure increases with the salt concentration and depends considerably on zeosil framework. In the case of channel-type zeosils, it rises with the decrease of pore opening diameter, whereas for cage-type ones, no clear trend is observed. A relative increase of intrusion pressure in comparison with water is particularly strong for the zeosils with narrow pore openings. The use of highly concentrated LiCl aqueous solutions instead of water can lead to a change of system behavior. This effect seems to be related to a lower formation of silanol defects under intrusion of solvated ions and a weaker interaction of the ions with silanol groups of zeosil framework. The influence of zeosil nanostructure on LiCl aqueous solutions intrusion-extrusion is also discussed.}, keywords = {}, pubstate = {published}, tppubtype = {article} } An overview of all the studies on high-pressure intrusion-extrusion of LiCl aqueous solutions in hydrophobic pure silica zeolites (zeosils) for absorption and storage of mechanical energy is presented. Operational principles of heterogeneous lyophobic systems and their possible applications in the domains of mechanical energy storage, absorption, and generation are described. The intrusion of LiCl aqueous solutions instead of water allows to considerably increase energetic performance of zeosil-based systems by a strong rise of intrusion pressure. The intrusion pressure increases with the salt concentration and depends considerably on zeosil framework. In the case of channel-type zeosils, it rises with the decrease of pore opening diameter, whereas for cage-type ones, no clear trend is observed. A relative increase of intrusion pressure in comparison with water is particularly strong for the zeosils with narrow pore openings. The use of highly concentrated LiCl aqueous solutions instead of water can lead to a change of system behavior. This effect seems to be related to a lower formation of silanol defects under intrusion of solvated ions and a weaker interaction of the ions with silanol groups of zeosil framework. The influence of zeosil nanostructure on LiCl aqueous solutions intrusion-extrusion is also discussed. |
Azzaz, Ahmed Amine; Jeguirim, Mejdi; Kinigopoulou, Vasiliki; Doulgeris, Charalampos; Goddard, Mary-Lorene; Jellali, Salah; Ghimbeu, Camelia Matei Olive mill wastewater: From a pollutant to green fuels, agricultural and water source and bio-fertilizer - Hydrothermal carbonization. (Article de journal) The Science of the total environment, 733 , p. 139314–139314, 2020. @article{Azzaz2020, title = {Olive mill wastewater: From a pollutant to green fuels, agricultural and water source and bio-fertilizer - Hydrothermal carbonization.}, author = { Ahmed Amine Azzaz and Mejdi Jeguirim and Vasiliki Kinigopoulou and Charalampos Doulgeris and Mary-Lorene Goddard and Salah Jellali and Camelia Matei Ghimbeu}, doi = {10.1016/j.scitotenv.2020.139314}, year = {2020}, date = {2020-05-01}, journal = {The Science of the total environment}, volume = {733}, pages = {139314--139314}, abstract = {Hydrothermal carbonization (HTC) is considered as a promising technique for wastes conversion into carbon rich materials for various energetic, environmental and agricultural applications. In this work, the HTC of olive mill wastewater (OMWW) was investigated at different temperatures (180-220°C) and both, the solid (i.e., hydrochars) and the final process liquid derived from the thermal conversion process were deeply analyzed. Results showed that the solid yield was affected by the temperature, i.e., decrease from 57% to 25% for temperatures of 180°C and 220°C, respectively. Furthermore, the hydrochars presented an increasing fixed carbon percentage with the increase of the carbonization temperature, suggesting that decarboxylation is the main reaction driving the HTC process. The decrease in the O/C ratio promoted an increase of the high heating value (HHV) by 32% for hydrochar prepared at 220°C. The process liquids were sampled and their organic contents were analyzed using GC-MS technique. Acids, alcohols, phenols and sugar derivatives were detected and their concentrations varied with carbonization temperatures. The assessment of the physico-chemical properties of the generated HTC by-products suggested the possible application of the hydrochars for energetic insights while the liquid fraction could be practical for in agricultural field.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Hydrothermal carbonization (HTC) is considered as a promising technique for wastes conversion into carbon rich materials for various energetic, environmental and agricultural applications. In this work, the HTC of olive mill wastewater (OMWW) was investigated at different temperatures (180-220°C) and both, the solid (i.e., hydrochars) and the final process liquid derived from the thermal conversion process were deeply analyzed. Results showed that the solid yield was affected by the temperature, i.e., decrease from 57% to 25% for temperatures of 180°C and 220°C, respectively. Furthermore, the hydrochars presented an increasing fixed carbon percentage with the increase of the carbonization temperature, suggesting that decarboxylation is the main reaction driving the HTC process. The decrease in the O/C ratio promoted an increase of the high heating value (HHV) by 32% for hydrochar prepared at 220°C. The process liquids were sampled and their organic contents were analyzed using GC-MS technique. Acids, alcohols, phenols and sugar derivatives were detected and their concentrations varied with carbonization temperatures. The assessment of the physico-chemical properties of the generated HTC by-products suggested the possible application of the hydrochars for energetic insights while the liquid fraction could be practical for in agricultural field. |
Noirbent, Guillaume; Xu, Yangyang; Bonardi, Aude-Heloise; Duval, Sylvain; Gigmes, Didier; Lalevee, Jacques; Dumur, Frederic New Donor-Acceptor Stenhouse Adducts as Visible and Near Infrared Light Polymerization Photoinitiators. (Article de journal) Molecules (Basel, Switzerland), 25 (10), 2020. @article{Noirbent2020, title = {New Donor-Acceptor Stenhouse Adducts as Visible and Near Infrared Light Polymerization Photoinitiators.}, author = { Guillaume Noirbent and Yangyang Xu and Aude-Heloise Bonardi and Sylvain Duval and Didier Gigmes and Jacques Lalevee and Frederic Dumur}, doi = {10.3390/molecules25102317}, year = {2020}, date = {2020-05-01}, journal = {Molecules (Basel, Switzerland)}, volume = {25}, number = {10}, abstract = {Polymerization photoinitiators that can be activated under low light intensity and in the visible range are being pursued by both the academic and industrial communities. To efficiently harvest light and initiate a polymerization process, dyes with high molar extinction coefficients in the visible range are ideal candidates. In this field, Donor-acceptor Stenhouse Adducts (DASA) which belong to a class of recently discovered organic photochromic molecules still lack practical applications. In this work, a series of DASA-based dyes are proposed as photoinitiators for the free radical polymerization of (meth)acrylates upon exposure to a near infrared light (laser diode at 785 nm).}, keywords = {}, pubstate = {published}, tppubtype = {article} } Polymerization photoinitiators that can be activated under low light intensity and in the visible range are being pursued by both the academic and industrial communities. To efficiently harvest light and initiate a polymerization process, dyes with high molar extinction coefficients in the visible range are ideal candidates. In this field, Donor-acceptor Stenhouse Adducts (DASA) which belong to a class of recently discovered organic photochromic molecules still lack practical applications. In this work, a series of DASA-based dyes are proposed as photoinitiators for the free radical polymerization of (meth)acrylates upon exposure to a near infrared light (laser diode at 785 nm). |
Figueiredo, Mariana P; Layrac, Geraldine; Hebraud, Anne; Limousy, Lionel; Brendle, Jocelyne; Schlatter, Guy; Constantino, Vera R L Design of 3D multi-layered electrospun membranes embedding iron-based layered double hydroxide for drug storage and control of sustained release (Article de journal) European Polymer Journal, 131 , p. 9675–9675, 2020. @article{Figueiredo2020, title = {Design of 3D multi-layered electrospun membranes embedding iron-based layered double hydroxide for drug storage and control of sustained release}, author = { Mariana P. Figueiredo and Geraldine Layrac and Anne Hebraud and Lionel Limousy and Jocelyne Brendle and Guy Schlatter and Vera R. L. Constantino}, year = {2020}, date = {2020-05-01}, journal = {European Polymer Journal}, volume = {131}, pages = {9675--9675}, abstract = {Nowadays polymer dressings are expected to possess multiply functions. Besides acting as physical barriers, dressings may provide for the injured tissue species able to turn wound healing process faster and painless. In this way, dressings can be designed aiming to enable the release of drugs. The possibility to modulate drug release kinetics is a desired characteristic to be achieved in order to turn drug delivery systems adequate to specific treatments. However, hydrophilic drugs and hydrophobic polymers incompatibility hinders such modulation and a long-term release cannot be achieved efficiently. Here we present the design of poly(lactic acid) (PLA) membranes containing iron-based Layered Double Hydroxide (LDH) particles able to storage a hydrophilic anionic drug (derived from the non-steroidal anti-inflammatory naproxen). LDH particles are excellent candidates to compose multifunctional composites. They may present diverse biocompatible compositions, possess an elevated encapsulation capacity and tends to promote drugs sustained release by its own, besides assisting tissues regeneration process. Nanofibrous membranes were prepared by the combination of electrospun PLA and electrosprayed LDH as alternated layers (approach A) and also by both technics performed at the same time (approach B). In approach A, by varying the thickness of the PLA fibrous layers, it was possible to easily modulate the drug release rate. Half of drug content was released after 1, 4 and 17 days for the membranes containing the thinnest, the intermediate and the thicker PLA layers, respectively, and after 56 h for the membrane prepared by the approach B. Naproxen release was kept for 18 days for the thinnest membrane, 59 days for the membrane prepared by the approach B and 66 days for the thicker membranes. We believe that this work can inspire the development of new functional membranes with tunable drug release profile thanks to the versatile electrospinning and electrospraying techniques.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Nowadays polymer dressings are expected to possess multiply functions. Besides acting as physical barriers, dressings may provide for the injured tissue species able to turn wound healing process faster and painless. In this way, dressings can be designed aiming to enable the release of drugs. The possibility to modulate drug release kinetics is a desired characteristic to be achieved in order to turn drug delivery systems adequate to specific treatments. However, hydrophilic drugs and hydrophobic polymers incompatibility hinders such modulation and a long-term release cannot be achieved efficiently. Here we present the design of poly(lactic acid) (PLA) membranes containing iron-based Layered Double Hydroxide (LDH) particles able to storage a hydrophilic anionic drug (derived from the non-steroidal anti-inflammatory naproxen). LDH particles are excellent candidates to compose multifunctional composites. They may present diverse biocompatible compositions, possess an elevated encapsulation capacity and tends to promote drugs sustained release by its own, besides assisting tissues regeneration process. Nanofibrous membranes were prepared by the combination of electrospun PLA and electrosprayed LDH as alternated layers (approach A) and also by both technics performed at the same time (approach B). In approach A, by varying the thickness of the PLA fibrous layers, it was possible to easily modulate the drug release rate. Half of drug content was released after 1, 4 and 17 days for the membranes containing the thinnest, the intermediate and the thicker PLA layers, respectively, and after 56 h for the membrane prepared by the approach B. Naproxen release was kept for 18 days for the thinnest membrane, 59 days for the membrane prepared by the approach B and 66 days for the thicker membranes. We believe that this work can inspire the development of new functional membranes with tunable drug release profile thanks to the versatile electrospinning and electrospraying techniques. |
Duplouy, Lucie; Moissette, Alain; Hureau, Matthieu; Waele, Vincent De; Daou, Jean T; Batonneau-Gener, Isabelle Effect of zeolite morphology on charge separated states: ZSM-5-type nanocrystals, nanosheets and nanosponges. (Article de journal) Physical chemistry chemical physics : PCCP, 2020. @article{Duplouy2020, title = {Effect of zeolite morphology on charge separated states: ZSM-5-type nanocrystals, nanosheets and nanosponges.}, author = { Lucie Duplouy and Alain Moissette and Matthieu Hureau and Vincent De Waele and T. Jean Daou and Isabelle Batonneau-Gener}, doi = {10.1039/d0cp01701a}, year = {2020}, date = {2020-05-01}, journal = {Physical chemistry chemical physics : PCCP}, abstract = {In the present work, we investigate the electron transfer occurring in the porous void of three MFI-type zeolite (ZSM-5) nanomaterials (nanocrystals, nanosheets and nanosponges) after adsorption and photoexcitation of t-stilbene (t-St). ZSM-5 nanosheets are constituted of lamellar stacking of several nanosheets (20-40 nm) where each nanosheet has a thickness of 2 nm. Nanosponges are composed of ZSM-5 nanocrystals (2-3 nm) separated by mesoporous holes of 5.8 nm facilitating the synthesis of hierachical materials. While the nanosheets show microporosity similar to that observed for the ZSM-5 nanocrystals, the absorption isotherms of the nanosponges show the existence of secondary micropores. After photoirradiation of t-St, UV-vis absorption spectroscopy shows the formation of charge separated states (radical cation and charge transfer complex) in the nanocrystals and in the nanosheets whereas no ionized species is detected in the nanosponges. The radical cation (RC) is stabilized in the nanosheets while it evolves very rapidly towards a Charge Transfer Complex (CTC) in the nanocrocrystals. The particular morphology of the nanosheets and nanosponges is put forward to explain this result since all host materials are of the MFI-type. To investigate ultra-short phenomena in the three nanomaterials, the UV-vis transient spectra were recorded between 2 and 450 mus after photoexcitation by nanosecond laser pulses. In the nanocrystals and nanosheets only the RC is detected whereas CTC formation is not observed. Photoexcitation of t-St in the nanosponges also leads to the formation of a RC but it recombines completely within 70 mus. This suggests the preferential location of t-St in the secondary micropores with pores larger than the micropores of the MFI-type framework and possibly in the mesopores of the nanosponges.}, keywords = {}, pubstate = {published}, tppubtype = {article} } In the present work, we investigate the electron transfer occurring in the porous void of three MFI-type zeolite (ZSM-5) nanomaterials (nanocrystals, nanosheets and nanosponges) after adsorption and photoexcitation of t-stilbene (t-St). ZSM-5 nanosheets are constituted of lamellar stacking of several nanosheets (20-40 nm) where each nanosheet has a thickness of 2 nm. Nanosponges are composed of ZSM-5 nanocrystals (2-3 nm) separated by mesoporous holes of 5.8 nm facilitating the synthesis of hierachical materials. While the nanosheets show microporosity similar to that observed for the ZSM-5 nanocrystals, the absorption isotherms of the nanosponges show the existence of secondary micropores. After photoirradiation of t-St, UV-vis absorption spectroscopy shows the formation of charge separated states (radical cation and charge transfer complex) in the nanocrystals and in the nanosheets whereas no ionized species is detected in the nanosponges. The radical cation (RC) is stabilized in the nanosheets while it evolves very rapidly towards a Charge Transfer Complex (CTC) in the nanocrocrystals. The particular morphology of the nanosheets and nanosponges is put forward to explain this result since all host materials are of the MFI-type. To investigate ultra-short phenomena in the three nanomaterials, the UV-vis transient spectra were recorded between 2 and 450 mus after photoexcitation by nanosecond laser pulses. In the nanocrystals and nanosheets only the RC is detected whereas CTC formation is not observed. Photoexcitation of t-St in the nanosponges also leads to the formation of a RC but it recombines completely within 70 mus. This suggests the preferential location of t-St in the secondary micropores with pores larger than the micropores of the MFI-type framework and possibly in the mesopores of the nanosponges. |
Isaac, Carole; Confalonieri, Giorgia; Nouali, Habiba; Paillaud, Jean-Louis; Arletti, Rossella; Daou, Jean T; Ryzhikov, Andrey Unusual high-pressure intrusion-extrusion behavior of electrolyte solutions in Mu-26, a pure silica zeolite of topology STF (Article de journal) Microporous and Mesoporous Materials, 298 , p. 110047, 2020. @article{Isaac2020, title = {Unusual high-pressure intrusion-extrusion behavior of electrolyte solutions in Mu-26, a pure silica zeolite of topology STF}, author = { Carole Isaac and Giorgia Confalonieri and Habiba Nouali and Jean-Louis Paillaud and Rossella Arletti and T. Jean Daou and Andrey Ryzhikov}, doi = {10.1016/j.micromeso.2020.110047}, year = {2020}, date = {2020-05-01}, journal = {Microporous and Mesoporous Materials}, volume = {298}, pages = {110047}, publisher = {Elsevier BV}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
Zhou, Ruchun; Jin, Ming; Malval, Jean-Pierre; Pan, Haiyan; Wan, Decheng Bicarbazole-based oxalates as photoinitiating systems for photopolymerization under UV-Vis LEDs (Article de journal) Journal of Polymer Science, 58 (8), p. 1079–1091, 2020. @article{Zhou2020, title = {Bicarbazole-based oxalates as photoinitiating systems for photopolymerization under UV-Vis LEDs}, author = { Ruchun Zhou and Ming Jin and Jean-Pierre Malval and Haiyan Pan and Decheng Wan}, doi = {10.1002/pol.20199298}, year = {2020}, date = {2020-04-01}, journal = {Journal of Polymer Science}, volume = {58}, number = {8}, pages = {1079--1091}, abstract = {Photoinitiators are critical to initiate chain reactions in photopolymerization. For such applications, the absorption of photoinitiator must be compatible with the emission of light sources and enables the fast manufacturing of three-dimensional network or structures. Light-emitting diode (LED) is a new kind of energy-saving and environmental protection light source, exhibiting a substantial response in the near UV and visible range to replace the traditional mercury lamp and other light sources in photopolymerization. Here, we introduce methyl oxalate into bicarbazole chromophore (BiCz). By variation of the single or double substituents in the BiCz, we demonstrate that the absorption spectra can be adjusted and redshift to visible range and show good absorption in the near UV and visible range (365-475 nm). We explore their photochemistry based on experimental results and theoretical calculations and the mechanism of photoreactions have been verified. The super photostability by themselves and good hydrogen abstraction ability from amine co-initiator make them as excellent near UV and visible light active photoinitiators. Critically, the photoinitiation of the free-radical polymerization of acrylate monomers with low content (0.1% concentration) upon LED irradiation at 365-475 nm, exhibits excellent application potential in light curing and other fields.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Photoinitiators are critical to initiate chain reactions in photopolymerization. For such applications, the absorption of photoinitiator must be compatible with the emission of light sources and enables the fast manufacturing of three-dimensional network or structures. Light-emitting diode (LED) is a new kind of energy-saving and environmental protection light source, exhibiting a substantial response in the near UV and visible range to replace the traditional mercury lamp and other light sources in photopolymerization. Here, we introduce methyl oxalate into bicarbazole chromophore (BiCz). By variation of the single or double substituents in the BiCz, we demonstrate that the absorption spectra can be adjusted and redshift to visible range and show good absorption in the near UV and visible range (365-475 nm). We explore their photochemistry based on experimental results and theoretical calculations and the mechanism of photoreactions have been verified. The super photostability by themselves and good hydrogen abstraction ability from amine co-initiator make them as excellent near UV and visible light active photoinitiators. Critically, the photoinitiation of the free-radical polymerization of acrylate monomers with low content (0.1% concentration) upon LED irradiation at 365-475 nm, exhibits excellent application potential in light curing and other fields. |
Jeguirim, Mejdi; Goddard, Mary-Lorene; Tamosiunas, Andrius; Berrich-Betouche, Emna; Azzaz, Ahmed Amine; Praspaliauskas, Marius; Jellali, Salah Olive mill wastewater: From a pollutant to green fuels, agricultural water source and bio-fertilizer. Biofuel production (Article de journal) Renewable Energy, 149 , p. 716–724, 2020. @article{Jeguirim2020, title = {Olive mill wastewater: From a pollutant to green fuels, agricultural water source and bio-fertilizer. Biofuel production}, author = { Mejdi Jeguirim and Mary-Lorene Goddard and Andrius Tamosiunas and Emna Berrich-Betouche and Ahmed Amine Azzaz and Marius Praspaliauskas and Salah Jellali}, doi = {10.1016/j.renene.2019.12.079}, year = {2020}, date = {2020-04-01}, journal = {Renewable Energy}, volume = {149}, pages = {716--724}, abstract = {Olive mill wastewater (OMWW) management is recognized as the major defy that olive oil industry is facing. Recently, we have established an eco-friendly strategy for the OMWW conversion into irrigation water sources, green biofuels and biofertilizers. This work is a part of a series of papers detailing the different steps established in this environmental friendly strategy for OMWW management. It deals with the bio-oil production and characterization during the pyrolysis of OMWW impregnated on olive pomace (OP) in a pyrolyzer pilot. Results show a bio-oil production yield of 36 wt% during the pyrolysis test. This yield could be attributed to the recovery of organic compounds from OMWW through OP impregnation and their conversion to bio-oil. The bio-oil properties show that viscosity and flash point values could reach the European standards. However, the lower heating values (26 MJ/kg) and the acidic character limit its direct use. These values are attributed to the higher water and oxygen contents. The GC/MS analysis confirms these properties showing the presence of phenolic molecules and long chain organic acids. Therefore, OMWW impregnation on OP and pyrolysis could be considered as a promising issue for bio-oil production. However, this bio-oil requires an upgrading step for a better valorization. (C) 2019 Elsevier Ltd. All rights reserved.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Olive mill wastewater (OMWW) management is recognized as the major defy that olive oil industry is facing. Recently, we have established an eco-friendly strategy for the OMWW conversion into irrigation water sources, green biofuels and biofertilizers. This work is a part of a series of papers detailing the different steps established in this environmental friendly strategy for OMWW management. It deals with the bio-oil production and characterization during the pyrolysis of OMWW impregnated on olive pomace (OP) in a pyrolyzer pilot. Results show a bio-oil production yield of 36 wt% during the pyrolysis test. This yield could be attributed to the recovery of organic compounds from OMWW through OP impregnation and their conversion to bio-oil. The bio-oil properties show that viscosity and flash point values could reach the European standards. However, the lower heating values (26 MJ/kg) and the acidic character limit its direct use. These values are attributed to the higher water and oxygen contents. The GC/MS analysis confirms these properties showing the presence of phenolic molecules and long chain organic acids. Therefore, OMWW impregnation on OP and pyrolysis could be considered as a promising issue for bio-oil production. However, this bio-oil requires an upgrading step for a better valorization. (C) 2019 Elsevier Ltd. All rights reserved. |
Battista, Daniele; Luchnikov, Valeriy; Nardinocchi, Paola Shape-shifting of polymer beams and shells due to oil extraction (Article de journal) Extreme Mechanics Letters, 36 , p. 100655, 2020. @article{Battista2020, title = {Shape-shifting of polymer beams and shells due to oil extraction}, author = { Daniele Battista and Valeriy Luchnikov and Paola Nardinocchi}, doi = {10.1016/j.eml.2020.100655}, year = {2020}, date = {2020-04-01}, journal = {Extreme Mechanics Letters}, volume = {36}, pages = {100655}, abstract = {We investigate the morphing of bilayer naturally curved beams and cylindrical shells due to oil extraction from the outer layers. We fabricate bilayer naturally curved beams and cylindrical shells made of PDMS/(PDMS + silicone oil), use the experimental results to validate an explicit formula delivering the change in curvature of the beams, based on the modeling of oil extraction as a bulk contraction. We show as the same model, set up within a 3D context, delivers the morphing of bilayer cylindrical shells and identify potentially interesting results for designing future experiments. In particular, we show as stable states corresponding to the original cylindrical shells can be got in the form of saddle-like shells and cylindrical shells with the axes of principal curvatures switched with respect to the original axes. (c) 2020 Elsevier Ltd. All rights reserved.}, keywords = {}, pubstate = {published}, tppubtype = {article} } We investigate the morphing of bilayer naturally curved beams and cylindrical shells due to oil extraction from the outer layers. We fabricate bilayer naturally curved beams and cylindrical shells made of PDMS/(PDMS + silicone oil), use the experimental results to validate an explicit formula delivering the change in curvature of the beams, based on the modeling of oil extraction as a bulk contraction. We show as the same model, set up within a 3D context, delivers the morphing of bilayer cylindrical shells and identify potentially interesting results for designing future experiments. In particular, we show as stable states corresponding to the original cylindrical shells can be got in the form of saddle-like shells and cylindrical shells with the axes of principal curvatures switched with respect to the original axes. (c) 2020 Elsevier Ltd. All rights reserved. |
Anfar, Zakaria; Zbair, Mohamed; Ahsaine, Hassan Ait; Jada, Amane; Alem, Noureddine El Microwave assisted green synthesis of Fe2O3/biochar for ultrasonic removal of nonsteroidal anti-inflammatory pharmaceuticals (vol 10, pg 11371, 2020) (Article de journal) Rsc Advances, 10 (23), p. 13430–13430, 2020. @article{Anfar2020, title = {Microwave assisted green synthesis of Fe2O3/biochar for ultrasonic removal of nonsteroidal anti-inflammatory pharmaceuticals (vol 10, pg 11371, 2020)}, author = { Zakaria Anfar and Mohamed Zbair and Hassan Ait Ahsaine and Amane Jada and Noureddine El Alem}, doi = {10.1039/d0ra90031a}, year = {2020}, date = {2020-04-01}, journal = {Rsc Advances}, volume = {10}, number = {23}, pages = {13430--13430}, abstract = {Correction for 'Microwave assisted green synthesis of Fe2O3/biochar for ultrasonic removal of nonsteroidal anti-inflammatory pharmaceuticals' by Zakaria Anfar et al., RSC Adv., 2020, 10, 11371-11380.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Correction for 'Microwave assisted green synthesis of Fe2O3/biochar for ultrasonic removal of nonsteroidal anti-inflammatory pharmaceuticals' by Zakaria Anfar et al., RSC Adv., 2020, 10, 11371-11380. |
Abdallah, Mira; Dumur, Frederic; Hijazi, Akram; Rodeghiero, Giacomo; Gualandi, Andrea; Cozzi, Pier G; Lalevee, Jacques Keto-coumarin scaffold for photoinitiators for 3D printing and photocomposites (Article de journal) Journal of Polymer Science, 58 (8), p. 1115–1129, 2020. @article{Abdallah2020a, title = {Keto-coumarin scaffold for photoinitiators for 3D printing and photocomposites}, author = { Mira Abdallah and Frederic Dumur and Akram Hijazi and Giacomo Rodeghiero and Andrea Gualandi and Pier G. Cozzi and Jacques Lalevee}, doi = {10.1002/pol.20190290}, year = {2020}, date = {2020-04-01}, journal = {Journal of Polymer Science}, volume = {58}, number = {8}, pages = {1115--1129}, abstract = {The purposes of this paper are moving toward (a) the development of a new series of photoinitiators (PIs) which are based on the keto-coumarin (KC) core, (b) the introduction of light-emitting diodes (LEDs) as inexpensive and safe sources of irradiation, (c) the study of the photochemical mechanisms through which the new PIs react using different techniques such as Fourier transform infrared, UV-visible or fluorescence spectroscopy, and so on, (d) the use of such compounds (presenting good reactivity and excellent photopolymerization initiating abilities) for two specific and high added value applications: 3D printing (@405 nm) and preparation of thick glass fiber photocomposites with excellent depth of cure, and finally (e) the comparison of the performance of these KC derivatives versus other synthesized coumarin derivatives. In this study, six well-designed KC derivatives (KC-C, KC-D, KC-E, KC-F, KC-G, and KC-H) are examined as high-performance visible-light PIs for the cationic polymerization of epoxides as well as the free-radical polymerization of acrylates upon irradiation with LED@405 nm. Excellent polymerization rates are obtained using two different approaches: a photo-oxidation process in combination with an iodonium (Iod) salt and a photo-reduction process when associated with an amine (N-phenylglycine or ethyl 4-(dimethylamino)benzoate). High final reactive conversions were obtained. A full picture of the involved photochemical mechanisms is provided.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The purposes of this paper are moving toward (a) the development of a new series of photoinitiators (PIs) which are based on the keto-coumarin (KC) core, (b) the introduction of light-emitting diodes (LEDs) as inexpensive and safe sources of irradiation, (c) the study of the photochemical mechanisms through which the new PIs react using different techniques such as Fourier transform infrared, UV-visible or fluorescence spectroscopy, and so on, (d) the use of such compounds (presenting good reactivity and excellent photopolymerization initiating abilities) for two specific and high added value applications: 3D printing (@405 nm) and preparation of thick glass fiber photocomposites with excellent depth of cure, and finally (e) the comparison of the performance of these KC derivatives versus other synthesized coumarin derivatives. In this study, six well-designed KC derivatives (KC-C, KC-D, KC-E, KC-F, KC-G, and KC-H) are examined as high-performance visible-light PIs for the cationic polymerization of epoxides as well as the free-radical polymerization of acrylates upon irradiation with LED@405 nm. Excellent polymerization rates are obtained using two different approaches: a photo-oxidation process in combination with an iodonium (Iod) salt and a photo-reduction process when associated with an amine (N-phenylglycine or ethyl 4-(dimethylamino)benzoate). High final reactive conversions were obtained. A full picture of the involved photochemical mechanisms is provided. |
Platek, Anetta; Nita, Cristina; Ghimbeu, Camelia Matei; Frackowiak, Elzbieta; Fic, Krzysztof Electrochemical capacitors operating in aqueous electrolyte with volumetric characteristics improved by sustainable templating of electrode materials (Article de journal) Electrochimica Acta, 338 , p. 135788, 2020. @article{Platek2020, title = {Electrochemical capacitors operating in aqueous electrolyte with volumetric characteristics improved by sustainable templating of electrode materials}, author = { Anetta Platek and Cristina Nita and Camelia Matei Ghimbeu and Elzbieta Frackowiak and Krzysztof Fic}, doi = {10.1016/j.electacta.2020.135788}, year = {2020}, date = {2020-04-01}, journal = {Electrochimica Acta}, volume = {338}, pages = {135788}, abstract = {Soft- and salt-templating methods have been combined to obtain highly microporous carbon materials with mesopores in the narrow pore size range. Phenolic resin was used as a carbon source, and rubidium and caesium chloride were used as salt-templates, giving a well-developed microporosity with a high specific surface area, whereas a sacrificial triblock polymer Pluronic F-127 (soft-template) induced the mesopores of essential importance for fast access of the electrode surface area for the electrolytic solution. The combination of a high specific surface area (up to 2556 m(2) g(-1)) with a suitable pore size (0.77-0.88 nm) resulted in an excellent performance of the electrochemical capacitor. High specific energies of 16.7 Wh.kg(-1) at 300 W kg(-1) of specific power have been achieved for a CsCl-T-based high-voltage (1.5 V) device with a 0.5 mol.L-1 Li2SO4 electrolytic solution. The improved rate handling was allowed to maintain 10 Wh.kg(-1) of specific energy at 4 kW kg(-1) of specific power. In contrast to the other carbons with well-developed porosities, the material density obtained allowed our device to reach competitive, remarkably higher volumetric characteristics. (C) 2020 The Authors. Published by Elsevier Ltd.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Soft- and salt-templating methods have been combined to obtain highly microporous carbon materials with mesopores in the narrow pore size range. Phenolic resin was used as a carbon source, and rubidium and caesium chloride were used as salt-templates, giving a well-developed microporosity with a high specific surface area, whereas a sacrificial triblock polymer Pluronic F-127 (soft-template) induced the mesopores of essential importance for fast access of the electrode surface area for the electrolytic solution. The combination of a high specific surface area (up to 2556 m(2) g(-1)) with a suitable pore size (0.77-0.88 nm) resulted in an excellent performance of the electrochemical capacitor. High specific energies of 16.7 Wh.kg(-1) at 300 W kg(-1) of specific power have been achieved for a CsCl-T-based high-voltage (1.5 V) device with a 0.5 mol.L-1 Li2SO4 electrolytic solution. The improved rate handling was allowed to maintain 10 Wh.kg(-1) of specific energy at 4 kW kg(-1) of specific power. In contrast to the other carbons with well-developed porosities, the material density obtained allowed our device to reach competitive, remarkably higher volumetric characteristics. (C) 2020 The Authors. Published by Elsevier Ltd. |
Dietlin, Celine; Trinh, Thanh Tam; Schweizer, Stephane; Graff, Bernadette; Morlet-Savary, Fabrice; Noirot, Pierre-Antoine; Lalevee, Jacques New Phosphine Oxides as High Performance Near- UV Type I Photoinitiators of Radical Polymerization. (Article de journal) Molecules (Basel, Switzerland), 25 (7), 2020. @article{Dietlin2020, title = {New Phosphine Oxides as High Performance Near- UV Type I Photoinitiators of Radical Polymerization.}, author = { Celine Dietlin and Thanh Tam Trinh and Stephane Schweizer and Bernadette Graff and Fabrice Morlet-Savary and Pierre-Antoine Noirot and Jacques Lalevee}, doi = {10.3390/molecules25071671}, year = {2020}, date = {2020-04-01}, journal = {Molecules (Basel, Switzerland)}, volume = {25}, number = {7}, abstract = {Carbazole structures are of high interest in photopolymerization due to their enhanced light absorption properties in the near-UV or even visible ranges. Therefore, type I photoinitiators combining the carbazole chromophore to the well-established phosphine-oxides were proposed and studied in this article. The aim of this article was to propose type I photoinitiators that can be more reactive than benchmark phosphine oxides, which are among the more reactive type I photoinitiators for a UV or near-UV light emitting diodes (LED) irradiation. Two molecules were synthesized and their UV-visible light absorption properties as well as the quantum yields of photolysis and photopolymerization performances were measured. Remarkably, the associated absorption was enhanced in the 350-410 nm range compared to benchmark phosphine oxides, and one compound was found to be more reactive in photopolymerization than the commercial photoinitiator TPO-L for an irradiation at 395 nm.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Carbazole structures are of high interest in photopolymerization due to their enhanced light absorption properties in the near-UV or even visible ranges. Therefore, type I photoinitiators combining the carbazole chromophore to the well-established phosphine-oxides were proposed and studied in this article. The aim of this article was to propose type I photoinitiators that can be more reactive than benchmark phosphine oxides, which are among the more reactive type I photoinitiators for a UV or near-UV light emitting diodes (LED) irradiation. Two molecules were synthesized and their UV-visible light absorption properties as well as the quantum yields of photolysis and photopolymerization performances were measured. Remarkably, the associated absorption was enhanced in the 350-410 nm range compared to benchmark phosphine oxides, and one compound was found to be more reactive in photopolymerization than the commercial photoinitiator TPO-L for an irradiation at 395 nm. |
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