Nos publications
Amirou, Siham; Pizzi, Antonio; Delmotte, Luc Investigations of mechanical properties and chemical changes occurring during welding of thermally modified ash wood Article de journal Journal of Adhesion Science and Technology, 34 (1), p. 13–24, 2020. @article{Amirou2020, title = {Investigations of mechanical properties and chemical changes occurring during welding of thermally modified ash wood}, author = { Siham Amirou and Antonio Pizzi and Luc Delmotte}, doi = {10.1080/01694243.2019.1659569}, year = {2020}, date = {2020-01-01}, journal = {Journal of Adhesion Science and Technology}, volume = {34}, number = {1}, pages = {13--24}, abstract = {Heat treatment of wood appears as an ecological and environmentally friendly alternative in the field of wood treatment. Generally, thermal modification increase dimensional stability by reduces of hygroscopicity and water absorption but it makes it difficult to bonding in some application. During welding, changes in the morphological, chemical, and physical properties of the wood cell wall are observed due to the compression and high temperatures produced by welding. Also, the degradation of cell wall in the wood causes some mechanical properties are reduced. This modification appears without any effect on the linear welding of thermal-ash wood. Scanning electron microscopy (SEM) and nuclear magnetic resonance (NMR) were used for evaluation of properties of wood-welding systems and their interactions. The mass spectrometry (MS) analysis was used to identifying the organic degradation products emitted during welding of thermo-ash. The results of experiments show that the use of friction welding for the bonding of thermal ash wood in dry conditions was possible, and we had good results. The best combination was with a welding time of 3.5 s devised to 0.5 s and 3 s and welding pressure 2.5 and 4 MPa, respectively. The result obtained is comparable to the result obtained with EPI adhesives. Welding time greater than 3.5 MPa negatively affects the welding quality and gives low the mechanical strength.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Heat treatment of wood appears as an ecological and environmentally friendly alternative in the field of wood treatment. Generally, thermal modification increase dimensional stability by reduces of hygroscopicity and water absorption but it makes it difficult to bonding in some application. During welding, changes in the morphological, chemical, and physical properties of the wood cell wall are observed due to the compression and high temperatures produced by welding. Also, the degradation of cell wall in the wood causes some mechanical properties are reduced. This modification appears without any effect on the linear welding of thermal-ash wood. Scanning electron microscopy (SEM) and nuclear magnetic resonance (NMR) were used for evaluation of properties of wood-welding systems and their interactions. The mass spectrometry (MS) analysis was used to identifying the organic degradation products emitted during welding of thermo-ash. The results of experiments show that the use of friction welding for the bonding of thermal ash wood in dry conditions was possible, and we had good results. The best combination was with a welding time of 3.5 s devised to 0.5 s and 3 s and welding pressure 2.5 and 4 MPa, respectively. The result obtained is comparable to the result obtained with EPI adhesives. Welding time greater than 3.5 MPa negatively affects the welding quality and gives low the mechanical strength. |
Khiari, Besma; Ghouma, Imen; Ferjani, Amel Ibn; Azzaz, Ahmed Amine; Jellali, Salah; Limousy, Lionel; Jeguirim, Mejdi Kenaf stems: Thermal characterization and conversion for biofuel and biochar production Article de journal Fuel, 262 , p. UNSP 116654, 2020. @article{Khiari2020, title = {Kenaf stems: Thermal characterization and conversion for biofuel and biochar production}, author = { Besma Khiari and Imen Ghouma and Amel Ibn Ferjani and Ahmed Amine Azzaz and Salah Jellali and Lionel Limousy and Mejdi Jeguirim}, doi = {10.1016/j.fuel.2019.116654}, year = {2020}, date = {2020-01-01}, journal = {Fuel}, volume = {262}, pages = {UNSP 116654}, abstract = {Kenaf stems are characterized in this present investigation in order to assess their suitability in energy recovery through a pyrolysis process and to identify sustainable applications of the generated biochar. In particular, the raw biomass properties are analyzed using numerous analytical techniques such as thermogravimetric analyses (TGA/DTG), X-Ray Fluorescence (XRF) and Scanning Electronic Microscopy (SEM). First, the thermogravimetric analyses monitor the pyrolysis parameters, control the proportion of its outputs and allow to extract the kinetic parameters. The latter is determined using Friedman, Flynn-Wall-Ozawa (FWO) and Kissinger-Akahira-Sunose (KAS) models. In a second step, Kenaf derived chars are produced at different pyrolysis temperatures and their physicochemical, morphological, textural and structural properties are determined using different techniques such as CO2 adsorption, Raman Spectroscopy, and DRIFT Spectroscopy. The main results confirm the Kenaf potential for energy applications as its thermal properties are more interesting compared to other usual crops. The Kenaf stem derived char is also very promising for pollutants removal or gas storage as its surface area as well as its microporous structure are interestingly developed when increasing the pyrolysis temperature. Kenaf char could be also chemically or physically activated in order to be used for pollutants removal from gaseous and aqueous effluents. Finally, the XRF analysis indicated that contents in K and P elements are high. Ca and Mg are also major mineral species in the char. These contents indicate that Kenaf derived char could be also suitable for agricultural soil amendments.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Kenaf stems are characterized in this present investigation in order to assess their suitability in energy recovery through a pyrolysis process and to identify sustainable applications of the generated biochar. In particular, the raw biomass properties are analyzed using numerous analytical techniques such as thermogravimetric analyses (TGA/DTG), X-Ray Fluorescence (XRF) and Scanning Electronic Microscopy (SEM). First, the thermogravimetric analyses monitor the pyrolysis parameters, control the proportion of its outputs and allow to extract the kinetic parameters. The latter is determined using Friedman, Flynn-Wall-Ozawa (FWO) and Kissinger-Akahira-Sunose (KAS) models. In a second step, Kenaf derived chars are produced at different pyrolysis temperatures and their physicochemical, morphological, textural and structural properties are determined using different techniques such as CO2 adsorption, Raman Spectroscopy, and DRIFT Spectroscopy. The main results confirm the Kenaf potential for energy applications as its thermal properties are more interesting compared to other usual crops. The Kenaf stem derived char is also very promising for pollutants removal or gas storage as its surface area as well as its microporous structure are interestingly developed when increasing the pyrolysis temperature. Kenaf char could be also chemically or physically activated in order to be used for pollutants removal from gaseous and aqueous effluents. Finally, the XRF analysis indicated that contents in K and P elements are high. Ca and Mg are also major mineral species in the char. These contents indicate that Kenaf derived char could be also suitable for agricultural soil amendments. |
Bennici, Simona; Polimann, Teo; Ondarts, Michel; Gonze, Evelyne; Vaulot, Cyril; Pierres, Nolwenn Le Long-term impact of air pollutants on thermochemical heat storage materials Article de journal Renewable & Sustainable Energy Reviews, 117 , p. 109473, 2020. @article{Bennici2020, title = {Long-term impact of air pollutants on thermochemical heat storage materials}, author = { Simona Bennici and Teo Polimann and Michel Ondarts and Evelyne Gonze and Cyril Vaulot and Nolwenn Le Pierres}, doi = {10.1016/j.rser.2019.109473}, year = {2020}, date = {2020-01-01}, journal = {Renewable & Sustainable Energy Reviews}, volume = {117}, pages = {109473}, abstract = {Heating of buildings is a highly energy-demanding task. Therefore, improving energy management is crucial for more environmentally friendly development of future constructions, and the use of thermochemical heat storage technologies in solid materials is one of the most promising solutions. Nevertheless, certain drawbacks such as the impact of air pollutants on the long term durability of thermochemical heat storage materials (ageing up to 30 years) need to be studied to implement installations. In certain thermochemical heat storage systems, air passes through porous materials to carry water and heat, and the air's pollutants can interact with the solid material, thus decreasing its storage capacity. In the present work, adsorption tests were performed (under dynamic conditions) on zeolite-base materials, using different model molecules (i.e. toluene, styrene and hexaldehyde) representative of air pollutants. Strong competition between the adsorption of pollutants and water on the storage material was demonstrated. Water molecules were able to displace the molecules of pollutants, previously adsorbed on the material surface, thus delaying the saturation of the material and extending its life. Nevertheless, a lowering of the water adsorption and heat storage capacity was measured for a high number of cycles. The cycled materials have been thoroughly characterised in their physicochemical properties to identify the modifications of the materials (i.e., dealumination) and correlate them with the heat storage capacity. The impact of pollutants was demonstrated to be stronger on the pure zeolite, while the salt present on the MgSO4/13x composite seems to protect the material surface from the pollutant effect.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Heating of buildings is a highly energy-demanding task. Therefore, improving energy management is crucial for more environmentally friendly development of future constructions, and the use of thermochemical heat storage technologies in solid materials is one of the most promising solutions. Nevertheless, certain drawbacks such as the impact of air pollutants on the long term durability of thermochemical heat storage materials (ageing up to 30 years) need to be studied to implement installations. In certain thermochemical heat storage systems, air passes through porous materials to carry water and heat, and the air's pollutants can interact with the solid material, thus decreasing its storage capacity. In the present work, adsorption tests were performed (under dynamic conditions) on zeolite-base materials, using different model molecules (i.e. toluene, styrene and hexaldehyde) representative of air pollutants. Strong competition between the adsorption of pollutants and water on the storage material was demonstrated. Water molecules were able to displace the molecules of pollutants, previously adsorbed on the material surface, thus delaying the saturation of the material and extending its life. Nevertheless, a lowering of the water adsorption and heat storage capacity was measured for a high number of cycles. The cycled materials have been thoroughly characterised in their physicochemical properties to identify the modifications of the materials (i.e., dealumination) and correlate them with the heat storage capacity. The impact of pollutants was demonstrated to be stronger on the pure zeolite, while the salt present on the MgSO4/13x composite seems to protect the material surface from the pollutant effect. |
Huve, Joffrey; Daou, Jean T; Nouali, Habiba; Patarin, Joel; Ryzhikov, Andrey The effect of nanostructures on high pressure intrusion-extrusion of water and electrolyte solutions in hierarchical nanoboxes of silicalite-1 Article de journal New Journal of Chemistry, 44 (1), p. 273–281, 2020. @article{Huve2020, title = {The effect of nanostructures on high pressure intrusion-extrusion of water and electrolyte solutions in hierarchical nanoboxes of silicalite-1}, author = { Joffrey Huve and T. Jean Daou and Habiba Nouali and Joel Patarin and Andrey Ryzhikov}, doi = {10.1039/c9nj01891c}, year = {2020}, date = {2020-01-01}, journal = {New Journal of Chemistry}, volume = {44}, number = {1}, pages = {273--281}, abstract = {This study of high pressure intrusion-extrusion of water and 20 M LiCl solution in silicalite-1 nanoboxes demonstrates how nanostructures can determine the properties of materials. The drastic effect of the presence of cavities on the intrusion-extrusion behavior and characteristics has been observed, particularly, in the case of LiCl aqueous solution. The nanoboxes demonstrate a combination of bumper and spring behavior in the first intrusion-extrusion cycle. The intrusion of 20 M LiCl solution is only partially reversible and takes place in two clearly marked steps, whereas only one intrusion step with a fully reversible spring behavior is observed for the micro- and nanocrystals. The first step, with an intruded volume of 0.07 mL g(-1) and an intruded pressure of 98 MPa, is irreversible and corresponds probably to the filling of mesoporous cavities, and the second one, with an intruded volume of 0.08 mL g(-1) and an intrusion pressure of 273 MPa, is fully reversible and related to the filling of the micropores of silicalite-1 walls. The filling of the nanocavities occurs probably through small mesoporous cracks in the nanobox walls. The characterization by structural and physicochemical methods shows that the dissolution-recrystallization process leads to the formation of a MFI structure with lower content of silanol defects in comparison with initial nanocrystals explaining the steeper slope of the intrusion step and the higher intrusion pressure observed for the "nanobox-H2O" and "nanobox-20 M LiCl" systems.}, keywords = {}, pubstate = {published}, tppubtype = {article} } This study of high pressure intrusion-extrusion of water and 20 M LiCl solution in silicalite-1 nanoboxes demonstrates how nanostructures can determine the properties of materials. The drastic effect of the presence of cavities on the intrusion-extrusion behavior and characteristics has been observed, particularly, in the case of LiCl aqueous solution. The nanoboxes demonstrate a combination of bumper and spring behavior in the first intrusion-extrusion cycle. The intrusion of 20 M LiCl solution is only partially reversible and takes place in two clearly marked steps, whereas only one intrusion step with a fully reversible spring behavior is observed for the micro- and nanocrystals. The first step, with an intruded volume of 0.07 mL g(-1) and an intruded pressure of 98 MPa, is irreversible and corresponds probably to the filling of mesoporous cavities, and the second one, with an intruded volume of 0.08 mL g(-1) and an intrusion pressure of 273 MPa, is fully reversible and related to the filling of the micropores of silicalite-1 walls. The filling of the nanocavities occurs probably through small mesoporous cracks in the nanobox walls. The characterization by structural and physicochemical methods shows that the dissolution-recrystallization process leads to the formation of a MFI structure with lower content of silanol defects in comparison with initial nanocrystals explaining the steeper slope of the intrusion step and the higher intrusion pressure observed for the "nanobox-H2O" and "nanobox-20 M LiCl" systems. |
Sciacca, Davide; Peric, Nemanja; Berthe, Maxime; Biadala, Louis; Pirri, Carmelo; Derivaz, Mickael; Massara, Natalia; Diener, Pascale; Grandidier, Bruno Account of the diversity of tunneling spectra at the germanene/Al(111) interface Article de journal Journal of Physics-condensed Matter, 32 (5), p. 055002, 2020. @article{Sciacca2020, title = {Account of the diversity of tunneling spectra at the germanene/Al(111) interface}, author = { Davide Sciacca and Nemanja Peric and Maxime Berthe and Louis Biadala and Carmelo Pirri and Mickael Derivaz and Natalia Massara and Pascale Diener and Bruno Grandidier}, doi = {10.1088/1361-648X/ab4d15}, year = {2020}, date = {2020-01-01}, journal = {Journal of Physics-condensed Matter}, volume = {32}, number = {5}, pages = {055002}, abstract = {Despite the wealth of tunneling spectroscopic studies performed on silicene and germanene, the observation of a well-defined Dirac cone in these materials remains elusive. Here, we study germanene grown on Al(1 1 1) at submonolayer coverages with low temperature scanning tunneling spectroscopy. We show that the tunnelling spectra of the Al(1 1 1) surface and the germanene nanosheets are identical. They exhibit a clear metallic behaviour at the beginning of the experiments, that highlights the strong electronic coupling between the adlayer and the substrate. Over the course of the experiments, the spectra deviate from this initial behaviour, although consecutive spectra measured on the Al(1 1 1) surface and germanene nanosheets are still similar. This spectral diversity is explained by modifications of the tip apex, that arise from the erratic manipulation of the germanium adlayer. The origin of the characteristic features such as a wide band gap, coherence-like peaks or zero-bias anomalies are tentatively discussed in light of the physical properties of Ge and AlGe alloy clusters, that are likely to adsorb at the tip apex.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Despite the wealth of tunneling spectroscopic studies performed on silicene and germanene, the observation of a well-defined Dirac cone in these materials remains elusive. Here, we study germanene grown on Al(1 1 1) at submonolayer coverages with low temperature scanning tunneling spectroscopy. We show that the tunnelling spectra of the Al(1 1 1) surface and the germanene nanosheets are identical. They exhibit a clear metallic behaviour at the beginning of the experiments, that highlights the strong electronic coupling between the adlayer and the substrate. Over the course of the experiments, the spectra deviate from this initial behaviour, although consecutive spectra measured on the Al(1 1 1) surface and germanene nanosheets are still similar. This spectral diversity is explained by modifications of the tip apex, that arise from the erratic manipulation of the germanium adlayer. The origin of the characteristic features such as a wide band gap, coherence-like peaks or zero-bias anomalies are tentatively discussed in light of the physical properties of Ge and AlGe alloy clusters, that are likely to adsorb at the tip apex. |
Oliveira, Larissa V F; Bennici, Simona; Josien, Ludovic; Limousy, Lionel; Bizeto, Marcos A; Camilo, Fernanda F Free-standing cellulose film containing manganese dioxide nanoparticles and its use in discoloration of indigo carmine dye Article de journal Carbohydrate Polymers, 230 , p. 115621, 2020. @article{Oliveira2020, title = {Free-standing cellulose film containing manganese dioxide nanoparticles and its use in discoloration of indigo carmine dye}, author = { Larissa V. F. Oliveira and Simona Bennici and Ludovic Josien and Lionel Limousy and Marcos A. Bizeto and Fernanda F. Camilo}, doi = {10.1016/j.carbpol.2019.115621}, year = {2020}, date = {2020-01-01}, journal = {Carbohydrate Polymers}, volume = {230}, pages = {115621}, abstract = {In this study, we report the production of a free-standing film of non-modified cellulose impregnated with 12 wt % of MnO2 nanoparticles with less than 100 nm in size. The method here described can be applied to the immobilization of different types of nanoparticles. The film was prepared by dissolving microcrystalline cellulose in an ionic liquid followed by its regeneration by adding water to the former solution. Then, the wet film was impregnated with the nanoparticles by dipping it in a MnO2 dispersion. Electron microscopy images revealed manganese dioxide nanoparticles distributed not only at the film surface but also in its interior. The cellulose film impregnated with MnO2 nanoparticles was capable of efficiently discolouring an Indigo Carmine dye solution in 25 min upon ambient light. The film was easily removed from the dye solution and repeatedly reused for at least 10 times without losing its discolouring efficiency.}, keywords = {}, pubstate = {published}, tppubtype = {article} } In this study, we report the production of a free-standing film of non-modified cellulose impregnated with 12 wt % of MnO2 nanoparticles with less than 100 nm in size. The method here described can be applied to the immobilization of different types of nanoparticles. The film was prepared by dissolving microcrystalline cellulose in an ionic liquid followed by its regeneration by adding water to the former solution. Then, the wet film was impregnated with the nanoparticles by dipping it in a MnO2 dispersion. Electron microscopy images revealed manganese dioxide nanoparticles distributed not only at the film surface but also in its interior. The cellulose film impregnated with MnO2 nanoparticles was capable of efficiently discolouring an Indigo Carmine dye solution in 25 min upon ambient light. The film was easily removed from the dye solution and repeatedly reused for at least 10 times without losing its discolouring efficiency. |
Berger, M; Dorge, S; Nouali, H; Habermacher, D; Fiani, E; Vierling, M; Moliere, M; Brilhac, J F; Patarin, J Desulfurization process: understanding of the behaviour of the CuO/SBA-15 type SOx adsorbent in the presence of NO/NO2 and CO/CO2 flue gas environmental pollutants Article de journal Chemical Engineering Journal, 384 , p. 123318, 2020. @article{Berger2020, title = {Desulfurization process: understanding of the behaviour of the CuO/SBA-15 type SOx adsorbent in the presence of NO/NO2 and CO/CO2 flue gas environmental pollutants}, author = { M. Berger and S. Dorge and H. Nouali and D. Habermacher and E. Fiani and M. Vierling and M. Moliere and J. F. Brilhac and J. Patarin}, doi = {10.1016/j.cej.2019.123318}, year = {2020}, date = {2020-01-01}, journal = {Chemical Engineering Journal}, volume = {384}, pages = {123318}, abstract = {SOx (i.e. SO2 and SO3) compounds are known to be a major source of atmospheric pollution and to be responsible of adverse effects on the human health and on the environment. To reduce the SOx emissions, numerous abatement technologies were developed and applied. Nowadays, the most attractive one seems to be the process that use a regenerable SOx adsorbent. In this respect, a CuO (15 wt.%)/SBA-15 regenerable type SOx adsorbent has been developed. Under standard conditions (a gaseous mixture of N-2, SO2 and O-2), the adsorbent exhibits a stable adsorption capacity around 50 mg(SO2)/g(ads) along 10 cycles at 400 degrees C (for a 75 ppm of SO 2 exhaust concentration). The main aim of this work is to study the impact of various regulated pollutants such as CO, CO 2 , NO and NO2 on the SO2 adsorption capacity of the CuO (15 wt.%)/SBA-15 adsorbent. In the presence of CO and CO2, the SO2 adsorption performance of the CuO/SBA adsorbent is similar to the one observed under standard conditions. On the other hand, under NO and NO2 atmosphere, the dynamic and total adsorption capacities of the adsorbent are enhanced up to 25% and no deactivation occurs along the cycles. The increase may be related with the synergetic effect between NO2 and SO2 towards the sulphate formation. The CuO/SBA-15 adsorbent before and after multicycle SO2 adsorption in the presence of regulated pollutants and regeneration under 0.5 vol.% of H-2 have been characterized by XRD and N-2 physisorption. No significant structural and textural change is observed compared to the CuO/SBA-SO2 adsorbent.}, keywords = {}, pubstate = {published}, tppubtype = {article} } SOx (i.e. SO2 and SO3) compounds are known to be a major source of atmospheric pollution and to be responsible of adverse effects on the human health and on the environment. To reduce the SOx emissions, numerous abatement technologies were developed and applied. Nowadays, the most attractive one seems to be the process that use a regenerable SOx adsorbent. In this respect, a CuO (15 wt.%)/SBA-15 regenerable type SOx adsorbent has been developed. Under standard conditions (a gaseous mixture of N-2, SO2 and O-2), the adsorbent exhibits a stable adsorption capacity around 50 mg(SO2)/g(ads) along 10 cycles at 400 degrees C (for a 75 ppm of SO 2 exhaust concentration). The main aim of this work is to study the impact of various regulated pollutants such as CO, CO 2 , NO and NO2 on the SO2 adsorption capacity of the CuO (15 wt.%)/SBA-15 adsorbent. In the presence of CO and CO2, the SO2 adsorption performance of the CuO/SBA adsorbent is similar to the one observed under standard conditions. On the other hand, under NO and NO2 atmosphere, the dynamic and total adsorption capacities of the adsorbent are enhanced up to 25% and no deactivation occurs along the cycles. The increase may be related with the synergetic effect between NO2 and SO2 towards the sulphate formation. The CuO/SBA-15 adsorbent before and after multicycle SO2 adsorption in the presence of regulated pollutants and regeneration under 0.5 vol.% of H-2 have been characterized by XRD and N-2 physisorption. No significant structural and textural change is observed compared to the CuO/SBA-SO2 adsorbent. |
Paillaud, Jean-Louis; Gies, Hermann Editorial Article de journal Microporous and Mesoporous Materials, 291 , p. UNSP 109706, 2020. @article{Paillaud2020, title = {Editorial}, author = { Jean-Louis Paillaud and Hermann Gies}, doi = {10.1016/j.micromeso.2019.109706}, year = {2020}, date = {2020-01-01}, journal = {Microporous and Mesoporous Materials}, volume = {291}, pages = {UNSP 109706}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
Maschowski, Christoph; Kruspan, Peter; Garra, Patxi; Arif, Ali Talib; Trouve, Gwenaelle; Giere, Reto Physicochemical and mineralogical characterization of biomass ash from different power plants in the Upper Rhine Region Article de journal Fuel, 258 , p. UNSP 116020, 2019. @article{Maschowski2019, title = {Physicochemical and mineralogical characterization of biomass ash from different power plants in the Upper Rhine Region}, author = { Christoph Maschowski and Peter Kruspan and Patxi Garra and Ali Talib Arif and Gwenaelle Trouve and Reto Giere}, doi = {10.1016/j.fuel.2019.116020}, year = {2019}, date = {2019-12-01}, journal = {Fuel}, volume = {258}, pages = {UNSP 116020}, abstract = {Bottom and fly ash samples from six biomass power plants with different power scales and various flue gas treatment strategies were collected and analyzed in regard to their mineralogical composition, and their bulk major and trace element contents, all of which are of concern for regulations on biomass ash for further utilization. Furthermore, individual ash particles were investigated by scanning electron microscopy to characterize their physicochemical microstructures. Thermal behavior of wood-pellet ash, i.e. decomposition processes and mineral transformations during combustion, was indicated by thermogravimetric analysis and X-ray diffraction. Results reveal extensive variation of physicochemical features across the different ash types: wood-chip fly ash from electrostatic precipitators mainly consisted of water-soluble salts, whereas wood-chip fly ash from cyclones contained predominantly cenospheres (hollow spherical fly ash particles) and higher heavy metal concentrations. In addition, the fuel type and admixture had influences on ash compositions; some fuels like Miscanthus straw require a liming agent such as calcium hydroxide to be admixed to prevent fouling, which is then predominantly found in the ash. Furthermore, boiler size had an influence on fly ash composition. Cadmium concentrations were elevated in some fly ash samples at levels of concern for further utilization, whereas concentrations of troublesome Cr(VI) were below the detection limit for all investigated ash samples. Other contaminating elements such as Ni, Pb and Zn were variable but below limit values. Results clearly show that the nature of biomass ash calls for careful analyses prior to further application as, e.g., cement clinker replacement material.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Bottom and fly ash samples from six biomass power plants with different power scales and various flue gas treatment strategies were collected and analyzed in regard to their mineralogical composition, and their bulk major and trace element contents, all of which are of concern for regulations on biomass ash for further utilization. Furthermore, individual ash particles were investigated by scanning electron microscopy to characterize their physicochemical microstructures. Thermal behavior of wood-pellet ash, i.e. decomposition processes and mineral transformations during combustion, was indicated by thermogravimetric analysis and X-ray diffraction. Results reveal extensive variation of physicochemical features across the different ash types: wood-chip fly ash from electrostatic precipitators mainly consisted of water-soluble salts, whereas wood-chip fly ash from cyclones contained predominantly cenospheres (hollow spherical fly ash particles) and higher heavy metal concentrations. In addition, the fuel type and admixture had influences on ash compositions; some fuels like Miscanthus straw require a liming agent such as calcium hydroxide to be admixed to prevent fouling, which is then predominantly found in the ash. Furthermore, boiler size had an influence on fly ash composition. Cadmium concentrations were elevated in some fly ash samples at levels of concern for further utilization, whereas concentrations of troublesome Cr(VI) were below the detection limit for all investigated ash samples. Other contaminating elements such as Ni, Pb and Zn were variable but below limit values. Results clearly show that the nature of biomass ash calls for careful analyses prior to further application as, e.g., cement clinker replacement material. |
Ghimbeu, Camelia Matei; Zhang, Biao; de Yuso, Alicia Martinez; Rety, Benedicte; Tarascon, Jean-Marie Valorizing low cost and renewable lignin as hard carbon for Na-ion batteries: Impact of lignin grade Article de journal Carbon, 153 , p. 634–647, 2019. @article{Ghimbeu2019, title = {Valorizing low cost and renewable lignin as hard carbon for Na-ion batteries: Impact of lignin grade}, author = { Camelia Matei Ghimbeu and Biao Zhang and Alicia Martinez de Yuso and Benedicte Rety and Jean-Marie Tarascon}, doi = {10.1016/j.carbon.2019.07.026}, year = {2019}, date = {2019-11-01}, journal = {Carbon}, volume = {153}, pages = {634--647}, abstract = {Lignin, the second most abundant biopolymer and rich in aromatic entities, is a by-product of paper industry and mainly burned to produce energy. Its commercialization for high-value added products remains largely unexplored today. Herein, we explored the preparation of hard carbon anodes for sodium-ion batteries using the two most common lignin grades, i.e, lignin kraft and lignin sulphonate. The lignin kraft hard carbon (LK-HC) shows small specific surface area (1.8 m(2)g(-1)) and a dense random like morphology while the latter lignin sulphonate hard carbon (LS-HC) presents a high surface area (180 m(2)g(-1)) and spherical particles containing macropores. Their electrochemical performances vs. Na+ revealed a steady capacity of 181 mAh g(-1) over cycling for LK-HC, as compared to a capacity of 205 mAh g(-1) for LS-HC which fades after 30 cycles due to an impurity-driven growth of a blocking solid electrolyte interphase (SEI). To circumvent this issue, an efficient washing procedure was successfully implemented enabling to obtain (LSW-HC) carbons which deliver a high and stable capacity (284 mAh g(-1)) along efficiency (78.1%). (C) 2019 Elsevier Ltd. All rights reserved.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Lignin, the second most abundant biopolymer and rich in aromatic entities, is a by-product of paper industry and mainly burned to produce energy. Its commercialization for high-value added products remains largely unexplored today. Herein, we explored the preparation of hard carbon anodes for sodium-ion batteries using the two most common lignin grades, i.e, lignin kraft and lignin sulphonate. The lignin kraft hard carbon (LK-HC) shows small specific surface area (1.8 m(2)g(-1)) and a dense random like morphology while the latter lignin sulphonate hard carbon (LS-HC) presents a high surface area (180 m(2)g(-1)) and spherical particles containing macropores. Their electrochemical performances vs. Na+ revealed a steady capacity of 181 mAh g(-1) over cycling for LK-HC, as compared to a capacity of 205 mAh g(-1) for LS-HC which fades after 30 cycles due to an impurity-driven growth of a blocking solid electrolyte interphase (SEI). To circumvent this issue, an efficient washing procedure was successfully implemented enabling to obtain (LSW-HC) carbons which deliver a high and stable capacity (284 mAh g(-1)) along efficiency (78.1%). (C) 2019 Elsevier Ltd. All rights reserved. |
Ng, Eng-Poh; Abdullahi, Haruna; Wong, Ka-Lun; Gines-Molina, Maria Jose; Maireles-Torres, Pedro; Rigolet, Severinne; Daou, Jean T; Chia, Stephen; Lee, Hooi Ling Ultrasmall Cs-AlMCM-41 basic catalysts: Effects of aluminum addition on their physico-chemical and catalytic properties Article de journal Microporous and Mesoporous Materials, 288 , p. UNSP 109599, 2019. @article{Ng2019f, title = {Ultrasmall Cs-AlMCM-41 basic catalysts: Effects of aluminum addition on their physico-chemical and catalytic properties}, author = { Eng-Poh Ng and Haruna Abdullahi and Ka-Lun Wong and Maria Jose Gines-Molina and Pedro Maireles-Torres and Severinne Rigolet and T. Jean Daou and Stephen Chia and Hooi Ling Lee}, doi = {10.1016/j.micromeso.2019.109599}, year = {2019}, date = {2019-11-01}, journal = {Microporous and Mesoporous Materials}, volume = {288}, pages = {UNSP 109599}, abstract = {In this study, ultra-small MCM-41 mesoporous solids (< 30 nm) were synthesized using colloidal silica and cesium hydroxide as cheap silica source and mineralize; respectively. Four samples with a SiO2/Al2O3 ratio of 5, 20, 30 and infinity (designated as CsM-5, CsM-20, CsM-30 and CsM-infinity, respectively) have been prepared. The effects of SiO2/Al2O3 ratio on the formation, physico-chemical and catalytic properties of CsMCM-41 nanoparticles were studied. The results show that incorporation of high content of Al atoms into the framework reduces the ordering of the mesostructure, and hence the porosity of the solids decreases. By using CsOH as mineralizer, the morphology and the size of CsMCM-41 were also tuned from 3-D nanospheres (CsM-5: 29 nm and CsM-20: 27 nm) to hollow nanospheres with very thin walls (CsM-30: 25 nm, CsM-infinity: 20 nm) when Al content was decreased. The basicity of CsMCM-41 nanoparticles was also affected by the AI and Cs contents. Hence, their catalytic behavior in the base-catalyzed reactions such as aldol condensation of heptanal with benzaldehyde, and Perkin condensation of benzaldehyde with acetic anhydride was evaluated under microwave heating conditions. CsM-20 displays the best catalytic activities among the samples studied, achieving 87.2% conversion and 78.4% selectivity to jasminaldehyde under optimum reaction conditions, while it also shows comparable catalytic performance as NaOH homogeneous catalyst in the Perkin condensation reaction under non-microwave instant heating conditions.}, keywords = {}, pubstate = {published}, tppubtype = {article} } In this study, ultra-small MCM-41 mesoporous solids (< 30 nm) were synthesized using colloidal silica and cesium hydroxide as cheap silica source and mineralize; respectively. Four samples with a SiO2/Al2O3 ratio of 5, 20, 30 and infinity (designated as CsM-5, CsM-20, CsM-30 and CsM-infinity, respectively) have been prepared. The effects of SiO2/Al2O3 ratio on the formation, physico-chemical and catalytic properties of CsMCM-41 nanoparticles were studied. The results show that incorporation of high content of Al atoms into the framework reduces the ordering of the mesostructure, and hence the porosity of the solids decreases. By using CsOH as mineralizer, the morphology and the size of CsMCM-41 were also tuned from 3-D nanospheres (CsM-5: 29 nm and CsM-20: 27 nm) to hollow nanospheres with very thin walls (CsM-30: 25 nm, CsM-infinity: 20 nm) when Al content was decreased. The basicity of CsMCM-41 nanoparticles was also affected by the AI and Cs contents. Hence, their catalytic behavior in the base-catalyzed reactions such as aldol condensation of heptanal with benzaldehyde, and Perkin condensation of benzaldehyde with acetic anhydride was evaluated under microwave heating conditions. CsM-20 displays the best catalytic activities among the samples studied, achieving 87.2% conversion and 78.4% selectivity to jasminaldehyde under optimum reaction conditions, while it also shows comparable catalytic performance as NaOH homogeneous catalyst in the Perkin condensation reaction under non-microwave instant heating conditions. |
Pavlova, Elizaveta R; Bagrov, Dmitry V; Monakhova, Kristina Z; Piryazev, Alexey A; Sokolova, Anastasia I; Ivanov, Dimitri A; Klinov, Dmitry V Tuning the properties of electrospun polylactide mats by ethanol treatment Article de journal Materials & Design, 181 , p. UNSP 108061, 2019. @article{Pavlova2019, title = {Tuning the properties of electrospun polylactide mats by ethanol treatment}, author = { Elizaveta R. Pavlova and Dmitry V. Bagrov and Kristina Z. Monakhova and Alexey A. Piryazev and Anastasia I. Sokolova and Dimitri A. Ivanov and Dmitry V. Klinov}, doi = {10.1016/j.matdes.2019.108061}, year = {2019}, date = {2019-11-01}, journal = {Materials & Design}, volume = {181}, pages = {UNSP 108061}, abstract = {In the present work, we analyzed the changes in structure and mechanical properties of electrospun PLA mats induced by ethanol treatment. The amorphous PLA mats gained elasticity when immersed into ethanol (the elongation at break increased from epsilon similar to 50% in air to epsilon similar to 280% in ethanol) and partly retained it after drying (epsilon similar to 110%). At the nanoscale, the ethanol treatment caused crimping of the fibers without crystallinity increase. Stretching of the electrospun mats in ethanol caused high alignment of the fibers (geometrical orientation factor f = 0.92) without the need for a special collector electrode such as a pair of blades, which yielded mats with geometrical orientation factor f = 0.71. The aligned mats prepared by stretching in ethanol caused contact guidance of HaCaT human keratinocytes and did not taint viability and proliferation rate of cells in comparison with the non-aligned ones. Our research demonstrates the tuning of electrospun mats properties by post-treatment without any modification of the chemical structure. (C) 2019 The Author(s). Published by Elsevier Ltd.}, keywords = {}, pubstate = {published}, tppubtype = {article} } In the present work, we analyzed the changes in structure and mechanical properties of electrospun PLA mats induced by ethanol treatment. The amorphous PLA mats gained elasticity when immersed into ethanol (the elongation at break increased from epsilon similar to 50% in air to epsilon similar to 280% in ethanol) and partly retained it after drying (epsilon similar to 110%). At the nanoscale, the ethanol treatment caused crimping of the fibers without crystallinity increase. Stretching of the electrospun mats in ethanol caused high alignment of the fibers (geometrical orientation factor f = 0.92) without the need for a special collector electrode such as a pair of blades, which yielded mats with geometrical orientation factor f = 0.71. The aligned mats prepared by stretching in ethanol caused contact guidance of HaCaT human keratinocytes and did not taint viability and proliferation rate of cells in comparison with the non-aligned ones. Our research demonstrates the tuning of electrospun mats properties by post-treatment without any modification of the chemical structure. (C) 2019 The Author(s). Published by Elsevier Ltd. |
Vigliaturo, Ruggero; Kehrli, Damaris; Garra, Patxi; Dieterlen, Alain; Trouve, Gwenaelle; Dietze, Volker; Wilson, Jonathan P; Giere, Reto Opaline phytoliths in Miscanthus sinensis and its cyclone ash from a biomass-combustion facility Article de journal Industrial Crops and Products, 139 , p. UNSP 111539, 2019. @article{Vigliaturo2019, title = {Opaline phytoliths in Miscanthus sinensis and its cyclone ash from a biomass-combustion facility}, author = { Ruggero Vigliaturo and Damaris Kehrli and Patxi Garra and Alain Dieterlen and Gwenaelle Trouve and Volker Dietze and Jonathan P. Wilson and Reto Giere}, doi = {10.1016/j.indcrop.2019.111539}, year = {2019}, date = {2019-11-01}, journal = {Industrial Crops and Products}, volume = {139}, pages = {UNSP 111539}, abstract = {Classifying biofuel feedstock crops on the basis of their inorganic constituents is needed to evaluate the critical role these components play during combustion and, later, when the ashes are used as fertilizer or as secondary raw material. Fluorescent and white-light microscopy, in combination with environmental scanning electron microscopy and energy-dispersive X-ray spectroscopy, was used to characterize phytoliths in Miscanthus sinensis, its dry extracts, and in the cyclone ash produced by the semi-industrial (400 kW) burning of this energy crop. The results show that the phytoliths are made of opal, SiO2 center dot n(H2O). X-ray powder diffraction data document that the SiO2-rich (31.7 wt%) cyclone ash consists of nearly 83 wt% amorphous material, which reflects the abundance of phytoliths in the studied materials. The cyclone ash also contains high amounts of some heavy metals, which suggests that Miscanthus sinensis is suitable for bioremediation of contaminated soils.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Classifying biofuel feedstock crops on the basis of their inorganic constituents is needed to evaluate the critical role these components play during combustion and, later, when the ashes are used as fertilizer or as secondary raw material. Fluorescent and white-light microscopy, in combination with environmental scanning electron microscopy and energy-dispersive X-ray spectroscopy, was used to characterize phytoliths in Miscanthus sinensis, its dry extracts, and in the cyclone ash produced by the semi-industrial (400 kW) burning of this energy crop. The results show that the phytoliths are made of opal, SiO2 center dot n(H2O). X-ray powder diffraction data document that the SiO2-rich (31.7 wt%) cyclone ash consists of nearly 83 wt% amorphous material, which reflects the abundance of phytoliths in the studied materials. The cyclone ash also contains high amounts of some heavy metals, which suggests that Miscanthus sinensis is suitable for bioremediation of contaminated soils. |
Deroche, Irena; Daou, Jean T; Picard, Cyril; Coasne, Benoit Reminiscent capillarity in subnanopores Article de journal Nature Communications, 10 , p. 4642, 2019. @article{Deroche2019, title = {Reminiscent capillarity in subnanopores}, author = { Irena Deroche and T. Jean Daou and Cyril Picard and Benoit Coasne}, doi = {10.1038/s41467-019-12418-9}, year = {2019}, date = {2019-10-01}, journal = {Nature Communications}, volume = {10}, pages = {4642}, abstract = {Fluids in large and small pores display different behaviors with a crossover described through the concept of critical capillarity. Here we report experimental and simulation data for various siliceous zeolites and adsorbates that show unexpected reminiscent capillarity for such nanoporous materials. For pore sizes D exceeding the fluid molecule size, the filling pressures p are found to follow a generic behavior k(B)T In p similar to gamma/rho D where gamma and rho are the fluid surface tension and density. This result is rationalized by showing that the filling chemical potential for such ultra-small pores is the sum of an adsorption energy and a capillary energy that remains meaningful even for severe confinements. A phenomenological model, based on Derjaguin's formalism to bridge macroscopic and molecular theories for condensation in porous materials, is developed to account for the behavior of fluids confined down to the molecular scale from simple parameters.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Fluids in large and small pores display different behaviors with a crossover described through the concept of critical capillarity. Here we report experimental and simulation data for various siliceous zeolites and adsorbates that show unexpected reminiscent capillarity for such nanoporous materials. For pore sizes D exceeding the fluid molecule size, the filling pressures p are found to follow a generic behavior k(B)T In p similar to gamma/rho D where gamma and rho are the fluid surface tension and density. This result is rationalized by showing that the filling chemical potential for such ultra-small pores is the sum of an adsorption energy and a capillary energy that remains meaningful even for severe confinements. A phenomenological model, based on Derjaguin's formalism to bridge macroscopic and molecular theories for condensation in porous materials, is developed to account for the behavior of fluids confined down to the molecular scale from simple parameters. |
Dietlin, Celine; Trinh, Thanh Tam; Schweizer, Stephane; Graff, Bernadette; Morlet-Savary, Fabrice; Noirot, Pierre-Antoine; Lalevee, Jacques Rational Design of Acyldiphenylphosphine Oxides as Photoinitiators of Radical Polymerization Article de journal Macromolecules, 52 (20), p. 7886–7893, 2019. @article{Dietlin2019, title = {Rational Design of Acyldiphenylphosphine Oxides as 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 = {10.1021/acs.macromol.9b01724}, year = {2019}, date = {2019-10-01}, journal = {Macromolecules}, volume = {52}, number = {20}, pages = {7886--7893}, abstract = {Some efficient acylphosphine oxides have been used for many years as photoinitiators of radical polymerization. As very few new acylphosphine oxide compounds have been proposed these past years for the radical polymerization of methacrylates, the aim of this work is to use molecular modeling to select potentially reactive compounds before their synthesis to see whether acyldiphenylphosphine oxide (ADPO) molecules can compete or even work better than commercial and well-established acylphosphine oxides. Two of the common acylphosphine oxides, TPO-L and BAPO, used in industrial applications will be taken as references in this work, while new ADPO will be evaluated in photopolymerization reaction initiated upon LED at 395 nm. In fact, the photopolymerization industrial technology is evolving from the use of an energy-consuming Hg lamp toward the use of safer LEDs working typically in the 385-405 nm range. At least two of the compounds are competing or working better than the well-established systems in a reference benchmarked acrylic resin, evidencing the importance of molecular modeling for the design of new photoinitiators before their synthesis.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Some efficient acylphosphine oxides have been used for many years as photoinitiators of radical polymerization. As very few new acylphosphine oxide compounds have been proposed these past years for the radical polymerization of methacrylates, the aim of this work is to use molecular modeling to select potentially reactive compounds before their synthesis to see whether acyldiphenylphosphine oxide (ADPO) molecules can compete or even work better than commercial and well-established acylphosphine oxides. Two of the common acylphosphine oxides, TPO-L and BAPO, used in industrial applications will be taken as references in this work, while new ADPO will be evaluated in photopolymerization reaction initiated upon LED at 395 nm. In fact, the photopolymerization industrial technology is evolving from the use of an energy-consuming Hg lamp toward the use of safer LEDs working typically in the 385-405 nm range. At least two of the compounds are competing or working better than the well-established systems in a reference benchmarked acrylic resin, evidencing the importance of molecular modeling for the design of new photoinitiators before their synthesis. |
Arfi, Rim Ben; Karoui, Sarra; Mougin, Karine; Ghorbal, Achraf Cetyltrimethylammonium bromide-treated Phragmites australis powder as novel polymeric adsorbent for hazardous Eriochrome Black T removal from aqueous solutions Article de journal Polymer Bulletin, 76 (10), p. 5077–5102, 2019. @article{BenArfi2019, title = {Cetyltrimethylammonium bromide-treated Phragmites australis powder as novel polymeric adsorbent for hazardous Eriochrome Black T removal from aqueous solutions}, author = { Rim Ben Arfi and Sarra Karoui and Karine Mougin and Achraf Ghorbal}, doi = {10.1007/s00289-018-2648-8}, year = {2019}, date = {2019-10-01}, journal = {Polymer Bulletin}, volume = {76}, number = {10}, pages = {5077--5102}, abstract = {The potential of cetyltrimethylammonium bromide-treated Phragmites australis powder (CTAB-PA) as a novel polymeric sorbent for Eriochrome Black T (EBT) removal was studied. CTAB impregnation process increased adsorption sites availability that led to a better interaction of EBT dye and CTAB-PA. CTAB impregnation process increased the PA monolayer adsorption capacity from 57.14 to 89.93 mg g(-1). Adsorption data were modeled using chemical reaction-based kinetic models (pseudo-first-order, pseudo-second-order, and Elovich models) and diffusion-based kinetic models (Weber-Morris and Boyd models). EBT sorption kinetics could be described by the pseudo-second-order model having film diffusion as the main rate-limiting step. Adsorption data for both adsorbents were fitted to Langmuir, Freundlich, Temkin, and Dubinin-Radushkevich models, and best fitting was obtained with Langmuir model. Thermodynamic functions indicated that EBT adsorption onto PA and CTAB-PA was an exothermic and physical process. CTAB-PA burning behavior showed that this novel adsorbent can be considered as flame-retarding material. Adsorption-desorption experiments revealed that CTAB-PA could be reused up to five cycles with recovery percentage values maintained higher than 71%. CTAB-PA, a low-cost, durable, flame-retarding, and reusable material, was found to be an attractive candidate for EBT removal from water.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The potential of cetyltrimethylammonium bromide-treated Phragmites australis powder (CTAB-PA) as a novel polymeric sorbent for Eriochrome Black T (EBT) removal was studied. CTAB impregnation process increased adsorption sites availability that led to a better interaction of EBT dye and CTAB-PA. CTAB impregnation process increased the PA monolayer adsorption capacity from 57.14 to 89.93 mg g(-1). Adsorption data were modeled using chemical reaction-based kinetic models (pseudo-first-order, pseudo-second-order, and Elovich models) and diffusion-based kinetic models (Weber-Morris and Boyd models). EBT sorption kinetics could be described by the pseudo-second-order model having film diffusion as the main rate-limiting step. Adsorption data for both adsorbents were fitted to Langmuir, Freundlich, Temkin, and Dubinin-Radushkevich models, and best fitting was obtained with Langmuir model. Thermodynamic functions indicated that EBT adsorption onto PA and CTAB-PA was an exothermic and physical process. CTAB-PA burning behavior showed that this novel adsorbent can be considered as flame-retarding material. Adsorption-desorption experiments revealed that CTAB-PA could be reused up to five cycles with recovery percentage values maintained higher than 71%. CTAB-PA, a low-cost, durable, flame-retarding, and reusable material, was found to be an attractive candidate for EBT removal from water. |
Eren, Tugce Nur; Lalevee, Jacques; Avci, Duygu Bisphosphonic Acid-Functionalized Water-Soluble Photoinitiators Article de journal Macromolecular Chemistry and Physics, 220 (19), p. 1900268, 2019. @article{Eren2019a, title = {Bisphosphonic Acid-Functionalized Water-Soluble Photoinitiators}, author = { Tugce Nur Eren and Jacques Lalevee and Duygu Avci}, doi = {10.1002/macp.201900268}, year = {2019}, date = {2019-10-01}, journal = {Macromolecular Chemistry and Physics}, volume = {220}, number = {19}, pages = {1900268}, abstract = {The first bisphosphonic acid-functionalized benzophenone (BP) and thioxanthone (TX) photoinitiators (PIs), BPBP and TXBP, are synthesized as a new class of water-soluble PIs for free radical polymerization. BPBP shows excellent solubility (28 g L-1) in water at ambient temperature, compared to TXBP (0.05 g L-1) and also the commercial PI Irgacure 2959 (5 g L-1). BPBP and TXBP show UV-vis absorption at approximate to 260 (epsilon = 12912) and 405 (epsilon = 3314) nm in water. Photopolymerization results demonstrate that they can successfully initiate the photopolymerization of poly(ethylene glycol) diacrylate (M-n = 250 D) in the presence of bis-(4-tert-butylphenyl)-iodonium hexafluorophosphate (Iod). The photochemical mechanisms are investigated by electron-spin resonance-spin trapping, fluorescence, and steady-state photolysis techniques.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The first bisphosphonic acid-functionalized benzophenone (BP) and thioxanthone (TX) photoinitiators (PIs), BPBP and TXBP, are synthesized as a new class of water-soluble PIs for free radical polymerization. BPBP shows excellent solubility (28 g L-1) in water at ambient temperature, compared to TXBP (0.05 g L-1) and also the commercial PI Irgacure 2959 (5 g L-1). BPBP and TXBP show UV-vis absorption at approximate to 260 (epsilon = 12912) and 405 (epsilon = 3314) nm in water. Photopolymerization results demonstrate that they can successfully initiate the photopolymerization of poly(ethylene glycol) diacrylate (M-n = 250 D) in the presence of bis-(4-tert-butylphenyl)-iodonium hexafluorophosphate (Iod). The photochemical mechanisms are investigated by electron-spin resonance-spin trapping, fluorescence, and steady-state photolysis techniques. |
Gerard, Violaine; Ay, Emel; Graff, Bernadette; Morlet-Savary, Fabrice; Galopin, Christophe; Mutilangi, William; Lalevee, Jacques Ascorbic Acid Derivatives as Potential Substitutes for Ascorbic Acid To Reduce Color Degradation of Drinks Containing Ascorbic Acid and Anthocyanins from Natural Extracts. Article de journal Journal of agricultural and food chemistry, 67 (43), p. 12061–12071, 2019. @article{Gerard2019a, title = {Ascorbic Acid Derivatives as Potential Substitutes for Ascorbic Acid To Reduce Color Degradation of Drinks Containing Ascorbic Acid and Anthocyanins from Natural Extracts.}, author = { Violaine Gerard and Emel Ay and Bernadette Graff and Fabrice Morlet-Savary and Christophe Galopin and William Mutilangi and Jacques Lalevee}, doi = {10.1021/acs.jafc.9b05049}, year = {2019}, date = {2019-10-01}, journal = {Journal of agricultural and food chemistry}, volume = {67}, number = {43}, pages = {12061--12071}, abstract = {Ascorbic acid is widely used in the food industry as a source of vitamin C or as antioxidant. However, it degrades quickly in beverages at acidic pH and can accelerate the degradation of anthocyanins, natural dyes used in beverages, leading to a loss of color. In this work, we investigated the possibility to replace ascorbic acid by ascorbic acid derivatives to prevent its degradation effect on anthocyanins from natural extracts (black carrot, grape juice, and purple sweet potato). For this, the thermal and photolytic stabilities under air and under N2 of ascorbic acid (as reference) and of some ascorbic acid derivatives (3-O-ethyl-l-ascorbic acid, 2-O-alpha-d-glucopyranosyl-l-ascorbic acid, l-ascorbic acid 2-phosphate sesquimagnesium salt hydrate, l-ascorbyl 2,6-dibutyrate, glyceryl ascorbate, (+)-5,6-O-isopropylidene-l-ascorbic acid), soluble in aqueous model beverages, were studied alone and in the presence of anthocyanins from the natural extracts in citrate buffer at pH 3. The stability was followed by UV-visible spectrometry. To extend the investigation, some properties of the ascorbic acid derivatives (pKa, oxidation potential, bond dissociation energy, ionization potential) were also determined. Moreover, the addition of chlorogenic acid was examined to further stabilize the mixture of anthocyanins with 2-O-alpha-d-glucopyranosyl-l-ascorbic acid, a promising ascorbic acid derivative.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Ascorbic acid is widely used in the food industry as a source of vitamin C or as antioxidant. However, it degrades quickly in beverages at acidic pH and can accelerate the degradation of anthocyanins, natural dyes used in beverages, leading to a loss of color. In this work, we investigated the possibility to replace ascorbic acid by ascorbic acid derivatives to prevent its degradation effect on anthocyanins from natural extracts (black carrot, grape juice, and purple sweet potato). For this, the thermal and photolytic stabilities under air and under N2 of ascorbic acid (as reference) and of some ascorbic acid derivatives (3-O-ethyl-l-ascorbic acid, 2-O-alpha-d-glucopyranosyl-l-ascorbic acid, l-ascorbic acid 2-phosphate sesquimagnesium salt hydrate, l-ascorbyl 2,6-dibutyrate, glyceryl ascorbate, (+)-5,6-O-isopropylidene-l-ascorbic acid), soluble in aqueous model beverages, were studied alone and in the presence of anthocyanins from the natural extracts in citrate buffer at pH 3. The stability was followed by UV-visible spectrometry. To extend the investigation, some properties of the ascorbic acid derivatives (pKa, oxidation potential, bond dissociation energy, ionization potential) were also determined. Moreover, the addition of chlorogenic acid was examined to further stabilize the mixture of anthocyanins with 2-O-alpha-d-glucopyranosyl-l-ascorbic acid, a promising ascorbic acid derivative. |
Thiebault, Thomas; Brendle, Jocelyne; Auge, Gregoire; Limousy, Lionel Green Chemistry, 21 (18), p. 5118–5127, 2019. @article{Thiebault2019, title = {Zwitterionic-surfactant modified LAPONITE (R) s for removal of ions (Cs+, Sr2+ and Co2+) from aqueous solutions as a sustainable recovery method for radionuclides from aqueous wastes}, author = { Thomas Thiebault and Jocelyne Brendle and Gregoire Auge and Lionel Limousy}, doi = {10.1039/c9gc02243k}, year = {2019}, date = {2019-09-01}, journal = {Green Chemistry}, volume = {21}, number = {18}, pages = {5118--5127}, abstract = {The synthesis of zwitterionic-surfactant modified LAPONITE (R) s (LAP-CBs) was investigated as a function of the surfactant loading in order to obtain a suitable adsorbent for the removal of Co2+, Sr2+ and Cs+ ions from aqueous solutions. The proper adsorption of surfactant was characterized by several techniques that emphasized the modification of the surfactant distribution between the interlayer space and the surface of LAPONITE (R) (LAP), with increasing loading of surfactant. The organophilic character of the obtained LAP-CBs strongly affected their affinity for the targeted contaminants. The adsorption of Sr2+ was lower on LAP-CBs in comparison to that on LAP, while the adsorption of Co2+ and Cs+ was strongly improved. The competition between Sr2+ and Cs+ was important for LAP-CBs adsorption, whereas no competition was found when using LAP, indicating that the adsorption mechanism differed depending on the adsorbent. The desorption of contaminants was performed in various solutions and confirmed these mechanisms. Whereas Cs+ and Sr2+ were adsorbed through cation exchange onto LAP-CBs, as highlighted by a significant desorption in saline solution, the desorption of Co2+ from LAP-CBs was very poor whatever the composition of the release solution, indicating adsorption by complexation. Finally, increasing the load of surfactant decreased the adsorption capacity of the adsorbent for all of the investigated contaminants. The arrangement of the surfactant, within the interlayer space or on the surface of LAP, was therefore a critical factor when considering the potential of this material to durably remove radionuclides from low-level radioactive wastewaters.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The synthesis of zwitterionic-surfactant modified LAPONITE (R) s (LAP-CBs) was investigated as a function of the surfactant loading in order to obtain a suitable adsorbent for the removal of Co2+, Sr2+ and Cs+ ions from aqueous solutions. The proper adsorption of surfactant was characterized by several techniques that emphasized the modification of the surfactant distribution between the interlayer space and the surface of LAPONITE (R) (LAP), with increasing loading of surfactant. The organophilic character of the obtained LAP-CBs strongly affected their affinity for the targeted contaminants. The adsorption of Sr2+ was lower on LAP-CBs in comparison to that on LAP, while the adsorption of Co2+ and Cs+ was strongly improved. The competition between Sr2+ and Cs+ was important for LAP-CBs adsorption, whereas no competition was found when using LAP, indicating that the adsorption mechanism differed depending on the adsorbent. The desorption of contaminants was performed in various solutions and confirmed these mechanisms. Whereas Cs+ and Sr2+ were adsorbed through cation exchange onto LAP-CBs, as highlighted by a significant desorption in saline solution, the desorption of Co2+ from LAP-CBs was very poor whatever the composition of the release solution, indicating adsorption by complexation. Finally, increasing the load of surfactant decreased the adsorption capacity of the adsorbent for all of the investigated contaminants. The arrangement of the surfactant, within the interlayer space or on the surface of LAP, was therefore a critical factor when considering the potential of this material to durably remove radionuclides from low-level radioactive wastewaters. |
Liu, Yinghui; Rety, Benedicte; Ghimbeu, Camelia Matei; Soucaze-Guillous, Benoit; Taberna, Pierre-Louis; Simon, Patrice Understanding ageing mechanisms of porous carbons in non-aqueous electrolytes for supercapacitors applications Article de journal Journal of Power Sources, 434 , p. 226734, 2019. @article{Liu2019, title = {Understanding ageing mechanisms of porous carbons in non-aqueous electrolytes for supercapacitors applications}, author = { Yinghui Liu and Benedicte Rety and Camelia Matei Ghimbeu and Benoit Soucaze-Guillous and Pierre-Louis Taberna and Patrice Simon}, doi = {10.1016/j.jpowsour.2019.226734}, year = {2019}, date = {2019-09-01}, journal = {Journal of Power Sources}, volume = {434}, pages = {226734}, abstract = {Two activated porous carbon powders with different surface functional groups content have been electrochemically polarized in tetraethylammonium tetrafluoborate (Et4NBF4) in acetonitrile electrolyte to study their ageing mechanism as supercapacitor electrodes. Temperature-programmed desorption coupled with mass spectrometry technique (TPD-MS) is used to track the change of carbon surface chemistry - surface functional groups and/or adsorption of degradation products occurring upon polarizations. A potentiostatic study of the carbons in a two-compartment cell unveil the catalytic role of water in the ageing mechanism. Combining these results with our previous work, we propose different scenarios to depict the ageing mechanisms of the two carbons. For carbon A, hydrolysis of BF4- at the positive electrode leads to carbon oxidation together with soluble poly-acetonitrile oligomer occurred from reaction between B-4(center dot) radicals and acetonitrile. Ageing mechanism is also assumed to set off with the hydrolysis of BF4- for carbon B; but, in here the formed oligomers react with acid functional groups present at the carbon surface to form a protective, passive-like layer at both positive and negative electrodes which hampers a further electrode ageing.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Two activated porous carbon powders with different surface functional groups content have been electrochemically polarized in tetraethylammonium tetrafluoborate (Et4NBF4) in acetonitrile electrolyte to study their ageing mechanism as supercapacitor electrodes. Temperature-programmed desorption coupled with mass spectrometry technique (TPD-MS) is used to track the change of carbon surface chemistry - surface functional groups and/or adsorption of degradation products occurring upon polarizations. A potentiostatic study of the carbons in a two-compartment cell unveil the catalytic role of water in the ageing mechanism. Combining these results with our previous work, we propose different scenarios to depict the ageing mechanisms of the two carbons. For carbon A, hydrolysis of BF4- at the positive electrode leads to carbon oxidation together with soluble poly-acetonitrile oligomer occurred from reaction between B-4(center dot) radicals and acetonitrile. Ageing mechanism is also assumed to set off with the hydrolysis of BF4- for carbon B; but, in here the formed oligomers react with acid functional groups present at the carbon surface to form a protective, passive-like layer at both positive and negative electrodes which hampers a further electrode ageing. |
2020 |
Amirou, Siham; Pizzi, Antonio; Delmotte, Luc Investigations of mechanical properties and chemical changes occurring during welding of thermally modified ash wood (Article de journal) Journal of Adhesion Science and Technology, 34 (1), p. 13–24, 2020. @article{Amirou2020, title = {Investigations of mechanical properties and chemical changes occurring during welding of thermally modified ash wood}, author = { Siham Amirou and Antonio Pizzi and Luc Delmotte}, doi = {10.1080/01694243.2019.1659569}, year = {2020}, date = {2020-01-01}, journal = {Journal of Adhesion Science and Technology}, volume = {34}, number = {1}, pages = {13--24}, abstract = {Heat treatment of wood appears as an ecological and environmentally friendly alternative in the field of wood treatment. Generally, thermal modification increase dimensional stability by reduces of hygroscopicity and water absorption but it makes it difficult to bonding in some application. During welding, changes in the morphological, chemical, and physical properties of the wood cell wall are observed due to the compression and high temperatures produced by welding. Also, the degradation of cell wall in the wood causes some mechanical properties are reduced. This modification appears without any effect on the linear welding of thermal-ash wood. Scanning electron microscopy (SEM) and nuclear magnetic resonance (NMR) were used for evaluation of properties of wood-welding systems and their interactions. The mass spectrometry (MS) analysis was used to identifying the organic degradation products emitted during welding of thermo-ash. The results of experiments show that the use of friction welding for the bonding of thermal ash wood in dry conditions was possible, and we had good results. The best combination was with a welding time of 3.5 s devised to 0.5 s and 3 s and welding pressure 2.5 and 4 MPa, respectively. The result obtained is comparable to the result obtained with EPI adhesives. Welding time greater than 3.5 MPa negatively affects the welding quality and gives low the mechanical strength.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Heat treatment of wood appears as an ecological and environmentally friendly alternative in the field of wood treatment. Generally, thermal modification increase dimensional stability by reduces of hygroscopicity and water absorption but it makes it difficult to bonding in some application. During welding, changes in the morphological, chemical, and physical properties of the wood cell wall are observed due to the compression and high temperatures produced by welding. Also, the degradation of cell wall in the wood causes some mechanical properties are reduced. This modification appears without any effect on the linear welding of thermal-ash wood. Scanning electron microscopy (SEM) and nuclear magnetic resonance (NMR) were used for evaluation of properties of wood-welding systems and their interactions. The mass spectrometry (MS) analysis was used to identifying the organic degradation products emitted during welding of thermo-ash. The results of experiments show that the use of friction welding for the bonding of thermal ash wood in dry conditions was possible, and we had good results. The best combination was with a welding time of 3.5 s devised to 0.5 s and 3 s and welding pressure 2.5 and 4 MPa, respectively. The result obtained is comparable to the result obtained with EPI adhesives. Welding time greater than 3.5 MPa negatively affects the welding quality and gives low the mechanical strength. |
Khiari, Besma; Ghouma, Imen; Ferjani, Amel Ibn; Azzaz, Ahmed Amine; Jellali, Salah; Limousy, Lionel; Jeguirim, Mejdi Kenaf stems: Thermal characterization and conversion for biofuel and biochar production (Article de journal) Fuel, 262 , p. UNSP 116654, 2020. @article{Khiari2020, title = {Kenaf stems: Thermal characterization and conversion for biofuel and biochar production}, author = { Besma Khiari and Imen Ghouma and Amel Ibn Ferjani and Ahmed Amine Azzaz and Salah Jellali and Lionel Limousy and Mejdi Jeguirim}, doi = {10.1016/j.fuel.2019.116654}, year = {2020}, date = {2020-01-01}, journal = {Fuel}, volume = {262}, pages = {UNSP 116654}, abstract = {Kenaf stems are characterized in this present investigation in order to assess their suitability in energy recovery through a pyrolysis process and to identify sustainable applications of the generated biochar. In particular, the raw biomass properties are analyzed using numerous analytical techniques such as thermogravimetric analyses (TGA/DTG), X-Ray Fluorescence (XRF) and Scanning Electronic Microscopy (SEM). First, the thermogravimetric analyses monitor the pyrolysis parameters, control the proportion of its outputs and allow to extract the kinetic parameters. The latter is determined using Friedman, Flynn-Wall-Ozawa (FWO) and Kissinger-Akahira-Sunose (KAS) models. In a second step, Kenaf derived chars are produced at different pyrolysis temperatures and their physicochemical, morphological, textural and structural properties are determined using different techniques such as CO2 adsorption, Raman Spectroscopy, and DRIFT Spectroscopy. The main results confirm the Kenaf potential for energy applications as its thermal properties are more interesting compared to other usual crops. The Kenaf stem derived char is also very promising for pollutants removal or gas storage as its surface area as well as its microporous structure are interestingly developed when increasing the pyrolysis temperature. Kenaf char could be also chemically or physically activated in order to be used for pollutants removal from gaseous and aqueous effluents. Finally, the XRF analysis indicated that contents in K and P elements are high. Ca and Mg are also major mineral species in the char. These contents indicate that Kenaf derived char could be also suitable for agricultural soil amendments.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Kenaf stems are characterized in this present investigation in order to assess their suitability in energy recovery through a pyrolysis process and to identify sustainable applications of the generated biochar. In particular, the raw biomass properties are analyzed using numerous analytical techniques such as thermogravimetric analyses (TGA/DTG), X-Ray Fluorescence (XRF) and Scanning Electronic Microscopy (SEM). First, the thermogravimetric analyses monitor the pyrolysis parameters, control the proportion of its outputs and allow to extract the kinetic parameters. The latter is determined using Friedman, Flynn-Wall-Ozawa (FWO) and Kissinger-Akahira-Sunose (KAS) models. In a second step, Kenaf derived chars are produced at different pyrolysis temperatures and their physicochemical, morphological, textural and structural properties are determined using different techniques such as CO2 adsorption, Raman Spectroscopy, and DRIFT Spectroscopy. The main results confirm the Kenaf potential for energy applications as its thermal properties are more interesting compared to other usual crops. The Kenaf stem derived char is also very promising for pollutants removal or gas storage as its surface area as well as its microporous structure are interestingly developed when increasing the pyrolysis temperature. Kenaf char could be also chemically or physically activated in order to be used for pollutants removal from gaseous and aqueous effluents. Finally, the XRF analysis indicated that contents in K and P elements are high. Ca and Mg are also major mineral species in the char. These contents indicate that Kenaf derived char could be also suitable for agricultural soil amendments. |
Bennici, Simona; Polimann, Teo; Ondarts, Michel; Gonze, Evelyne; Vaulot, Cyril; Pierres, Nolwenn Le Long-term impact of air pollutants on thermochemical heat storage materials (Article de journal) Renewable & Sustainable Energy Reviews, 117 , p. 109473, 2020. @article{Bennici2020, title = {Long-term impact of air pollutants on thermochemical heat storage materials}, author = { Simona Bennici and Teo Polimann and Michel Ondarts and Evelyne Gonze and Cyril Vaulot and Nolwenn Le Pierres}, doi = {10.1016/j.rser.2019.109473}, year = {2020}, date = {2020-01-01}, journal = {Renewable & Sustainable Energy Reviews}, volume = {117}, pages = {109473}, abstract = {Heating of buildings is a highly energy-demanding task. Therefore, improving energy management is crucial for more environmentally friendly development of future constructions, and the use of thermochemical heat storage technologies in solid materials is one of the most promising solutions. Nevertheless, certain drawbacks such as the impact of air pollutants on the long term durability of thermochemical heat storage materials (ageing up to 30 years) need to be studied to implement installations. In certain thermochemical heat storage systems, air passes through porous materials to carry water and heat, and the air's pollutants can interact with the solid material, thus decreasing its storage capacity. In the present work, adsorption tests were performed (under dynamic conditions) on zeolite-base materials, using different model molecules (i.e. toluene, styrene and hexaldehyde) representative of air pollutants. Strong competition between the adsorption of pollutants and water on the storage material was demonstrated. Water molecules were able to displace the molecules of pollutants, previously adsorbed on the material surface, thus delaying the saturation of the material and extending its life. Nevertheless, a lowering of the water adsorption and heat storage capacity was measured for a high number of cycles. The cycled materials have been thoroughly characterised in their physicochemical properties to identify the modifications of the materials (i.e., dealumination) and correlate them with the heat storage capacity. The impact of pollutants was demonstrated to be stronger on the pure zeolite, while the salt present on the MgSO4/13x composite seems to protect the material surface from the pollutant effect.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Heating of buildings is a highly energy-demanding task. Therefore, improving energy management is crucial for more environmentally friendly development of future constructions, and the use of thermochemical heat storage technologies in solid materials is one of the most promising solutions. Nevertheless, certain drawbacks such as the impact of air pollutants on the long term durability of thermochemical heat storage materials (ageing up to 30 years) need to be studied to implement installations. In certain thermochemical heat storage systems, air passes through porous materials to carry water and heat, and the air's pollutants can interact with the solid material, thus decreasing its storage capacity. In the present work, adsorption tests were performed (under dynamic conditions) on zeolite-base materials, using different model molecules (i.e. toluene, styrene and hexaldehyde) representative of air pollutants. Strong competition between the adsorption of pollutants and water on the storage material was demonstrated. Water molecules were able to displace the molecules of pollutants, previously adsorbed on the material surface, thus delaying the saturation of the material and extending its life. Nevertheless, a lowering of the water adsorption and heat storage capacity was measured for a high number of cycles. The cycled materials have been thoroughly characterised in their physicochemical properties to identify the modifications of the materials (i.e., dealumination) and correlate them with the heat storage capacity. The impact of pollutants was demonstrated to be stronger on the pure zeolite, while the salt present on the MgSO4/13x composite seems to protect the material surface from the pollutant effect. |
Huve, Joffrey; Daou, Jean T; Nouali, Habiba; Patarin, Joel; Ryzhikov, Andrey The effect of nanostructures on high pressure intrusion-extrusion of water and electrolyte solutions in hierarchical nanoboxes of silicalite-1 (Article de journal) New Journal of Chemistry, 44 (1), p. 273–281, 2020. @article{Huve2020, title = {The effect of nanostructures on high pressure intrusion-extrusion of water and electrolyte solutions in hierarchical nanoboxes of silicalite-1}, author = { Joffrey Huve and T. Jean Daou and Habiba Nouali and Joel Patarin and Andrey Ryzhikov}, doi = {10.1039/c9nj01891c}, year = {2020}, date = {2020-01-01}, journal = {New Journal of Chemistry}, volume = {44}, number = {1}, pages = {273--281}, abstract = {This study of high pressure intrusion-extrusion of water and 20 M LiCl solution in silicalite-1 nanoboxes demonstrates how nanostructures can determine the properties of materials. The drastic effect of the presence of cavities on the intrusion-extrusion behavior and characteristics has been observed, particularly, in the case of LiCl aqueous solution. The nanoboxes demonstrate a combination of bumper and spring behavior in the first intrusion-extrusion cycle. The intrusion of 20 M LiCl solution is only partially reversible and takes place in two clearly marked steps, whereas only one intrusion step with a fully reversible spring behavior is observed for the micro- and nanocrystals. The first step, with an intruded volume of 0.07 mL g(-1) and an intruded pressure of 98 MPa, is irreversible and corresponds probably to the filling of mesoporous cavities, and the second one, with an intruded volume of 0.08 mL g(-1) and an intrusion pressure of 273 MPa, is fully reversible and related to the filling of the micropores of silicalite-1 walls. The filling of the nanocavities occurs probably through small mesoporous cracks in the nanobox walls. The characterization by structural and physicochemical methods shows that the dissolution-recrystallization process leads to the formation of a MFI structure with lower content of silanol defects in comparison with initial nanocrystals explaining the steeper slope of the intrusion step and the higher intrusion pressure observed for the "nanobox-H2O" and "nanobox-20 M LiCl" systems.}, keywords = {}, pubstate = {published}, tppubtype = {article} } This study of high pressure intrusion-extrusion of water and 20 M LiCl solution in silicalite-1 nanoboxes demonstrates how nanostructures can determine the properties of materials. The drastic effect of the presence of cavities on the intrusion-extrusion behavior and characteristics has been observed, particularly, in the case of LiCl aqueous solution. The nanoboxes demonstrate a combination of bumper and spring behavior in the first intrusion-extrusion cycle. The intrusion of 20 M LiCl solution is only partially reversible and takes place in two clearly marked steps, whereas only one intrusion step with a fully reversible spring behavior is observed for the micro- and nanocrystals. The first step, with an intruded volume of 0.07 mL g(-1) and an intruded pressure of 98 MPa, is irreversible and corresponds probably to the filling of mesoporous cavities, and the second one, with an intruded volume of 0.08 mL g(-1) and an intrusion pressure of 273 MPa, is fully reversible and related to the filling of the micropores of silicalite-1 walls. The filling of the nanocavities occurs probably through small mesoporous cracks in the nanobox walls. The characterization by structural and physicochemical methods shows that the dissolution-recrystallization process leads to the formation of a MFI structure with lower content of silanol defects in comparison with initial nanocrystals explaining the steeper slope of the intrusion step and the higher intrusion pressure observed for the "nanobox-H2O" and "nanobox-20 M LiCl" systems. |
Sciacca, Davide; Peric, Nemanja; Berthe, Maxime; Biadala, Louis; Pirri, Carmelo; Derivaz, Mickael; Massara, Natalia; Diener, Pascale; Grandidier, Bruno Account of the diversity of tunneling spectra at the germanene/Al(111) interface (Article de journal) Journal of Physics-condensed Matter, 32 (5), p. 055002, 2020. @article{Sciacca2020, title = {Account of the diversity of tunneling spectra at the germanene/Al(111) interface}, author = { Davide Sciacca and Nemanja Peric and Maxime Berthe and Louis Biadala and Carmelo Pirri and Mickael Derivaz and Natalia Massara and Pascale Diener and Bruno Grandidier}, doi = {10.1088/1361-648X/ab4d15}, year = {2020}, date = {2020-01-01}, journal = {Journal of Physics-condensed Matter}, volume = {32}, number = {5}, pages = {055002}, abstract = {Despite the wealth of tunneling spectroscopic studies performed on silicene and germanene, the observation of a well-defined Dirac cone in these materials remains elusive. Here, we study germanene grown on Al(1 1 1) at submonolayer coverages with low temperature scanning tunneling spectroscopy. We show that the tunnelling spectra of the Al(1 1 1) surface and the germanene nanosheets are identical. They exhibit a clear metallic behaviour at the beginning of the experiments, that highlights the strong electronic coupling between the adlayer and the substrate. Over the course of the experiments, the spectra deviate from this initial behaviour, although consecutive spectra measured on the Al(1 1 1) surface and germanene nanosheets are still similar. This spectral diversity is explained by modifications of the tip apex, that arise from the erratic manipulation of the germanium adlayer. The origin of the characteristic features such as a wide band gap, coherence-like peaks or zero-bias anomalies are tentatively discussed in light of the physical properties of Ge and AlGe alloy clusters, that are likely to adsorb at the tip apex.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Despite the wealth of tunneling spectroscopic studies performed on silicene and germanene, the observation of a well-defined Dirac cone in these materials remains elusive. Here, we study germanene grown on Al(1 1 1) at submonolayer coverages with low temperature scanning tunneling spectroscopy. We show that the tunnelling spectra of the Al(1 1 1) surface and the germanene nanosheets are identical. They exhibit a clear metallic behaviour at the beginning of the experiments, that highlights the strong electronic coupling between the adlayer and the substrate. Over the course of the experiments, the spectra deviate from this initial behaviour, although consecutive spectra measured on the Al(1 1 1) surface and germanene nanosheets are still similar. This spectral diversity is explained by modifications of the tip apex, that arise from the erratic manipulation of the germanium adlayer. The origin of the characteristic features such as a wide band gap, coherence-like peaks or zero-bias anomalies are tentatively discussed in light of the physical properties of Ge and AlGe alloy clusters, that are likely to adsorb at the tip apex. |
Oliveira, Larissa V F; Bennici, Simona; Josien, Ludovic; Limousy, Lionel; Bizeto, Marcos A; Camilo, Fernanda F Free-standing cellulose film containing manganese dioxide nanoparticles and its use in discoloration of indigo carmine dye (Article de journal) Carbohydrate Polymers, 230 , p. 115621, 2020. @article{Oliveira2020, title = {Free-standing cellulose film containing manganese dioxide nanoparticles and its use in discoloration of indigo carmine dye}, author = { Larissa V. F. Oliveira and Simona Bennici and Ludovic Josien and Lionel Limousy and Marcos A. Bizeto and Fernanda F. Camilo}, doi = {10.1016/j.carbpol.2019.115621}, year = {2020}, date = {2020-01-01}, journal = {Carbohydrate Polymers}, volume = {230}, pages = {115621}, abstract = {In this study, we report the production of a free-standing film of non-modified cellulose impregnated with 12 wt % of MnO2 nanoparticles with less than 100 nm in size. The method here described can be applied to the immobilization of different types of nanoparticles. The film was prepared by dissolving microcrystalline cellulose in an ionic liquid followed by its regeneration by adding water to the former solution. Then, the wet film was impregnated with the nanoparticles by dipping it in a MnO2 dispersion. Electron microscopy images revealed manganese dioxide nanoparticles distributed not only at the film surface but also in its interior. The cellulose film impregnated with MnO2 nanoparticles was capable of efficiently discolouring an Indigo Carmine dye solution in 25 min upon ambient light. The film was easily removed from the dye solution and repeatedly reused for at least 10 times without losing its discolouring efficiency.}, keywords = {}, pubstate = {published}, tppubtype = {article} } In this study, we report the production of a free-standing film of non-modified cellulose impregnated with 12 wt % of MnO2 nanoparticles with less than 100 nm in size. The method here described can be applied to the immobilization of different types of nanoparticles. The film was prepared by dissolving microcrystalline cellulose in an ionic liquid followed by its regeneration by adding water to the former solution. Then, the wet film was impregnated with the nanoparticles by dipping it in a MnO2 dispersion. Electron microscopy images revealed manganese dioxide nanoparticles distributed not only at the film surface but also in its interior. The cellulose film impregnated with MnO2 nanoparticles was capable of efficiently discolouring an Indigo Carmine dye solution in 25 min upon ambient light. The film was easily removed from the dye solution and repeatedly reused for at least 10 times without losing its discolouring efficiency. |
Berger, M; Dorge, S; Nouali, H; Habermacher, D; Fiani, E; Vierling, M; Moliere, M; Brilhac, J F; Patarin, J Desulfurization process: understanding of the behaviour of the CuO/SBA-15 type SOx adsorbent in the presence of NO/NO2 and CO/CO2 flue gas environmental pollutants (Article de journal) Chemical Engineering Journal, 384 , p. 123318, 2020. @article{Berger2020, title = {Desulfurization process: understanding of the behaviour of the CuO/SBA-15 type SOx adsorbent in the presence of NO/NO2 and CO/CO2 flue gas environmental pollutants}, author = { M. Berger and S. Dorge and H. Nouali and D. Habermacher and E. Fiani and M. Vierling and M. Moliere and J. F. Brilhac and J. Patarin}, doi = {10.1016/j.cej.2019.123318}, year = {2020}, date = {2020-01-01}, journal = {Chemical Engineering Journal}, volume = {384}, pages = {123318}, abstract = {SOx (i.e. SO2 and SO3) compounds are known to be a major source of atmospheric pollution and to be responsible of adverse effects on the human health and on the environment. To reduce the SOx emissions, numerous abatement technologies were developed and applied. Nowadays, the most attractive one seems to be the process that use a regenerable SOx adsorbent. In this respect, a CuO (15 wt.%)/SBA-15 regenerable type SOx adsorbent has been developed. Under standard conditions (a gaseous mixture of N-2, SO2 and O-2), the adsorbent exhibits a stable adsorption capacity around 50 mg(SO2)/g(ads) along 10 cycles at 400 degrees C (for a 75 ppm of SO 2 exhaust concentration). The main aim of this work is to study the impact of various regulated pollutants such as CO, CO 2 , NO and NO2 on the SO2 adsorption capacity of the CuO (15 wt.%)/SBA-15 adsorbent. In the presence of CO and CO2, the SO2 adsorption performance of the CuO/SBA adsorbent is similar to the one observed under standard conditions. On the other hand, under NO and NO2 atmosphere, the dynamic and total adsorption capacities of the adsorbent are enhanced up to 25% and no deactivation occurs along the cycles. The increase may be related with the synergetic effect between NO2 and SO2 towards the sulphate formation. The CuO/SBA-15 adsorbent before and after multicycle SO2 adsorption in the presence of regulated pollutants and regeneration under 0.5 vol.% of H-2 have been characterized by XRD and N-2 physisorption. No significant structural and textural change is observed compared to the CuO/SBA-SO2 adsorbent.}, keywords = {}, pubstate = {published}, tppubtype = {article} } SOx (i.e. SO2 and SO3) compounds are known to be a major source of atmospheric pollution and to be responsible of adverse effects on the human health and on the environment. To reduce the SOx emissions, numerous abatement technologies were developed and applied. Nowadays, the most attractive one seems to be the process that use a regenerable SOx adsorbent. In this respect, a CuO (15 wt.%)/SBA-15 regenerable type SOx adsorbent has been developed. Under standard conditions (a gaseous mixture of N-2, SO2 and O-2), the adsorbent exhibits a stable adsorption capacity around 50 mg(SO2)/g(ads) along 10 cycles at 400 degrees C (for a 75 ppm of SO 2 exhaust concentration). The main aim of this work is to study the impact of various regulated pollutants such as CO, CO 2 , NO and NO2 on the SO2 adsorption capacity of the CuO (15 wt.%)/SBA-15 adsorbent. In the presence of CO and CO2, the SO2 adsorption performance of the CuO/SBA adsorbent is similar to the one observed under standard conditions. On the other hand, under NO and NO2 atmosphere, the dynamic and total adsorption capacities of the adsorbent are enhanced up to 25% and no deactivation occurs along the cycles. The increase may be related with the synergetic effect between NO2 and SO2 towards the sulphate formation. The CuO/SBA-15 adsorbent before and after multicycle SO2 adsorption in the presence of regulated pollutants and regeneration under 0.5 vol.% of H-2 have been characterized by XRD and N-2 physisorption. No significant structural and textural change is observed compared to the CuO/SBA-SO2 adsorbent. |
Paillaud, Jean-Louis; Gies, Hermann Editorial (Article de journal) Microporous and Mesoporous Materials, 291 , p. UNSP 109706, 2020. @article{Paillaud2020, title = {Editorial}, author = { Jean-Louis Paillaud and Hermann Gies}, doi = {10.1016/j.micromeso.2019.109706}, year = {2020}, date = {2020-01-01}, journal = {Microporous and Mesoporous Materials}, volume = {291}, pages = {UNSP 109706}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
2019 |
Maschowski, Christoph; Kruspan, Peter; Garra, Patxi; Arif, Ali Talib; Trouve, Gwenaelle; Giere, Reto Physicochemical and mineralogical characterization of biomass ash from different power plants in the Upper Rhine Region (Article de journal) Fuel, 258 , p. UNSP 116020, 2019. @article{Maschowski2019, title = {Physicochemical and mineralogical characterization of biomass ash from different power plants in the Upper Rhine Region}, author = { Christoph Maschowski and Peter Kruspan and Patxi Garra and Ali Talib Arif and Gwenaelle Trouve and Reto Giere}, doi = {10.1016/j.fuel.2019.116020}, year = {2019}, date = {2019-12-01}, journal = {Fuel}, volume = {258}, pages = {UNSP 116020}, abstract = {Bottom and fly ash samples from six biomass power plants with different power scales and various flue gas treatment strategies were collected and analyzed in regard to their mineralogical composition, and their bulk major and trace element contents, all of which are of concern for regulations on biomass ash for further utilization. Furthermore, individual ash particles were investigated by scanning electron microscopy to characterize their physicochemical microstructures. Thermal behavior of wood-pellet ash, i.e. decomposition processes and mineral transformations during combustion, was indicated by thermogravimetric analysis and X-ray diffraction. Results reveal extensive variation of physicochemical features across the different ash types: wood-chip fly ash from electrostatic precipitators mainly consisted of water-soluble salts, whereas wood-chip fly ash from cyclones contained predominantly cenospheres (hollow spherical fly ash particles) and higher heavy metal concentrations. In addition, the fuel type and admixture had influences on ash compositions; some fuels like Miscanthus straw require a liming agent such as calcium hydroxide to be admixed to prevent fouling, which is then predominantly found in the ash. Furthermore, boiler size had an influence on fly ash composition. Cadmium concentrations were elevated in some fly ash samples at levels of concern for further utilization, whereas concentrations of troublesome Cr(VI) were below the detection limit for all investigated ash samples. Other contaminating elements such as Ni, Pb and Zn were variable but below limit values. Results clearly show that the nature of biomass ash calls for careful analyses prior to further application as, e.g., cement clinker replacement material.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Bottom and fly ash samples from six biomass power plants with different power scales and various flue gas treatment strategies were collected and analyzed in regard to their mineralogical composition, and their bulk major and trace element contents, all of which are of concern for regulations on biomass ash for further utilization. Furthermore, individual ash particles were investigated by scanning electron microscopy to characterize their physicochemical microstructures. Thermal behavior of wood-pellet ash, i.e. decomposition processes and mineral transformations during combustion, was indicated by thermogravimetric analysis and X-ray diffraction. Results reveal extensive variation of physicochemical features across the different ash types: wood-chip fly ash from electrostatic precipitators mainly consisted of water-soluble salts, whereas wood-chip fly ash from cyclones contained predominantly cenospheres (hollow spherical fly ash particles) and higher heavy metal concentrations. In addition, the fuel type and admixture had influences on ash compositions; some fuels like Miscanthus straw require a liming agent such as calcium hydroxide to be admixed to prevent fouling, which is then predominantly found in the ash. Furthermore, boiler size had an influence on fly ash composition. Cadmium concentrations were elevated in some fly ash samples at levels of concern for further utilization, whereas concentrations of troublesome Cr(VI) were below the detection limit for all investigated ash samples. Other contaminating elements such as Ni, Pb and Zn were variable but below limit values. Results clearly show that the nature of biomass ash calls for careful analyses prior to further application as, e.g., cement clinker replacement material. |
Ghimbeu, Camelia Matei; Zhang, Biao; de Yuso, Alicia Martinez; Rety, Benedicte; Tarascon, Jean-Marie Valorizing low cost and renewable lignin as hard carbon for Na-ion batteries: Impact of lignin grade (Article de journal) Carbon, 153 , p. 634–647, 2019. @article{Ghimbeu2019, title = {Valorizing low cost and renewable lignin as hard carbon for Na-ion batteries: Impact of lignin grade}, author = { Camelia Matei Ghimbeu and Biao Zhang and Alicia Martinez de Yuso and Benedicte Rety and Jean-Marie Tarascon}, doi = {10.1016/j.carbon.2019.07.026}, year = {2019}, date = {2019-11-01}, journal = {Carbon}, volume = {153}, pages = {634--647}, abstract = {Lignin, the second most abundant biopolymer and rich in aromatic entities, is a by-product of paper industry and mainly burned to produce energy. Its commercialization for high-value added products remains largely unexplored today. Herein, we explored the preparation of hard carbon anodes for sodium-ion batteries using the two most common lignin grades, i.e, lignin kraft and lignin sulphonate. The lignin kraft hard carbon (LK-HC) shows small specific surface area (1.8 m(2)g(-1)) and a dense random like morphology while the latter lignin sulphonate hard carbon (LS-HC) presents a high surface area (180 m(2)g(-1)) and spherical particles containing macropores. Their electrochemical performances vs. Na+ revealed a steady capacity of 181 mAh g(-1) over cycling for LK-HC, as compared to a capacity of 205 mAh g(-1) for LS-HC which fades after 30 cycles due to an impurity-driven growth of a blocking solid electrolyte interphase (SEI). To circumvent this issue, an efficient washing procedure was successfully implemented enabling to obtain (LSW-HC) carbons which deliver a high and stable capacity (284 mAh g(-1)) along efficiency (78.1%). (C) 2019 Elsevier Ltd. All rights reserved.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Lignin, the second most abundant biopolymer and rich in aromatic entities, is a by-product of paper industry and mainly burned to produce energy. Its commercialization for high-value added products remains largely unexplored today. Herein, we explored the preparation of hard carbon anodes for sodium-ion batteries using the two most common lignin grades, i.e, lignin kraft and lignin sulphonate. The lignin kraft hard carbon (LK-HC) shows small specific surface area (1.8 m(2)g(-1)) and a dense random like morphology while the latter lignin sulphonate hard carbon (LS-HC) presents a high surface area (180 m(2)g(-1)) and spherical particles containing macropores. Their electrochemical performances vs. Na+ revealed a steady capacity of 181 mAh g(-1) over cycling for LK-HC, as compared to a capacity of 205 mAh g(-1) for LS-HC which fades after 30 cycles due to an impurity-driven growth of a blocking solid electrolyte interphase (SEI). To circumvent this issue, an efficient washing procedure was successfully implemented enabling to obtain (LSW-HC) carbons which deliver a high and stable capacity (284 mAh g(-1)) along efficiency (78.1%). (C) 2019 Elsevier Ltd. All rights reserved. |
Ng, Eng-Poh; Abdullahi, Haruna; Wong, Ka-Lun; Gines-Molina, Maria Jose; Maireles-Torres, Pedro; Rigolet, Severinne; Daou, Jean T; Chia, Stephen; Lee, Hooi Ling Ultrasmall Cs-AlMCM-41 basic catalysts: Effects of aluminum addition on their physico-chemical and catalytic properties (Article de journal) Microporous and Mesoporous Materials, 288 , p. UNSP 109599, 2019. @article{Ng2019f, title = {Ultrasmall Cs-AlMCM-41 basic catalysts: Effects of aluminum addition on their physico-chemical and catalytic properties}, author = { Eng-Poh Ng and Haruna Abdullahi and Ka-Lun Wong and Maria Jose Gines-Molina and Pedro Maireles-Torres and Severinne Rigolet and T. Jean Daou and Stephen Chia and Hooi Ling Lee}, doi = {10.1016/j.micromeso.2019.109599}, year = {2019}, date = {2019-11-01}, journal = {Microporous and Mesoporous Materials}, volume = {288}, pages = {UNSP 109599}, abstract = {In this study, ultra-small MCM-41 mesoporous solids (< 30 nm) were synthesized using colloidal silica and cesium hydroxide as cheap silica source and mineralize; respectively. Four samples with a SiO2/Al2O3 ratio of 5, 20, 30 and infinity (designated as CsM-5, CsM-20, CsM-30 and CsM-infinity, respectively) have been prepared. The effects of SiO2/Al2O3 ratio on the formation, physico-chemical and catalytic properties of CsMCM-41 nanoparticles were studied. The results show that incorporation of high content of Al atoms into the framework reduces the ordering of the mesostructure, and hence the porosity of the solids decreases. By using CsOH as mineralizer, the morphology and the size of CsMCM-41 were also tuned from 3-D nanospheres (CsM-5: 29 nm and CsM-20: 27 nm) to hollow nanospheres with very thin walls (CsM-30: 25 nm, CsM-infinity: 20 nm) when Al content was decreased. The basicity of CsMCM-41 nanoparticles was also affected by the AI and Cs contents. Hence, their catalytic behavior in the base-catalyzed reactions such as aldol condensation of heptanal with benzaldehyde, and Perkin condensation of benzaldehyde with acetic anhydride was evaluated under microwave heating conditions. CsM-20 displays the best catalytic activities among the samples studied, achieving 87.2% conversion and 78.4% selectivity to jasminaldehyde under optimum reaction conditions, while it also shows comparable catalytic performance as NaOH homogeneous catalyst in the Perkin condensation reaction under non-microwave instant heating conditions.}, keywords = {}, pubstate = {published}, tppubtype = {article} } In this study, ultra-small MCM-41 mesoporous solids (< 30 nm) were synthesized using colloidal silica and cesium hydroxide as cheap silica source and mineralize; respectively. Four samples with a SiO2/Al2O3 ratio of 5, 20, 30 and infinity (designated as CsM-5, CsM-20, CsM-30 and CsM-infinity, respectively) have been prepared. The effects of SiO2/Al2O3 ratio on the formation, physico-chemical and catalytic properties of CsMCM-41 nanoparticles were studied. The results show that incorporation of high content of Al atoms into the framework reduces the ordering of the mesostructure, and hence the porosity of the solids decreases. By using CsOH as mineralizer, the morphology and the size of CsMCM-41 were also tuned from 3-D nanospheres (CsM-5: 29 nm and CsM-20: 27 nm) to hollow nanospheres with very thin walls (CsM-30: 25 nm, CsM-infinity: 20 nm) when Al content was decreased. The basicity of CsMCM-41 nanoparticles was also affected by the AI and Cs contents. Hence, their catalytic behavior in the base-catalyzed reactions such as aldol condensation of heptanal with benzaldehyde, and Perkin condensation of benzaldehyde with acetic anhydride was evaluated under microwave heating conditions. CsM-20 displays the best catalytic activities among the samples studied, achieving 87.2% conversion and 78.4% selectivity to jasminaldehyde under optimum reaction conditions, while it also shows comparable catalytic performance as NaOH homogeneous catalyst in the Perkin condensation reaction under non-microwave instant heating conditions. |
Pavlova, Elizaveta R; Bagrov, Dmitry V; Monakhova, Kristina Z; Piryazev, Alexey A; Sokolova, Anastasia I; Ivanov, Dimitri A; Klinov, Dmitry V Tuning the properties of electrospun polylactide mats by ethanol treatment (Article de journal) Materials & Design, 181 , p. UNSP 108061, 2019. @article{Pavlova2019, title = {Tuning the properties of electrospun polylactide mats by ethanol treatment}, author = { Elizaveta R. Pavlova and Dmitry V. Bagrov and Kristina Z. Monakhova and Alexey A. Piryazev and Anastasia I. Sokolova and Dimitri A. Ivanov and Dmitry V. Klinov}, doi = {10.1016/j.matdes.2019.108061}, year = {2019}, date = {2019-11-01}, journal = {Materials & Design}, volume = {181}, pages = {UNSP 108061}, abstract = {In the present work, we analyzed the changes in structure and mechanical properties of electrospun PLA mats induced by ethanol treatment. The amorphous PLA mats gained elasticity when immersed into ethanol (the elongation at break increased from epsilon similar to 50% in air to epsilon similar to 280% in ethanol) and partly retained it after drying (epsilon similar to 110%). At the nanoscale, the ethanol treatment caused crimping of the fibers without crystallinity increase. Stretching of the electrospun mats in ethanol caused high alignment of the fibers (geometrical orientation factor f = 0.92) without the need for a special collector electrode such as a pair of blades, which yielded mats with geometrical orientation factor f = 0.71. The aligned mats prepared by stretching in ethanol caused contact guidance of HaCaT human keratinocytes and did not taint viability and proliferation rate of cells in comparison with the non-aligned ones. Our research demonstrates the tuning of electrospun mats properties by post-treatment without any modification of the chemical structure. (C) 2019 The Author(s). Published by Elsevier Ltd.}, keywords = {}, pubstate = {published}, tppubtype = {article} } In the present work, we analyzed the changes in structure and mechanical properties of electrospun PLA mats induced by ethanol treatment. The amorphous PLA mats gained elasticity when immersed into ethanol (the elongation at break increased from epsilon similar to 50% in air to epsilon similar to 280% in ethanol) and partly retained it after drying (epsilon similar to 110%). At the nanoscale, the ethanol treatment caused crimping of the fibers without crystallinity increase. Stretching of the electrospun mats in ethanol caused high alignment of the fibers (geometrical orientation factor f = 0.92) without the need for a special collector electrode such as a pair of blades, which yielded mats with geometrical orientation factor f = 0.71. The aligned mats prepared by stretching in ethanol caused contact guidance of HaCaT human keratinocytes and did not taint viability and proliferation rate of cells in comparison with the non-aligned ones. Our research demonstrates the tuning of electrospun mats properties by post-treatment without any modification of the chemical structure. (C) 2019 The Author(s). Published by Elsevier Ltd. |
Vigliaturo, Ruggero; Kehrli, Damaris; Garra, Patxi; Dieterlen, Alain; Trouve, Gwenaelle; Dietze, Volker; Wilson, Jonathan P; Giere, Reto Opaline phytoliths in Miscanthus sinensis and its cyclone ash from a biomass-combustion facility (Article de journal) Industrial Crops and Products, 139 , p. UNSP 111539, 2019. @article{Vigliaturo2019, title = {Opaline phytoliths in Miscanthus sinensis and its cyclone ash from a biomass-combustion facility}, author = { Ruggero Vigliaturo and Damaris Kehrli and Patxi Garra and Alain Dieterlen and Gwenaelle Trouve and Volker Dietze and Jonathan P. Wilson and Reto Giere}, doi = {10.1016/j.indcrop.2019.111539}, year = {2019}, date = {2019-11-01}, journal = {Industrial Crops and Products}, volume = {139}, pages = {UNSP 111539}, abstract = {Classifying biofuel feedstock crops on the basis of their inorganic constituents is needed to evaluate the critical role these components play during combustion and, later, when the ashes are used as fertilizer or as secondary raw material. Fluorescent and white-light microscopy, in combination with environmental scanning electron microscopy and energy-dispersive X-ray spectroscopy, was used to characterize phytoliths in Miscanthus sinensis, its dry extracts, and in the cyclone ash produced by the semi-industrial (400 kW) burning of this energy crop. The results show that the phytoliths are made of opal, SiO2 center dot n(H2O). X-ray powder diffraction data document that the SiO2-rich (31.7 wt%) cyclone ash consists of nearly 83 wt% amorphous material, which reflects the abundance of phytoliths in the studied materials. The cyclone ash also contains high amounts of some heavy metals, which suggests that Miscanthus sinensis is suitable for bioremediation of contaminated soils.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Classifying biofuel feedstock crops on the basis of their inorganic constituents is needed to evaluate the critical role these components play during combustion and, later, when the ashes are used as fertilizer or as secondary raw material. Fluorescent and white-light microscopy, in combination with environmental scanning electron microscopy and energy-dispersive X-ray spectroscopy, was used to characterize phytoliths in Miscanthus sinensis, its dry extracts, and in the cyclone ash produced by the semi-industrial (400 kW) burning of this energy crop. The results show that the phytoliths are made of opal, SiO2 center dot n(H2O). X-ray powder diffraction data document that the SiO2-rich (31.7 wt%) cyclone ash consists of nearly 83 wt% amorphous material, which reflects the abundance of phytoliths in the studied materials. The cyclone ash also contains high amounts of some heavy metals, which suggests that Miscanthus sinensis is suitable for bioremediation of contaminated soils. |
Deroche, Irena; Daou, Jean T; Picard, Cyril; Coasne, Benoit Reminiscent capillarity in subnanopores (Article de journal) Nature Communications, 10 , p. 4642, 2019. @article{Deroche2019, title = {Reminiscent capillarity in subnanopores}, author = { Irena Deroche and T. Jean Daou and Cyril Picard and Benoit Coasne}, doi = {10.1038/s41467-019-12418-9}, year = {2019}, date = {2019-10-01}, journal = {Nature Communications}, volume = {10}, pages = {4642}, abstract = {Fluids in large and small pores display different behaviors with a crossover described through the concept of critical capillarity. Here we report experimental and simulation data for various siliceous zeolites and adsorbates that show unexpected reminiscent capillarity for such nanoporous materials. For pore sizes D exceeding the fluid molecule size, the filling pressures p are found to follow a generic behavior k(B)T In p similar to gamma/rho D where gamma and rho are the fluid surface tension and density. This result is rationalized by showing that the filling chemical potential for such ultra-small pores is the sum of an adsorption energy and a capillary energy that remains meaningful even for severe confinements. A phenomenological model, based on Derjaguin's formalism to bridge macroscopic and molecular theories for condensation in porous materials, is developed to account for the behavior of fluids confined down to the molecular scale from simple parameters.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Fluids in large and small pores display different behaviors with a crossover described through the concept of critical capillarity. Here we report experimental and simulation data for various siliceous zeolites and adsorbates that show unexpected reminiscent capillarity for such nanoporous materials. For pore sizes D exceeding the fluid molecule size, the filling pressures p are found to follow a generic behavior k(B)T In p similar to gamma/rho D where gamma and rho are the fluid surface tension and density. This result is rationalized by showing that the filling chemical potential for such ultra-small pores is the sum of an adsorption energy and a capillary energy that remains meaningful even for severe confinements. A phenomenological model, based on Derjaguin's formalism to bridge macroscopic and molecular theories for condensation in porous materials, is developed to account for the behavior of fluids confined down to the molecular scale from simple parameters. |
Dietlin, Celine; Trinh, Thanh Tam; Schweizer, Stephane; Graff, Bernadette; Morlet-Savary, Fabrice; Noirot, Pierre-Antoine; Lalevee, Jacques Rational Design of Acyldiphenylphosphine Oxides as Photoinitiators of Radical Polymerization (Article de journal) Macromolecules, 52 (20), p. 7886–7893, 2019. @article{Dietlin2019, title = {Rational Design of Acyldiphenylphosphine Oxides as 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 = {10.1021/acs.macromol.9b01724}, year = {2019}, date = {2019-10-01}, journal = {Macromolecules}, volume = {52}, number = {20}, pages = {7886--7893}, abstract = {Some efficient acylphosphine oxides have been used for many years as photoinitiators of radical polymerization. As very few new acylphosphine oxide compounds have been proposed these past years for the radical polymerization of methacrylates, the aim of this work is to use molecular modeling to select potentially reactive compounds before their synthesis to see whether acyldiphenylphosphine oxide (ADPO) molecules can compete or even work better than commercial and well-established acylphosphine oxides. Two of the common acylphosphine oxides, TPO-L and BAPO, used in industrial applications will be taken as references in this work, while new ADPO will be evaluated in photopolymerization reaction initiated upon LED at 395 nm. In fact, the photopolymerization industrial technology is evolving from the use of an energy-consuming Hg lamp toward the use of safer LEDs working typically in the 385-405 nm range. At least two of the compounds are competing or working better than the well-established systems in a reference benchmarked acrylic resin, evidencing the importance of molecular modeling for the design of new photoinitiators before their synthesis.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Some efficient acylphosphine oxides have been used for many years as photoinitiators of radical polymerization. As very few new acylphosphine oxide compounds have been proposed these past years for the radical polymerization of methacrylates, the aim of this work is to use molecular modeling to select potentially reactive compounds before their synthesis to see whether acyldiphenylphosphine oxide (ADPO) molecules can compete or even work better than commercial and well-established acylphosphine oxides. Two of the common acylphosphine oxides, TPO-L and BAPO, used in industrial applications will be taken as references in this work, while new ADPO will be evaluated in photopolymerization reaction initiated upon LED at 395 nm. In fact, the photopolymerization industrial technology is evolving from the use of an energy-consuming Hg lamp toward the use of safer LEDs working typically in the 385-405 nm range. At least two of the compounds are competing or working better than the well-established systems in a reference benchmarked acrylic resin, evidencing the importance of molecular modeling for the design of new photoinitiators before their synthesis. |
Arfi, Rim Ben; Karoui, Sarra; Mougin, Karine; Ghorbal, Achraf Cetyltrimethylammonium bromide-treated Phragmites australis powder as novel polymeric adsorbent for hazardous Eriochrome Black T removal from aqueous solutions (Article de journal) Polymer Bulletin, 76 (10), p. 5077–5102, 2019. @article{BenArfi2019, title = {Cetyltrimethylammonium bromide-treated Phragmites australis powder as novel polymeric adsorbent for hazardous Eriochrome Black T removal from aqueous solutions}, author = { Rim Ben Arfi and Sarra Karoui and Karine Mougin and Achraf Ghorbal}, doi = {10.1007/s00289-018-2648-8}, year = {2019}, date = {2019-10-01}, journal = {Polymer Bulletin}, volume = {76}, number = {10}, pages = {5077--5102}, abstract = {The potential of cetyltrimethylammonium bromide-treated Phragmites australis powder (CTAB-PA) as a novel polymeric sorbent for Eriochrome Black T (EBT) removal was studied. CTAB impregnation process increased adsorption sites availability that led to a better interaction of EBT dye and CTAB-PA. CTAB impregnation process increased the PA monolayer adsorption capacity from 57.14 to 89.93 mg g(-1). Adsorption data were modeled using chemical reaction-based kinetic models (pseudo-first-order, pseudo-second-order, and Elovich models) and diffusion-based kinetic models (Weber-Morris and Boyd models). EBT sorption kinetics could be described by the pseudo-second-order model having film diffusion as the main rate-limiting step. Adsorption data for both adsorbents were fitted to Langmuir, Freundlich, Temkin, and Dubinin-Radushkevich models, and best fitting was obtained with Langmuir model. Thermodynamic functions indicated that EBT adsorption onto PA and CTAB-PA was an exothermic and physical process. CTAB-PA burning behavior showed that this novel adsorbent can be considered as flame-retarding material. Adsorption-desorption experiments revealed that CTAB-PA could be reused up to five cycles with recovery percentage values maintained higher than 71%. CTAB-PA, a low-cost, durable, flame-retarding, and reusable material, was found to be an attractive candidate for EBT removal from water.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The potential of cetyltrimethylammonium bromide-treated Phragmites australis powder (CTAB-PA) as a novel polymeric sorbent for Eriochrome Black T (EBT) removal was studied. CTAB impregnation process increased adsorption sites availability that led to a better interaction of EBT dye and CTAB-PA. CTAB impregnation process increased the PA monolayer adsorption capacity from 57.14 to 89.93 mg g(-1). Adsorption data were modeled using chemical reaction-based kinetic models (pseudo-first-order, pseudo-second-order, and Elovich models) and diffusion-based kinetic models (Weber-Morris and Boyd models). EBT sorption kinetics could be described by the pseudo-second-order model having film diffusion as the main rate-limiting step. Adsorption data for both adsorbents were fitted to Langmuir, Freundlich, Temkin, and Dubinin-Radushkevich models, and best fitting was obtained with Langmuir model. Thermodynamic functions indicated that EBT adsorption onto PA and CTAB-PA was an exothermic and physical process. CTAB-PA burning behavior showed that this novel adsorbent can be considered as flame-retarding material. Adsorption-desorption experiments revealed that CTAB-PA could be reused up to five cycles with recovery percentage values maintained higher than 71%. CTAB-PA, a low-cost, durable, flame-retarding, and reusable material, was found to be an attractive candidate for EBT removal from water. |
Eren, Tugce Nur; Lalevee, Jacques; Avci, Duygu Bisphosphonic Acid-Functionalized Water-Soluble Photoinitiators (Article de journal) Macromolecular Chemistry and Physics, 220 (19), p. 1900268, 2019. @article{Eren2019a, title = {Bisphosphonic Acid-Functionalized Water-Soluble Photoinitiators}, author = { Tugce Nur Eren and Jacques Lalevee and Duygu Avci}, doi = {10.1002/macp.201900268}, year = {2019}, date = {2019-10-01}, journal = {Macromolecular Chemistry and Physics}, volume = {220}, number = {19}, pages = {1900268}, abstract = {The first bisphosphonic acid-functionalized benzophenone (BP) and thioxanthone (TX) photoinitiators (PIs), BPBP and TXBP, are synthesized as a new class of water-soluble PIs for free radical polymerization. BPBP shows excellent solubility (28 g L-1) in water at ambient temperature, compared to TXBP (0.05 g L-1) and also the commercial PI Irgacure 2959 (5 g L-1). BPBP and TXBP show UV-vis absorption at approximate to 260 (epsilon = 12912) and 405 (epsilon = 3314) nm in water. Photopolymerization results demonstrate that they can successfully initiate the photopolymerization of poly(ethylene glycol) diacrylate (M-n = 250 D) in the presence of bis-(4-tert-butylphenyl)-iodonium hexafluorophosphate (Iod). The photochemical mechanisms are investigated by electron-spin resonance-spin trapping, fluorescence, and steady-state photolysis techniques.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The first bisphosphonic acid-functionalized benzophenone (BP) and thioxanthone (TX) photoinitiators (PIs), BPBP and TXBP, are synthesized as a new class of water-soluble PIs for free radical polymerization. BPBP shows excellent solubility (28 g L-1) in water at ambient temperature, compared to TXBP (0.05 g L-1) and also the commercial PI Irgacure 2959 (5 g L-1). BPBP and TXBP show UV-vis absorption at approximate to 260 (epsilon = 12912) and 405 (epsilon = 3314) nm in water. Photopolymerization results demonstrate that they can successfully initiate the photopolymerization of poly(ethylene glycol) diacrylate (M-n = 250 D) in the presence of bis-(4-tert-butylphenyl)-iodonium hexafluorophosphate (Iod). The photochemical mechanisms are investigated by electron-spin resonance-spin trapping, fluorescence, and steady-state photolysis techniques. |
Gerard, Violaine; Ay, Emel; Graff, Bernadette; Morlet-Savary, Fabrice; Galopin, Christophe; Mutilangi, William; Lalevee, Jacques Ascorbic Acid Derivatives as Potential Substitutes for Ascorbic Acid To Reduce Color Degradation of Drinks Containing Ascorbic Acid and Anthocyanins from Natural Extracts. (Article de journal) Journal of agricultural and food chemistry, 67 (43), p. 12061–12071, 2019. @article{Gerard2019a, title = {Ascorbic Acid Derivatives as Potential Substitutes for Ascorbic Acid To Reduce Color Degradation of Drinks Containing Ascorbic Acid and Anthocyanins from Natural Extracts.}, author = { Violaine Gerard and Emel Ay and Bernadette Graff and Fabrice Morlet-Savary and Christophe Galopin and William Mutilangi and Jacques Lalevee}, doi = {10.1021/acs.jafc.9b05049}, year = {2019}, date = {2019-10-01}, journal = {Journal of agricultural and food chemistry}, volume = {67}, number = {43}, pages = {12061--12071}, abstract = {Ascorbic acid is widely used in the food industry as a source of vitamin C or as antioxidant. However, it degrades quickly in beverages at acidic pH and can accelerate the degradation of anthocyanins, natural dyes used in beverages, leading to a loss of color. In this work, we investigated the possibility to replace ascorbic acid by ascorbic acid derivatives to prevent its degradation effect on anthocyanins from natural extracts (black carrot, grape juice, and purple sweet potato). For this, the thermal and photolytic stabilities under air and under N2 of ascorbic acid (as reference) and of some ascorbic acid derivatives (3-O-ethyl-l-ascorbic acid, 2-O-alpha-d-glucopyranosyl-l-ascorbic acid, l-ascorbic acid 2-phosphate sesquimagnesium salt hydrate, l-ascorbyl 2,6-dibutyrate, glyceryl ascorbate, (+)-5,6-O-isopropylidene-l-ascorbic acid), soluble in aqueous model beverages, were studied alone and in the presence of anthocyanins from the natural extracts in citrate buffer at pH 3. The stability was followed by UV-visible spectrometry. To extend the investigation, some properties of the ascorbic acid derivatives (pKa, oxidation potential, bond dissociation energy, ionization potential) were also determined. Moreover, the addition of chlorogenic acid was examined to further stabilize the mixture of anthocyanins with 2-O-alpha-d-glucopyranosyl-l-ascorbic acid, a promising ascorbic acid derivative.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Ascorbic acid is widely used in the food industry as a source of vitamin C or as antioxidant. However, it degrades quickly in beverages at acidic pH and can accelerate the degradation of anthocyanins, natural dyes used in beverages, leading to a loss of color. In this work, we investigated the possibility to replace ascorbic acid by ascorbic acid derivatives to prevent its degradation effect on anthocyanins from natural extracts (black carrot, grape juice, and purple sweet potato). For this, the thermal and photolytic stabilities under air and under N2 of ascorbic acid (as reference) and of some ascorbic acid derivatives (3-O-ethyl-l-ascorbic acid, 2-O-alpha-d-glucopyranosyl-l-ascorbic acid, l-ascorbic acid 2-phosphate sesquimagnesium salt hydrate, l-ascorbyl 2,6-dibutyrate, glyceryl ascorbate, (+)-5,6-O-isopropylidene-l-ascorbic acid), soluble in aqueous model beverages, were studied alone and in the presence of anthocyanins from the natural extracts in citrate buffer at pH 3. The stability was followed by UV-visible spectrometry. To extend the investigation, some properties of the ascorbic acid derivatives (pKa, oxidation potential, bond dissociation energy, ionization potential) were also determined. Moreover, the addition of chlorogenic acid was examined to further stabilize the mixture of anthocyanins with 2-O-alpha-d-glucopyranosyl-l-ascorbic acid, a promising ascorbic acid derivative. |
Thiebault, Thomas; Brendle, Jocelyne; Auge, Gregoire; Limousy, Lionel Zwitterionic-surfactant modified LAPONITE (R) s for removal of ions (Cs+, Sr2+ and Co2+) from aqueous solutions as a sustainable recovery method for radionuclides from aqueous wastes (Article de journal) Green Chemistry, 21 (18), p. 5118–5127, 2019. @article{Thiebault2019, title = {Zwitterionic-surfactant modified LAPONITE (R) s for removal of ions (Cs+, Sr2+ and Co2+) from aqueous solutions as a sustainable recovery method for radionuclides from aqueous wastes}, author = { Thomas Thiebault and Jocelyne Brendle and Gregoire Auge and Lionel Limousy}, doi = {10.1039/c9gc02243k}, year = {2019}, date = {2019-09-01}, journal = {Green Chemistry}, volume = {21}, number = {18}, pages = {5118--5127}, abstract = {The synthesis of zwitterionic-surfactant modified LAPONITE (R) s (LAP-CBs) was investigated as a function of the surfactant loading in order to obtain a suitable adsorbent for the removal of Co2+, Sr2+ and Cs+ ions from aqueous solutions. The proper adsorption of surfactant was characterized by several techniques that emphasized the modification of the surfactant distribution between the interlayer space and the surface of LAPONITE (R) (LAP), with increasing loading of surfactant. The organophilic character of the obtained LAP-CBs strongly affected their affinity for the targeted contaminants. The adsorption of Sr2+ was lower on LAP-CBs in comparison to that on LAP, while the adsorption of Co2+ and Cs+ was strongly improved. The competition between Sr2+ and Cs+ was important for LAP-CBs adsorption, whereas no competition was found when using LAP, indicating that the adsorption mechanism differed depending on the adsorbent. The desorption of contaminants was performed in various solutions and confirmed these mechanisms. Whereas Cs+ and Sr2+ were adsorbed through cation exchange onto LAP-CBs, as highlighted by a significant desorption in saline solution, the desorption of Co2+ from LAP-CBs was very poor whatever the composition of the release solution, indicating adsorption by complexation. Finally, increasing the load of surfactant decreased the adsorption capacity of the adsorbent for all of the investigated contaminants. The arrangement of the surfactant, within the interlayer space or on the surface of LAP, was therefore a critical factor when considering the potential of this material to durably remove radionuclides from low-level radioactive wastewaters.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The synthesis of zwitterionic-surfactant modified LAPONITE (R) s (LAP-CBs) was investigated as a function of the surfactant loading in order to obtain a suitable adsorbent for the removal of Co2+, Sr2+ and Cs+ ions from aqueous solutions. The proper adsorption of surfactant was characterized by several techniques that emphasized the modification of the surfactant distribution between the interlayer space and the surface of LAPONITE (R) (LAP), with increasing loading of surfactant. The organophilic character of the obtained LAP-CBs strongly affected their affinity for the targeted contaminants. The adsorption of Sr2+ was lower on LAP-CBs in comparison to that on LAP, while the adsorption of Co2+ and Cs+ was strongly improved. The competition between Sr2+ and Cs+ was important for LAP-CBs adsorption, whereas no competition was found when using LAP, indicating that the adsorption mechanism differed depending on the adsorbent. The desorption of contaminants was performed in various solutions and confirmed these mechanisms. Whereas Cs+ and Sr2+ were adsorbed through cation exchange onto LAP-CBs, as highlighted by a significant desorption in saline solution, the desorption of Co2+ from LAP-CBs was very poor whatever the composition of the release solution, indicating adsorption by complexation. Finally, increasing the load of surfactant decreased the adsorption capacity of the adsorbent for all of the investigated contaminants. The arrangement of the surfactant, within the interlayer space or on the surface of LAP, was therefore a critical factor when considering the potential of this material to durably remove radionuclides from low-level radioactive wastewaters. |
Liu, Yinghui; Rety, Benedicte; Ghimbeu, Camelia Matei; Soucaze-Guillous, Benoit; Taberna, Pierre-Louis; Simon, Patrice Understanding ageing mechanisms of porous carbons in non-aqueous electrolytes for supercapacitors applications (Article de journal) Journal of Power Sources, 434 , p. 226734, 2019. @article{Liu2019, title = {Understanding ageing mechanisms of porous carbons in non-aqueous electrolytes for supercapacitors applications}, author = { Yinghui Liu and Benedicte Rety and Camelia Matei Ghimbeu and Benoit Soucaze-Guillous and Pierre-Louis Taberna and Patrice Simon}, doi = {10.1016/j.jpowsour.2019.226734}, year = {2019}, date = {2019-09-01}, journal = {Journal of Power Sources}, volume = {434}, pages = {226734}, abstract = {Two activated porous carbon powders with different surface functional groups content have been electrochemically polarized in tetraethylammonium tetrafluoborate (Et4NBF4) in acetonitrile electrolyte to study their ageing mechanism as supercapacitor electrodes. Temperature-programmed desorption coupled with mass spectrometry technique (TPD-MS) is used to track the change of carbon surface chemistry - surface functional groups and/or adsorption of degradation products occurring upon polarizations. A potentiostatic study of the carbons in a two-compartment cell unveil the catalytic role of water in the ageing mechanism. Combining these results with our previous work, we propose different scenarios to depict the ageing mechanisms of the two carbons. For carbon A, hydrolysis of BF4- at the positive electrode leads to carbon oxidation together with soluble poly-acetonitrile oligomer occurred from reaction between B-4(center dot) radicals and acetonitrile. Ageing mechanism is also assumed to set off with the hydrolysis of BF4- for carbon B; but, in here the formed oligomers react with acid functional groups present at the carbon surface to form a protective, passive-like layer at both positive and negative electrodes which hampers a further electrode ageing.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Two activated porous carbon powders with different surface functional groups content have been electrochemically polarized in tetraethylammonium tetrafluoborate (Et4NBF4) in acetonitrile electrolyte to study their ageing mechanism as supercapacitor electrodes. Temperature-programmed desorption coupled with mass spectrometry technique (TPD-MS) is used to track the change of carbon surface chemistry - surface functional groups and/or adsorption of degradation products occurring upon polarizations. A potentiostatic study of the carbons in a two-compartment cell unveil the catalytic role of water in the ageing mechanism. Combining these results with our previous work, we propose different scenarios to depict the ageing mechanisms of the two carbons. For carbon A, hydrolysis of BF4- at the positive electrode leads to carbon oxidation together with soluble poly-acetonitrile oligomer occurred from reaction between B-4(center dot) radicals and acetonitrile. Ageing mechanism is also assumed to set off with the hydrolysis of BF4- for carbon B; but, in here the formed oligomers react with acid functional groups present at the carbon surface to form a protective, passive-like layer at both positive and negative electrodes which hampers a further electrode ageing. |
Bouchoum, Hayat; Benmoussa, Dounia; Jada, Amane; Tahiri, Mohamed; Cherkaoui, Omar Synthesis of amidoximated polyacrylonitrile fibers and its use as adsorbent for Cr (VI) ions removal from aqueous solutions (Article de journal) Environmental Progress & Sustainable Energy, 38 (5), p. UNSP 13196, 2019. @article{Bouchoum2019, title = {Synthesis of amidoximated polyacrylonitrile fibers and its use as adsorbent for Cr (VI) ions removal from aqueous solutions}, author = { Hayat Bouchoum and Dounia Benmoussa and Amane Jada and Mohamed Tahiri and Omar Cherkaoui}, doi = {10.1002/ep.13196}, year = {2019}, date = {2019-09-01}, journal = {Environmental Progress & Sustainable Energy}, volume = {38}, number = {5}, pages = {UNSP 13196}, abstract = {Functionalized fibers, especially polyacrylonitrile fibers (PANF), have attracted wide interest as an effective and economical material for environment and water protection. In this study, polyacrylonitrile fibers modified with hydroxylamine hydrochloride were used as an adsorbent to remove hexavalent chromium ions from aqueous solutions. The novelty of the present study compared to the literature is the functionalization of polyacrylonitrile fibers surface by optimizing cost and energy while achieving a yield fast removal rate and high adsorption capacity of hexavalent chromium from aqueous solutions. The amidoximated polyacrylonitrile fibers were characterized using Fourier Transform InfraRed spectroscopy (FTIR) and Scanning Electron Microscopy (SEM). The results confirmed the success of polyacrylonitrile fibers modification. The adsorption capacity was evaluated by investigating the effect of initial pH solution ranging from 2.0 to 7.0, the adsorbent dose varied from 0.05 to 0.25 g, the initial Cr (VI) concentration range was (5-70 mg g(-1)), the temperature varied from 5 to 60 degrees C, and the contact time ranged from 0 to 180 min. We have used the Langmuir and Freundlich adsorption models to describe the equilibrium sorption data. The maximum adsorption capacity estimated using the Langmuir model reached 32. 57 mg g(-1) under optimal conditions. The thermodynamic parameters (Delta G, Delta H, and Delta S) were also determined. In addition, the adsorbent showed a desorption rate of Cr (VI) up to 92% with 0.5 mol of NaOH, which can be reused for three adsorption-desorption cycles. The overall data showed the efficiency of amidoximated polyacrylonitrile fibers in removing Cr (VI) from aqueous solutions. (c) 2019 American Institute of Chemical Engineers Environ Prog, 38:e13146, 2019}, keywords = {}, pubstate = {published}, tppubtype = {article} } Functionalized fibers, especially polyacrylonitrile fibers (PANF), have attracted wide interest as an effective and economical material for environment and water protection. In this study, polyacrylonitrile fibers modified with hydroxylamine hydrochloride were used as an adsorbent to remove hexavalent chromium ions from aqueous solutions. The novelty of the present study compared to the literature is the functionalization of polyacrylonitrile fibers surface by optimizing cost and energy while achieving a yield fast removal rate and high adsorption capacity of hexavalent chromium from aqueous solutions. The amidoximated polyacrylonitrile fibers were characterized using Fourier Transform InfraRed spectroscopy (FTIR) and Scanning Electron Microscopy (SEM). The results confirmed the success of polyacrylonitrile fibers modification. The adsorption capacity was evaluated by investigating the effect of initial pH solution ranging from 2.0 to 7.0, the adsorbent dose varied from 0.05 to 0.25 g, the initial Cr (VI) concentration range was (5-70 mg g(-1)), the temperature varied from 5 to 60 degrees C, and the contact time ranged from 0 to 180 min. We have used the Langmuir and Freundlich adsorption models to describe the equilibrium sorption data. The maximum adsorption capacity estimated using the Langmuir model reached 32. 57 mg g(-1) under optimal conditions. The thermodynamic parameters (Delta G, Delta H, and Delta S) were also determined. In addition, the adsorbent showed a desorption rate of Cr (VI) up to 92% with 0.5 mol of NaOH, which can be reused for three adsorption-desorption cycles. The overall data showed the efficiency of amidoximated polyacrylonitrile fibers in removing Cr (VI) from aqueous solutions. (c) 2019 American Institute of Chemical Engineers Environ Prog, 38:e13146, 2019 |
Wang, Dengxia; Kaya, Kerem; Garra, Patxi; Fouassier, Jean-Pierre; Graff, Bernadette; Yagci, Yusuf; Lalevee, Jacques Sulfonium salt based charge transfer complexes as dual thermal and photochemical polymerization initiators for composites and 3D printing (Article de journal) Polymer Chemistry, 10 (34), p. 4690–4698, 2019. @article{Wang2019c, title = {Sulfonium salt based charge transfer complexes as dual thermal and photochemical polymerization initiators for composites and 3D printing}, author = { Dengxia Wang and Kerem Kaya and Patxi Garra and Jean-Pierre Fouassier and Bernadette Graff and Yusuf Yagci and Jacques Lalevee}, doi = {10.1039/c9py00913b}, year = {2019}, date = {2019-09-01}, journal = {Polymer Chemistry}, volume = {10}, number = {34}, pages = {4690--4698}, abstract = {Charge transfer complexes (CTCs) exhibit excellent initiating abilities as safe photo, thermal, or photo/thermal dual initiators, which cannot be achieved by classical initiators. New dual initiators based on a phenacyl sulfonium salt (ITXPhenS) acceptor and selected donors capable of initiating both thermal and photochemical polymerizations are investigated. Excellent dual initiating ability and long storage stability were examined by RT-FTIR and DSC experiments. The formations of the CTCs were confirmed by UV-vis spectroscopic investigations and MOC (Molecular Orbital Calculations). The application of the newly developed initiating system in laser writing experiments at 405 nm shows excellent spatial resolution performance. High-tech composites with tack free surfaces can be easily fabricated by employing these kinds of CTCs via fast photochemical curing of the surface associated with a thermal curing in depth. Both carbon fibers and glass fiber composites were prepared.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Charge transfer complexes (CTCs) exhibit excellent initiating abilities as safe photo, thermal, or photo/thermal dual initiators, which cannot be achieved by classical initiators. New dual initiators based on a phenacyl sulfonium salt (ITXPhenS) acceptor and selected donors capable of initiating both thermal and photochemical polymerizations are investigated. Excellent dual initiating ability and long storage stability were examined by RT-FTIR and DSC experiments. The formations of the CTCs were confirmed by UV-vis spectroscopic investigations and MOC (Molecular Orbital Calculations). The application of the newly developed initiating system in laser writing experiments at 405 nm shows excellent spatial resolution performance. High-tech composites with tack free surfaces can be easily fabricated by employing these kinds of CTCs via fast photochemical curing of the surface associated with a thermal curing in depth. Both carbon fibers and glass fiber composites were prepared. |
Gibot, Pierre; Miesch, Quentin; Bach, Arnaud; Schnell, Fabien; Gadiou, Roger; Spitzer, Denis Mechanical Desensitization of an Al/WO3 Nanothermite by Means of Carbonaceous Coatings Derived from Carbohydrates (Article de journal) C-journal of Carbon Research, 5 (3), p. 37, 2019. @article{Gibot2019, title = {Mechanical Desensitization of an Al/WO3 Nanothermite by Means of Carbonaceous Coatings Derived from Carbohydrates}, author = { Pierre Gibot and Quentin Miesch and Arnaud Bach and Fabien Schnell and Roger Gadiou and Denis Spitzer}, doi = {10.3390/c5030037}, year = {2019}, date = {2019-09-01}, journal = {C-journal of Carbon Research}, volume = {5}, number = {3}, pages = {37}, abstract = {Nanothermites show great developmental promise in the near future in civilian, military and aerospace applications due to their tuneable reactive properties (ignition delay time, combustion velocity and pressure release). However, the high mechanical sensitivities of some of these energetic nanocomposites can make transportation and handling of them hazardous. Here, a mechanical desensitization (shock and friction) of an Al/WO3 nanothermite is successfully obtained by means of carbon adding through the pyrolysis of naturally occurring molecules (carbohydrates). The combustion behaviour of the carbon-based energetic mixtures were also evaluated and a respectable reactivity has been evidenced.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Nanothermites show great developmental promise in the near future in civilian, military and aerospace applications due to their tuneable reactive properties (ignition delay time, combustion velocity and pressure release). However, the high mechanical sensitivities of some of these energetic nanocomposites can make transportation and handling of them hazardous. Here, a mechanical desensitization (shock and friction) of an Al/WO3 nanothermite is successfully obtained by means of carbon adding through the pyrolysis of naturally occurring molecules (carbohydrates). The combustion behaviour of the carbon-based energetic mixtures were also evaluated and a respectable reactivity has been evidenced. |
Nita, Cristina; Fullenwarth, Julien; Monconduit, Laure; Vidal, Loic; Ghimbeu, Camelia Matei Influence of carbon characteristics on Sb/carbon nanocomposites formation and performances in Na-ion batteries (Article de journal) Materials Today Energy, 13 , p. 221–232, 2019. @article{Nita2019a, title = {Influence of carbon characteristics on Sb/carbon nanocomposites formation and performances in Na-ion batteries}, author = { Cristina Nita and Julien Fullenwarth and Laure Monconduit and Loic Vidal and Camelia Matei Ghimbeu}, doi = {10.1016/j.mtener.2019.05.009}, year = {2019}, date = {2019-09-01}, journal = {Materials Today Energy}, volume = {13}, pages = {221--232}, abstract = {The impact of carbon characteristics (structure, porosity and surface chemistry) on the Sb/Carbon composites formation and electrochemical performances in Na-ion batteries is investigated herein. Mesoporous and non-porous hard carbon heated at different temperatures were used to support Sb nanoparticles prepared via a ball-milling/thermal reduction synthesis approach. The mesoporous carbon presenting higher surface area and oxygen functional groups induce the formation of small Sb nanoparticles (<5 nm) well dispersed in the carbon network. For the hard carbon, the increase in the annealing temperature from 1100 to 1500 degrees C leads to more organized structure but lower porosity and surface functionalities having as consequence the increase of Sb nanoparticle size and the particle agglomeration. The best electrochemical performances vs. Na were achieved for hard carbon/Sb composite treated at 1100 degrees C which combines several advantages like dispersed Sb nanoparticle, low surface area and good conductivity (360 mAh g(-1) after 200 cycles). Regarding the long-term capacity retention, for all materials a drastic decay was observed starting to 300 cycles and associated to the Sb particle size agglomeration and growth during repeated charge/discharge cycles and amorphization of Sb particles as demonstrated by post-mortem analyses. (C) 2019 Elsevier Ltd. All rights reserved.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The impact of carbon characteristics (structure, porosity and surface chemistry) on the Sb/Carbon composites formation and electrochemical performances in Na-ion batteries is investigated herein. Mesoporous and non-porous hard carbon heated at different temperatures were used to support Sb nanoparticles prepared via a ball-milling/thermal reduction synthesis approach. The mesoporous carbon presenting higher surface area and oxygen functional groups induce the formation of small Sb nanoparticles (<5 nm) well dispersed in the carbon network. For the hard carbon, the increase in the annealing temperature from 1100 to 1500 degrees C leads to more organized structure but lower porosity and surface functionalities having as consequence the increase of Sb nanoparticle size and the particle agglomeration. The best electrochemical performances vs. Na were achieved for hard carbon/Sb composite treated at 1100 degrees C which combines several advantages like dispersed Sb nanoparticle, low surface area and good conductivity (360 mAh g(-1) after 200 cycles). Regarding the long-term capacity retention, for all materials a drastic decay was observed starting to 300 cycles and associated to the Sb particle size agglomeration and growth during repeated charge/discharge cycles and amorphization of Sb particles as demonstrated by post-mortem analyses. (C) 2019 Elsevier Ltd. All rights reserved. |
Wang, Dengxia; Garra, Patxi; Fouassier, Jean Pierre; Graff, Bernadette; Yagci, Yusuf; Lalevee, Jacques Indole-based charge transfer complexes as versatile dual thermal and photochemical polymerization initiators for 3D printing and composites (Article de journal) Polymer Chemistry, 10 (36), p. 4991–5000, 2019. @article{Wang2019a, title = {Indole-based charge transfer complexes as versatile dual thermal and photochemical polymerization initiators for 3D printing and composites}, author = { Dengxia Wang and Patxi Garra and Jean Pierre Fouassier and Bernadette Graff and Yusuf Yagci and Jacques Lalevee}, doi = {10.1039/c9py00878k}, year = {2019}, date = {2019-09-01}, journal = {Polymer Chemistry}, volume = {10}, number = {36}, pages = {4991--5000}, abstract = {Charge Transfer Complexes (CTCs) have recently been featured as new dual photo/thermal initiators, with attractive initiating features, such as in situ formation, high stability, spatiotemporal control, highly efficient process at room temperature (for the photochemical mode), reduced emissions of volatile organic compounds (VOCs) and high robustness in additive manufacturing and composite manufacturing. Extending the concept, in the present work, a series of CTCs formed between indoles (donors) and iodonium salt (acceptor) are investigated as safer and more stable dual thermal and photochemical free radical polymerization (FRP) initiators for benchmarked methacrylates. The formation of the CTCs is evaluated theoretically by Molecular Orbital (MO) calculations and experimentally using UV-vis spectroscopy. Remarkably, due to the in situ formation, safer storage ability as thermal initiators compared to traditional thermal initiators is demonstrated. As an additive manufacturing proof of concept, laser write experiments @405 nm show excellent spatial resolution performances. Dual approaches (photo/thermal curing) were also used to efficiently initiate both polymerization processes for the curing of glass fiber or carbon fiber composites, e.g. fast curing by light of the surface associated with a dark thermal curing in depth.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Charge Transfer Complexes (CTCs) have recently been featured as new dual photo/thermal initiators, with attractive initiating features, such as in situ formation, high stability, spatiotemporal control, highly efficient process at room temperature (for the photochemical mode), reduced emissions of volatile organic compounds (VOCs) and high robustness in additive manufacturing and composite manufacturing. Extending the concept, in the present work, a series of CTCs formed between indoles (donors) and iodonium salt (acceptor) are investigated as safer and more stable dual thermal and photochemical free radical polymerization (FRP) initiators for benchmarked methacrylates. The formation of the CTCs is evaluated theoretically by Molecular Orbital (MO) calculations and experimentally using UV-vis spectroscopy. Remarkably, due to the in situ formation, safer storage ability as thermal initiators compared to traditional thermal initiators is demonstrated. As an additive manufacturing proof of concept, laser write experiments @405 nm show excellent spatial resolution performances. Dual approaches (photo/thermal curing) were also used to efficiently initiate both polymerization processes for the curing of glass fiber or carbon fiber composites, e.g. fast curing by light of the surface associated with a dark thermal curing in depth. |
Trinh, Thi Kim Hoang; Schrodj, Gautier; Rigolet, Severinne; Pinaud, Julien; Lacroix-Desmazes, Patrick; Pichavant, Loic; Heroguez, Valerie; Chemtob, Abraham Combining a ligand photogenerator and a Ru precatalyst: a photoinduced approach to cross-linked ROMP polymer films (Article de journal) Rsc Advances, 9 (48), p. 27789–27799, 2019. @article{Trinh2019b, title = {Combining a ligand photogenerator and a Ru precatalyst: a photoinduced approach to cross-linked ROMP polymer films}, author = { Thi Kim Hoang Trinh and Gautier Schrodj and Severinne Rigolet and Julien Pinaud and Patrick Lacroix-Desmazes and Loic Pichavant and Valerie Heroguez and Abraham Chemtob}, doi = {10.1039/c9ra05831a}, year = {2019}, date = {2019-09-01}, journal = {Rsc Advances}, volume = {9}, number = {48}, pages = {27789--27799}, abstract = {Although metathesis photoinduced catalysis is now well established, there is little development in thin film preparation using photochemically activated ring-opening metathesis polymerization (ROMP). Herein, a N-heterocyclic carbene (NHC) photogenerator (1,3-bis(mesityl)imidazolium tetraphenylborate) is combined with an inactive metathesis catalyst ([RuCl2(p-cymene)](2)) to generate under UV irradiation an active catalyst (p-cymene)RuCl2 (NHC), that is capable of producing in a single step cross-linked copolymer films by ROMP of norbornene with dicyclopentadiene. The study shows that the photoinitiated catalytic system can be optimized by increasing the yield of photogenerated NHC through a sensitizer (2-isopropylthioxanthone), and by choosing [RuI2(p-cymene)](2) as precatalyst to provide a long-term photolatency. The cross-linked polymer structure is investigated by a range of techniques including gel content measurement, FT-IR and solid-state C-13 NMR spectroscopy, TGA and DSC, which reveal a cross-linking mechanism proceeding through both metathesis and olefin coupling.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Although metathesis photoinduced catalysis is now well established, there is little development in thin film preparation using photochemically activated ring-opening metathesis polymerization (ROMP). Herein, a N-heterocyclic carbene (NHC) photogenerator (1,3-bis(mesityl)imidazolium tetraphenylborate) is combined with an inactive metathesis catalyst ([RuCl2(p-cymene)](2)) to generate under UV irradiation an active catalyst (p-cymene)RuCl2 (NHC), that is capable of producing in a single step cross-linked copolymer films by ROMP of norbornene with dicyclopentadiene. The study shows that the photoinitiated catalytic system can be optimized by increasing the yield of photogenerated NHC through a sensitizer (2-isopropylthioxanthone), and by choosing [RuI2(p-cymene)](2) as precatalyst to provide a long-term photolatency. The cross-linked polymer structure is investigated by a range of techniques including gel content measurement, FT-IR and solid-state C-13 NMR spectroscopy, TGA and DSC, which reveal a cross-linking mechanism proceeding through both metathesis and olefin coupling. |
Valverde-Gonzalez, Antonio; Marchal, Gwendoline; Maya, Eva M; Iglesias, Marta A step forward in solvent knitting strategies: ruthenium and gold phosphine complex polymerization results in effective heterogenized catalysts (Article de journal) Catalysis Science & Technology, 9 (17), p. 4552–4560, 2019. @article{Valverde-Gonzalez2019, title = {A step forward in solvent knitting strategies: ruthenium and gold phosphine complex polymerization results in effective heterogenized catalysts}, author = { Antonio Valverde-Gonzalez and Gwendoline Marchal and Eva M. Maya and Marta Iglesias}, doi = {10.1039/c9cy00776h}, year = {2019}, date = {2019-09-01}, journal = {Catalysis Science & Technology}, volume = {9}, number = {17}, pages = {4552--4560}, abstract = {Porous polymers based on ruthenium and gold triphenylphosphine complexes (KPhos(Ru), KPhos(Ru)Bi, KPhos(AuCl) and KPhos(AuNTf2)) were prepared via a cost-effective solvent knitting method with [RuHClCO(PPh3)(3)] or AuXPPh3 (X = Cl, NTf2) as single monomers or combined with biphenyl, which represents a further approach to obtain heterogenized catalysts. The resulting materials mainly preserve the metal coordination environment of their parent complexes, are stable up to 350 degrees C and have reasonable surface areas (250-300 m(2) g(-1) for KPhos(Ru)-polymers). KPhos(Ru)s selectively catalyze the imination of alcohols in the presence of base and the results for KPhos(Au)s show they are effective for the intermolecular hydration and hydroamination of alkynes. These materials can be reused several times without significant loss of activity. This novel and simple method affords heterogenized catalysts that combine the reactivity and selectivity of their homogeneous counterparts with the stability and reusability of a heterogeneous framework.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Porous polymers based on ruthenium and gold triphenylphosphine complexes (KPhos(Ru), KPhos(Ru)Bi, KPhos(AuCl) and KPhos(AuNTf2)) were prepared via a cost-effective solvent knitting method with [RuHClCO(PPh3)(3)] or AuXPPh3 (X = Cl, NTf2) as single monomers or combined with biphenyl, which represents a further approach to obtain heterogenized catalysts. The resulting materials mainly preserve the metal coordination environment of their parent complexes, are stable up to 350 degrees C and have reasonable surface areas (250-300 m(2) g(-1) for KPhos(Ru)-polymers). KPhos(Ru)s selectively catalyze the imination of alcohols in the presence of base and the results for KPhos(Au)s show they are effective for the intermolecular hydration and hydroamination of alkynes. These materials can be reused several times without significant loss of activity. This novel and simple method affords heterogenized catalysts that combine the reactivity and selectivity of their homogeneous counterparts with the stability and reusability of a heterogeneous framework. |
Kirschner, Julie; Szillat, Florian; Bouzrati-Zerelli, Mariem; Becht, Jean-Michel; Klee, Joachim E; Lalevee, Jacques Iodonium sulfonates as high-performance coinitiators and additives for CQ-based systems: Toward aromatic amine-free photoinitiating systems (Article de journal) Journal of Polymer Science Part A-polymer Chemistry, 57 (15), p. 1664–1669, 2019. @article{Kirschner2019b, title = {Iodonium sulfonates as high-performance coinitiators and additives for CQ-based systems: Toward aromatic amine-free photoinitiating systems}, author = { Julie Kirschner and Florian Szillat and Mariem Bouzrati-Zerelli and Jean-Michel Becht and Joachim E. Klee and Jacques Lalevee}, doi = {10.1002/pola.29431}, year = {2019}, date = {2019-08-01}, journal = {Journal of Polymer Science Part A-polymer Chemistry}, volume = {57}, number = {15}, pages = {1664--1669}, abstract = {Iodonium sulfonates are proposed here as a new class of high-performance coinitiators for camphorquinone (CQ)-based systems for the polymerization of methacrylates under blue light irradiation. When combined with CQ, the new proposed coinitiators present excellent polymerization performances and are excellent candidates for the replacement of tertiary aromatic amines subjected to toxicological concerns in the well-established CQ/amine photoinitiating system (PIS). Remarkably, good bleaching properties are obtained after polymerization. The use of the new PIS for dental adhesives is also investigated. (c) 2019 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2019}, keywords = {}, pubstate = {published}, tppubtype = {article} } Iodonium sulfonates are proposed here as a new class of high-performance coinitiators for camphorquinone (CQ)-based systems for the polymerization of methacrylates under blue light irradiation. When combined with CQ, the new proposed coinitiators present excellent polymerization performances and are excellent candidates for the replacement of tertiary aromatic amines subjected to toxicological concerns in the well-established CQ/amine photoinitiating system (PIS). Remarkably, good bleaching properties are obtained after polymerization. The use of the new PIS for dental adhesives is also investigated. (c) 2019 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2019 |
Fakir, Abdellah Ait El; Anfar, Zakaria; Benafqir, Mohamed; Jada, Amane; Alem, Noureddine El Journal of Chemical Technology and Biotechnology, 94 (8), p. 2609–2620, 2019. @article{ElFakir2019, title = {Polyaniline coated hematite sand supported on graphene oxide (HS@PANI-GO) as a new magnetic material for advanced catalytic oxidation based on sulfate radicals: optimization using response surface methodology}, author = { Abdellah Ait El Fakir and Zakaria Anfar and Mohamed Benafqir and Amane Jada and Noureddine El Alem}, doi = {10.1002/jctb.6070}, year = {2019}, date = {2019-08-01}, journal = {Journal of Chemical Technology and Biotechnology}, volume = {94}, number = {8}, pages = {2609--2620}, abstract = {BACKGROUND We report here on the synthesis of a new magnetic and natural material: polyaniline coated hematite sand supported on graphene oxide (HS@PANI-GO) which was used as an heterogeneous catalyst to activate persulfate (PS) for aqueous solution Orange G (OG) degradation. RESULTS The characterization results have revealed that the hematite sand is rich in iron oxide, and the inorganic particles were well coated with polyaniline and successfully dispersed in graphene oxide. Further, catalytic oxidation experiments demonstrated that HS@PANI-GO material exhibited high activity in the PS activation for the OG degradation. It was found that complete OG removal from aqueous solution was achieved in 90 min at natural pH. In addition, the influence of various reaction conditions such as temperature, concentration of PS, catalyst dose, pH and decomposition time over the HS@PAN-GO/PS system were investigated and optimized. The catalyst HS@PAN-GO could be recycled easily by a magnet with good reusability. Finally, the effects of various parameters such as PS concentration, catalyst dose, initial OG concentration, and contact time, were investigated using the response surface methodology (RSM). It transpires that the experimental elimination of OG is 98.14%, as obtained under optimal conditions, was very close to the predicted value (96.58%) determined by RSM. CONCLUSION This study provides a promising way for the activation of green oxidant 'PS', by using a new magnetic composite suited for environmental remediation and oxidation catalysis. (c) 2019 Society of Chemical Industry}, keywords = {}, pubstate = {published}, tppubtype = {article} } BACKGROUND We report here on the synthesis of a new magnetic and natural material: polyaniline coated hematite sand supported on graphene oxide (HS@PANI-GO) which was used as an heterogeneous catalyst to activate persulfate (PS) for aqueous solution Orange G (OG) degradation. RESULTS The characterization results have revealed that the hematite sand is rich in iron oxide, and the inorganic particles were well coated with polyaniline and successfully dispersed in graphene oxide. Further, catalytic oxidation experiments demonstrated that HS@PANI-GO material exhibited high activity in the PS activation for the OG degradation. It was found that complete OG removal from aqueous solution was achieved in 90 min at natural pH. In addition, the influence of various reaction conditions such as temperature, concentration of PS, catalyst dose, pH and decomposition time over the HS@PAN-GO/PS system were investigated and optimized. The catalyst HS@PAN-GO could be recycled easily by a magnet with good reusability. Finally, the effects of various parameters such as PS concentration, catalyst dose, initial OG concentration, and contact time, were investigated using the response surface methodology (RSM). It transpires that the experimental elimination of OG is 98.14%, as obtained under optimal conditions, was very close to the predicted value (96.58%) determined by RSM. CONCLUSION This study provides a promising way for the activation of green oxidant 'PS', by using a new magnetic composite suited for environmental remediation and oxidation catalysis. (c) 2019 Society of Chemical Industry |
Akhouairi, Siham; Ouachtak, Hassan; Addi, Abdelaziz Ait; Jada, Amane; Douch, Jamaa Natural Sawdust as Adsorbent for the Eriochrome Black T Dye Removal from Aqueous Solution (Article de journal) Water Air and Soil Pollution, 230 (8), p. 181, 2019. @article{Akhouairi2019, title = {Natural Sawdust as Adsorbent for the Eriochrome Black T Dye Removal from Aqueous Solution}, author = { Siham Akhouairi and Hassan Ouachtak and Abdelaziz Ait Addi and Amane Jada and Jamaa Douch}, doi = {10.1007/s11270-019-4234-6}, year = {2019}, date = {2019-08-01}, journal = {Water Air and Soil Pollution}, volume = {230}, number = {8}, pages = {181}, abstract = {This paper deals with the adsorption of an anionic dye, Eriochrome Black T (EBT), from aqueous solutions onto sawdust, which is a natural, eco-friendly, widespread, and a low-cost bio sorbent. The aim of the work is to append values to the wood industry waste. Thus, sawdust was used as adsorbent in both batch reactor (BR) and fixed bed column (FBC), and various operating parameters influencing the adsorption process were investigated. The kinetic and the equilibrium adsorption results were found to agree with, respectively, the prediction of the pseudo-second-order equation and the Langmuir model. This latter allowed also the determination of the maximum EBT dye adsorbed amount, which was found to be about 40.96mg EBT per gram of sawdust at pH=4, corresponding to % dye removal of about 80%. In addition, the influence of various parameters on the dye adsorption, such as the adsorbent dose, the aqueous phase pH, and the initial dye concentration, was also examined. In batch experiments, The EBT adsorbed amount was found to increase either by increasing the amount of sawdust or by decreasing the aqueous phase pH, whereas, in the fixed bed column, the EBT retention was found to increase by decreasing the flow rate of the dye through the column. The overall data indicate that the EBT adsorption is mainly governed by the electrostatic interactions occurring between the adsorbent material and the dye.}, keywords = {}, pubstate = {published}, tppubtype = {article} } This paper deals with the adsorption of an anionic dye, Eriochrome Black T (EBT), from aqueous solutions onto sawdust, which is a natural, eco-friendly, widespread, and a low-cost bio sorbent. The aim of the work is to append values to the wood industry waste. Thus, sawdust was used as adsorbent in both batch reactor (BR) and fixed bed column (FBC), and various operating parameters influencing the adsorption process were investigated. The kinetic and the equilibrium adsorption results were found to agree with, respectively, the prediction of the pseudo-second-order equation and the Langmuir model. This latter allowed also the determination of the maximum EBT dye adsorbed amount, which was found to be about 40.96mg EBT per gram of sawdust at pH=4, corresponding to % dye removal of about 80%. In addition, the influence of various parameters on the dye adsorption, such as the adsorbent dose, the aqueous phase pH, and the initial dye concentration, was also examined. In batch experiments, The EBT adsorbed amount was found to increase either by increasing the amount of sawdust or by decreasing the aqueous phase pH, whereas, in the fixed bed column, the EBT retention was found to increase by decreasing the flow rate of the dye through the column. The overall data indicate that the EBT adsorption is mainly governed by the electrostatic interactions occurring between the adsorbent material and the dye. |
Conder, J; Vaulot, C; Marino, C; Villevieille, C; Ghimbeu, C M Chitin and Chitosan-Structurally Related Precursors of Dissimilar Hard Carbons for Na-Ion Battery (Article de journal) Acs Applied Energy Materials, 2 (7), p. 4841–4852, 2019. @article{Conder2019, title = {Chitin and Chitosan-Structurally Related Precursors of Dissimilar Hard Carbons for Na-Ion Battery}, author = { J. Conder and C. Vaulot and C. Marino and C. Villevieille and C. M. Ghimbeu}, doi = {10.1021/acsaem.9b00545}, year = {2019}, date = {2019-07-01}, journal = {Acs Applied Energy Materials}, volume = {2}, number = {7}, pages = {4841--4852}, abstract = {Hard carbons (HCs) prepared from renewable precursors are promising cost-effective electrode-material candidates for the application in Na-ion battery. Usually these materials are derived from cellulose. Here, however, we demonstrate that other polysaccharides, such as chitin and chitosan, can be as well up-and-coming parent materials of HCs. Despite structural similarities, thermal decomposition of these two biopolymers proceeds differently, contributing to the discrepancies in physicochemical properties of resulting HCs. Although chitin- and chitosan-derived HCs have comparable d-spacings and crystallite sizes, solid-state pyrolysis of the former biopolymer leads to micromesoporous material with significant specific surface area, while that of chitosan yields nonporous carbon. Despite that, both materials deliver similar initial specific charge of 280 mAh g(-1) (at C/10 rate), and their electrochemical performance starts to diverge only upon longer cycling at higher rate. With time, inorganic contaminants present in chitosan-derived HC presumably delay the diffusion of Na ions to and within the electrode and slow the rate of electrochemical reactions, eventually triggering polarization buildup. Further optimization of the chitosan-derived HC through acid treatment enables unblocking some of the micropores and increasing the carbon content in this material, therefore enhancing its active surface area and suppressing continuous fading of the specific charge.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Hard carbons (HCs) prepared from renewable precursors are promising cost-effective electrode-material candidates for the application in Na-ion battery. Usually these materials are derived from cellulose. Here, however, we demonstrate that other polysaccharides, such as chitin and chitosan, can be as well up-and-coming parent materials of HCs. Despite structural similarities, thermal decomposition of these two biopolymers proceeds differently, contributing to the discrepancies in physicochemical properties of resulting HCs. Although chitin- and chitosan-derived HCs have comparable d-spacings and crystallite sizes, solid-state pyrolysis of the former biopolymer leads to micromesoporous material with significant specific surface area, while that of chitosan yields nonporous carbon. Despite that, both materials deliver similar initial specific charge of 280 mAh g(-1) (at C/10 rate), and their electrochemical performance starts to diverge only upon longer cycling at higher rate. With time, inorganic contaminants present in chitosan-derived HC presumably delay the diffusion of Na ions to and within the electrode and slow the rate of electrochemical reactions, eventually triggering polarization buildup. Further optimization of the chitosan-derived HC through acid treatment enables unblocking some of the micropores and increasing the carbon content in this material, therefore enhancing its active surface area and suppressing continuous fading of the specific charge. |
Garra, Patxi; Dietlin, Celine; Morlet-Savary, Fabrice; Dumur, Frederic; Gigmes, Didier; Fouassier, Jean-Pierre; Lalevee, Jacques Redox two-component initiated free radical and cationic polymerizations: Concepts, reactions and applications (Article de journal) Progress in Polymer Science, 94 , p. 33–56, 2019. @article{Garra2019a, title = {Redox two-component initiated free radical and cationic polymerizations: Concepts, reactions and applications}, author = { Patxi Garra and Celine Dietlin and Fabrice Morlet-Savary and Frederic Dumur and Didier Gigmes and Jean-Pierre Fouassier and Jacques Lalevee}, doi = {10.1016/j.progpolymsci.2019.04.003}, year = {2019}, date = {2019-07-01}, journal = {Progress in Polymer Science}, volume = {94}, pages = {33--56}, abstract = {Redox polymerizations are of huge importance throughout academic and industrial polymer science. Many authors propose the reaction of reducing (Red) and oxidizing (Ox) agents to accelerate/initiate radical or cationic polymerizations. As a result of activation energies typically below 80 kJ/mol, such reactions can occur under mild conditions, e.g., at room temperature, with reduced energy consumptions and robust in applications, such as the fabrication of composites. However, a clear definition of redox polymerization can only be found in reviews dealing with redox free radical polymerizations (FRP) published twenty years ago (or more). Therefore, a fresh and broader update is provided here for more recent work. The concepts involved when the Redand Oxagents (constituting the redox initiating system) are mixed under mild conditions are presented, followed by a discussion of the redox FRP initiating systems in bulk. Initiating systems dealing with the redox cationic polymerization (CP) are reviewed, and parallels between conventional FRP/CP and controlled polymerizations, in which redox systems are used, is provided. Many redox agents are useful in both modes. Finally, dual-cure (redox/photochemical; redox dual FRP/CP) systems is presented and selected applications are reviewed. Altogether, the state of the art for redox two-component polymerizations is provided, along with some perspectives. (C) 2019 Elsevier B.V. All rights reserved.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Redox polymerizations are of huge importance throughout academic and industrial polymer science. Many authors propose the reaction of reducing (Red) and oxidizing (Ox) agents to accelerate/initiate radical or cationic polymerizations. As a result of activation energies typically below 80 kJ/mol, such reactions can occur under mild conditions, e.g., at room temperature, with reduced energy consumptions and robust in applications, such as the fabrication of composites. However, a clear definition of redox polymerization can only be found in reviews dealing with redox free radical polymerizations (FRP) published twenty years ago (or more). Therefore, a fresh and broader update is provided here for more recent work. The concepts involved when the Redand Oxagents (constituting the redox initiating system) are mixed under mild conditions are presented, followed by a discussion of the redox FRP initiating systems in bulk. Initiating systems dealing with the redox cationic polymerization (CP) are reviewed, and parallels between conventional FRP/CP and controlled polymerizations, in which redox systems are used, is provided. Many redox agents are useful in both modes. Finally, dual-cure (redox/photochemical; redox dual FRP/CP) systems is presented and selected applications are reviewed. Altogether, the state of the art for redox two-component polymerizations is provided, along with some perspectives. (C) 2019 Elsevier B.V. All rights reserved. |
Prevost, Victor; Anselme, Karine; Gallet, Olivier; Hindie, Mathilde; Petithory, Tatiana; Valentin, Jules; Veuillet, Mathieu; Ploux, Lydie Real-Time Imaging of Bacteria/Osteoblast Dynamic Coculture on Bone Implant Material in an in Vitro Postoperative Contamination Model (Article de journal) Acs Biomaterials Science & Engineering, 5 (7), p. 3260–3269, 2019. @article{Prevost2019, title = {Real-Time Imaging of Bacteria/Osteoblast Dynamic Coculture on Bone Implant Material in an in Vitro Postoperative Contamination Model}, author = { Victor Prevost and Karine Anselme and Olivier Gallet and Mathilde Hindie and Tatiana Petithory and Jules Valentin and Mathieu Veuillet and Lydie Ploux}, doi = {10.1021/acsbiomaterials.9b00050}, year = {2019}, date = {2019-07-01}, journal = {Acs Biomaterials Science & Engineering}, volume = {5}, number = {7}, pages = {3260--3269}, abstract = {Biomedical implants are an important part of evolving modern medicine but have a potential drawback in the form of postoperative pathogenic infection. Accordingly, the "race for surface" combat between invasive bacteria and host cells determines the fate of implants. Hence, proper in vitro systems are required to assess effective strategies to avoid infection. In this study, we developed a real time observation model, mimicking postoperative contamination, designed to follow E. coli proliferation on a titanium surface occupied by human osteoblastic progenitor cells (STRO). This model allowed us to monitor E. coli invasion of human cells on titanium surfaces coated and uncoated with fibronectin. We showed that the surface colonization of bacteria is significantly enhanced on fibronectin coated surfaces irrespective of whether areas were uncovered or covered with human cells. We further revealed that bacterial colonization of the titanium surfaces is enhanced in coculture with STRO cells. Finally, this coculture system provides a comprehensive system to describe in vitro and in situ bacterial and human cells and their localization but also to target biological mechanisms involved in adhesion as well as in interactions with surfaces, thanks to fluorescent labeling. This system is thus an efficient method for studies related to the design and function of new biomaterials.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Biomedical implants are an important part of evolving modern medicine but have a potential drawback in the form of postoperative pathogenic infection. Accordingly, the "race for surface" combat between invasive bacteria and host cells determines the fate of implants. Hence, proper in vitro systems are required to assess effective strategies to avoid infection. In this study, we developed a real time observation model, mimicking postoperative contamination, designed to follow E. coli proliferation on a titanium surface occupied by human osteoblastic progenitor cells (STRO). This model allowed us to monitor E. coli invasion of human cells on titanium surfaces coated and uncoated with fibronectin. We showed that the surface colonization of bacteria is significantly enhanced on fibronectin coated surfaces irrespective of whether areas were uncovered or covered with human cells. We further revealed that bacterial colonization of the titanium surfaces is enhanced in coculture with STRO cells. Finally, this coculture system provides a comprehensive system to describe in vitro and in situ bacterial and human cells and their localization but also to target biological mechanisms involved in adhesion as well as in interactions with surfaces, thanks to fluorescent labeling. This system is thus an efficient method for studies related to the design and function of new biomaterials. |
Qin, Zhengxing; Pinard, Ludovic; Benghalem, Mohammed Amine; Daou, Jean T; Melinte, Georgian; Ersen, Ovidiu; Asahina, Shunsuke; Gilson, Jean-Pierre; Valtchev, Valentin Preparation of Single-Crystal "House-of-Cards"-like ZSM-5 and Their Performance in Ethanol-to-Hydrocarbon Conversion (Article de journal) Chemistry of Materials, 31 (13), p. 4639–4648, 2019. @article{Qin2019, title = {Preparation of Single-Crystal "House-of-Cards"-like ZSM-5 and Their Performance in Ethanol-to-Hydrocarbon Conversion}, author = { Zhengxing Qin and Ludovic Pinard and Mohammed Amine Benghalem and T. Jean Daou and Georgian Melinte and Ovidiu Ersen and Shunsuke Asahina and Jean-Pierre Gilson and Valentin Valtchev}, doi = {10.1021/acs.chemmater.8b04970}, year = {2019}, date = {2019-07-01}, journal = {Chemistry of Materials}, volume = {31}, number = {13}, pages = {4639--4648}, abstract = {The present study reports the unbiased chemical etching of micron-sized ZSM-5 crystals with an NH4F solution, resulting in house-of-cards-like single crystals containing large rectangular cavities surrounded by thin (15-30 nm), flat, and highly crystalline walls. The formation of such house-of-cards-like architecture is a result of the preferential extraction of misoriented nanocrystalline domains followed by the uniform dissolution of the remaining part of the crystal. The characteristic features of NH4F-treated zeolites are the retention of framework composition (Si/Al) and Bronsted acidity, high crystallinity, a moderate increase in the external surface area, and increased accessibility to their active sites. Such a combination produces zeolite catalysts with superior performances (activity, stability, and coke resistance) in the ethanol-to-hydrocarbon conversion. The physicochemical properties of this newly engineered zeolite are compared to those of a hierarchical zeolite obtained by caustic leaching and zeolite nanosheets synthesized with a bifunctional template, a diquaternary ammonium-type surfactant.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The present study reports the unbiased chemical etching of micron-sized ZSM-5 crystals with an NH4F solution, resulting in house-of-cards-like single crystals containing large rectangular cavities surrounded by thin (15-30 nm), flat, and highly crystalline walls. The formation of such house-of-cards-like architecture is a result of the preferential extraction of misoriented nanocrystalline domains followed by the uniform dissolution of the remaining part of the crystal. The characteristic features of NH4F-treated zeolites are the retention of framework composition (Si/Al) and Bronsted acidity, high crystallinity, a moderate increase in the external surface area, and increased accessibility to their active sites. Such a combination produces zeolite catalysts with superior performances (activity, stability, and coke resistance) in the ethanol-to-hydrocarbon conversion. The physicochemical properties of this newly engineered zeolite are compared to those of a hierarchical zeolite obtained by caustic leaching and zeolite nanosheets synthesized with a bifunctional template, a diquaternary ammonium-type surfactant. |
Ghali, Mariem; Brahmi, Chaima; Benltifa, Mahmoud; Dumur, Frederic; Duval, Sylvain; Simonnet-Jegat, Corine; Morlet-Savary, Fabrice; Jellali, Salah; Bousselmi, Latifa; Lalevee, Jacques New hybrid polyoxometalate/polymer composites for photodegradation of eosin dye (Article de journal) Journal of Polymer Science Part A-polymer Chemistry, 57 (14), p. 1538–1549, 2019. @article{Ghali2019, title = {New hybrid polyoxometalate/polymer composites for photodegradation of eosin dye}, author = { Mariem Ghali and Chaima Brahmi and Mahmoud Benltifa and Frederic Dumur and Sylvain Duval and Corine Simonnet-Jegat and Fabrice Morlet-Savary and Salah Jellali and Latifa Bousselmi and Jacques Lalevee}, doi = {10.1002/pola.29416}, year = {2019}, date = {2019-07-01}, journal = {Journal of Polymer Science Part A-polymer Chemistry}, volume = {57}, number = {14}, pages = {1538--1549}, abstract = {New polyoxometalate (POM)/polymer hybrid composites were prepared by photopolymerization under mild conditions for suitable photocatalytic processes. Polyoxometalates were incorporated in special photosensitive resins, which were photopolymerized under visible light to obtain new materials with photocatalytic activity for dye removal. The synthesized composites were characterized by real-time FT-IR, and the photocatalytic ability was investigated on Eosin-Y removal using photolysis under near UV irradiation. Interestingly, the polyoxometalates keep their photocatalytic properties, while incorporated into the polymeric matrix since very high conversion rates of Eosin-Y were achieved. Indeed, degradation efficiencies of about 98% and 93% were registered when using H3PMo12O40/polymer and 94% for SiMo12O40(IPh2)(4)/polymer composites, respectively. These first results reported in this article show that the new synthesized POM/polymer composites could be considered as promising materials for green and more suitable organic dye removal from aqueous solutions. (c) 2019 Wiley Periodicals, Inc.}, keywords = {}, pubstate = {published}, tppubtype = {article} } New polyoxometalate (POM)/polymer hybrid composites were prepared by photopolymerization under mild conditions for suitable photocatalytic processes. Polyoxometalates were incorporated in special photosensitive resins, which were photopolymerized under visible light to obtain new materials with photocatalytic activity for dye removal. The synthesized composites were characterized by real-time FT-IR, and the photocatalytic ability was investigated on Eosin-Y removal using photolysis under near UV irradiation. Interestingly, the polyoxometalates keep their photocatalytic properties, while incorporated into the polymeric matrix since very high conversion rates of Eosin-Y were achieved. Indeed, degradation efficiencies of about 98% and 93% were registered when using H3PMo12O40/polymer and 94% for SiMo12O40(IPh2)(4)/polymer composites, respectively. These first results reported in this article show that the new synthesized POM/polymer composites could be considered as promising materials for green and more suitable organic dye removal from aqueous solutions. (c) 2019 Wiley Periodicals, Inc. |
Cremoux, T; Batonneau-Gener, I; Moissette, A; Paillaud, J - L; Hureau, M; Ligner, E; Morais, C; Laforge, S; Marichal, C; Nouali, H Influence of framework Si/Al ratio and topology on electron transfers in zeolites (Article de journal) Physical Chemistry Chemical Physics, 21 (27), p. 14892–14903, 2019. @article{Cremoux2019, title = {Influence of framework Si/Al ratio and topology on electron transfers in zeolites}, author = { T. Cremoux and I. Batonneau-Gener and A. Moissette and J. -. L. Paillaud and M. Hureau and E. Ligner and C. Morais and S. Laforge and C. Marichal and H. Nouali}, doi = {10.1039/c9cp01166h}, year = {2019}, date = {2019-07-01}, journal = {Physical Chemistry Chemical Physics}, volume = {21}, number = {27}, pages = {14892--14903}, abstract = {H-ZSM-5 and H-*BEA zeolites were hydrothermally synthesized with different Si/Al ratios (similar to 12 to similar to 40). The physico-chemical properties of the resulting materials were fully characterized by several techniques (NMR, BET, PXRD, and pyridine thermal desorption followed by infrared spectroscopy). To assess the effect of the zeolite type and Si/Al ratio on sample reactivity, the charge separation processes between the zeolite framework and the adsorbed trans-stilbene (t-St) molecule were investigated by UV-visible diffuse reflectance and FT-Raman spectroscopy. The UV-visible absorption spectra obtained after t-St adsorption show a clear difference depending on the zeolite type. It appears that the radical cation resulting from t-St spontaneous ionization is more stabilized in the MFI-type framework than in the *BEA topology. However, the amount and stability of the electron-hole pair resulting from the radical cation evolution to a charge transfer complex are more important in the *BEA zeolite. On the basis of the experimental results and physico-chemical properties of the sample, we found that the radical cation and the electron-hole stabilities are strongly dependent on the amount of hexacoordinated aluminum (Al-(VI)) and more precisely on their environment, i.e. the distance between Bronsted sites and strong Lewis sites or Bronsted Strong Lewis Pairs (BSLPs).}, keywords = {}, pubstate = {published}, tppubtype = {article} } H-ZSM-5 and H-*BEA zeolites were hydrothermally synthesized with different Si/Al ratios (similar to 12 to similar to 40). The physico-chemical properties of the resulting materials were fully characterized by several techniques (NMR, BET, PXRD, and pyridine thermal desorption followed by infrared spectroscopy). To assess the effect of the zeolite type and Si/Al ratio on sample reactivity, the charge separation processes between the zeolite framework and the adsorbed trans-stilbene (t-St) molecule were investigated by UV-visible diffuse reflectance and FT-Raman spectroscopy. The UV-visible absorption spectra obtained after t-St adsorption show a clear difference depending on the zeolite type. It appears that the radical cation resulting from t-St spontaneous ionization is more stabilized in the MFI-type framework than in the *BEA topology. However, the amount and stability of the electron-hole pair resulting from the radical cation evolution to a charge transfer complex are more important in the *BEA zeolite. On the basis of the experimental results and physico-chemical properties of the sample, we found that the radical cation and the electron-hole stabilities are strongly dependent on the amount of hexacoordinated aluminum (Al-(VI)) and more precisely on their environment, i.e. the distance between Bronsted sites and strong Lewis sites or Bronsted Strong Lewis Pairs (BSLPs). |
Khiari, Besma; Jeguirim, Mejdi; Limousy, Lionel; Bennici, Simona Biomass derived chars for energy applications (Article de journal) Renewable & Sustainable Energy Reviews, 108 , p. 253–273, 2019. @article{Khiari2019b, title = {Biomass derived chars for energy applications}, author = { Besma Khiari and Mejdi Jeguirim and Lionel Limousy and Simona Bennici}, doi = {10.1016/j.rser.2019.03.057}, year = {2019}, date = {2019-07-01}, journal = {Renewable & Sustainable Energy Reviews}, volume = {108}, pages = {253--273}, abstract = {Biomass-derived chars present energy density values close to those of fossil fuels and therefore they are good candidates in electricity or heat production plants with only minor drawbacks compared to fossil fuels. Even if co-firing seems the most attractive solution for near-term applications, processes based on combustion and gasification (which are competing in dependence of the need of heat or electricity) are receiving renewed attention. Thanks to their high carbon content, and their high specific surface area and developed porous structure, biomass-derived chars can be treated and converted into activated carbons and applied in many different field (as energy storage materials for gaseous fuels, mainly hydrogen and methane, or as electrodes). They can constitute the raw materials for preparing synthetic graphite, which can be used in some types of batteries and fuel cells, and in carbon electrodes for electrochemical capacitors. The performances in terms of capacitance, electrical conductivity, potential, charge and discharge rates, power density, etc. have been reported to be very close to those of commercial devices. The recent progress in the activation protocols brought to higher fuel gas storage capacities, especially in cryogenic conditions and under high pressure, and opened the possibility to apply these materials in new application fields. In catalysis, advances in the use of biomass-derived chars and active carbons have been made thanks to the improvement of the modification techniques. The optimization of the engineering methodologies allows to lower the cost of the activation processes of biomass-derived chars and to tune the char properties to adapt them to the final application. The present paper aims to give a comprehensive survey of already-well-established or future potential energy applications of biomass-derived chars. A critical comparison of their use in different processes is reported and their modification by various catalytic, physical and chemical routes is detailed.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Biomass-derived chars present energy density values close to those of fossil fuels and therefore they are good candidates in electricity or heat production plants with only minor drawbacks compared to fossil fuels. Even if co-firing seems the most attractive solution for near-term applications, processes based on combustion and gasification (which are competing in dependence of the need of heat or electricity) are receiving renewed attention. Thanks to their high carbon content, and their high specific surface area and developed porous structure, biomass-derived chars can be treated and converted into activated carbons and applied in many different field (as energy storage materials for gaseous fuels, mainly hydrogen and methane, or as electrodes). They can constitute the raw materials for preparing synthetic graphite, which can be used in some types of batteries and fuel cells, and in carbon electrodes for electrochemical capacitors. The performances in terms of capacitance, electrical conductivity, potential, charge and discharge rates, power density, etc. have been reported to be very close to those of commercial devices. The recent progress in the activation protocols brought to higher fuel gas storage capacities, especially in cryogenic conditions and under high pressure, and opened the possibility to apply these materials in new application fields. In catalysis, advances in the use of biomass-derived chars and active carbons have been made thanks to the improvement of the modification techniques. The optimization of the engineering methodologies allows to lower the cost of the activation processes of biomass-derived chars and to tune the char properties to adapt them to the final application. The present paper aims to give a comprehensive survey of already-well-established or future potential energy applications of biomass-derived chars. A critical comparison of their use in different processes is reported and their modification by various catalytic, physical and chemical routes is detailed. |
Massara, Natalia; Marjaoui, Adil; Stephan, Regis; Hanf, Marie-Christine; Derivaz, Mickael; Dentel, Didier; Hajjar-Garreau, Samar; Mehdaoui, Ahmed; Diani, Mustapha; Sonnet, Philippe; Pirri, Carmelo Experimental molecular adsorption: electronic buffer effect of germanene on Al(111) (Article de journal) 2d Materials, 6 (3), p. 035016, 2019. @article{Massara2019, title = {Experimental molecular adsorption: electronic buffer effect of germanene on Al(111)}, author = { Natalia Massara and Adil Marjaoui and Regis Stephan and Marie-Christine Hanf and Mickael Derivaz and Didier Dentel and Samar Hajjar-Garreau and Ahmed Mehdaoui and Mustapha Diani and Philippe Sonnet and Carmelo Pirri}, doi = {10.1088/2053-1583/ab1601}, year = {2019}, date = {2019-07-01}, journal = {2d Materials}, volume = {6}, number = {3}, pages = {035016}, abstract = {The interaction of organic C-60 molecules with germanene grown on Al(1 1 1) is investigated by experimental tools and calculations. By mean of scanning tunneling microscopy, we show that a single but disordered C-60 layer is formed upon deposition in the monolayer range. Density functional theory calculations indicate that van der Waals and electrostatic interactions are present between the C-60 layer and the germanene, without formation of covalent bond. Moreover, the C-60 molecules are adsorbed without major crystallographic and charge modifications at the interface between germanene and the Al(1 1 1) substrate. The predicted charge transfer from the Al(1 1 1) substrate to the C-60 molecules is very small, which means that the germanene layer acts as an electronic buffer between the highly electron attractor C-60 molecules and the large electron reservoir Al(1 1 1). This leaves the C-60 layer quite uncharged, and so preserves its electron attractor properties for further layers grown on it, in the design of new molecular sensors.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The interaction of organic C-60 molecules with germanene grown on Al(1 1 1) is investigated by experimental tools and calculations. By mean of scanning tunneling microscopy, we show that a single but disordered C-60 layer is formed upon deposition in the monolayer range. Density functional theory calculations indicate that van der Waals and electrostatic interactions are present between the C-60 layer and the germanene, without formation of covalent bond. Moreover, the C-60 molecules are adsorbed without major crystallographic and charge modifications at the interface between germanene and the Al(1 1 1) substrate. The predicted charge transfer from the Al(1 1 1) substrate to the C-60 molecules is very small, which means that the germanene layer acts as an electronic buffer between the highly electron attractor C-60 molecules and the large electron reservoir Al(1 1 1). This leaves the C-60 layer quite uncharged, and so preserves its electron attractor properties for further layers grown on it, in the design of new molecular sensors. |
Galiyeva, Perizat; Alem, Halima; Rinnert, Herve; Balan, Lavinia; Blanchard, Sebastien; Medjahdi, Ghouti; Uralbekov, Bolat; Schneider, Raphael Highly fluorescent, color tunable and magnetic quaternary Ag-In-Mn-Zn-S quantum dots (Article de journal) Inorganic Chemistry Frontiers, 6 (6), p. 1422–1431, 2019. @article{Galiyeva2019, title = {Highly fluorescent, color tunable and magnetic quaternary Ag-In-Mn-Zn-S quantum dots}, author = { Perizat Galiyeva and Halima Alem and Herve Rinnert and Lavinia Balan and Sebastien Blanchard and Ghouti Medjahdi and Bolat Uralbekov and Raphael Schneider}, doi = {10.1039/c9qi00131j}, year = {2019}, date = {2019-06-01}, journal = {Inorganic Chemistry Frontiers}, volume = {6}, number = {6}, pages = {1422--1431}, abstract = {Mn-Doped quantum dots (QDs) are of high interest for numerous applications like solar cells, optoelectronics, optosensing, or bioimaging. Here, we report the preparation of quaternary (AgInS2)(x)(MnS)(y)(ZnS)(1-x-y) QDs, thereafter noted Mn : AIZS via a thermally induced decomposition of Ag, In, Zn and Mn precursors in the presence of oleylamine and dodecanethiol. The Mn : AIZS QDs have an average diameter of 3.5 nm and their XRD patterns can be indexed with the orthorhombic phase of AgInS2. The incorporation of Mn2+ ions in the AIZS crystal lattice results in a red-shift of the photoluminescence (PL) emission maximum depending on the Mn2+ content. The PL quantum yields decrease upon loading with Mn2+ but remained high (53-31%) until 50% theoretical loading in Mn2+. Steady state, PL excitation and time-resolved PL measurements suggest that Mn2+-dependent trap states are involved in the PL emission. Mn : AIZS QDs exhibit also magnetic properties. In addition, Mn : AIZS QDs can easily be transferred to the aqueous phase using the PMAO amphiphilic polymer without alteration of their optical properties (PL quantum yield up to 51%), revealing their high potential for biological applications.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Mn-Doped quantum dots (QDs) are of high interest for numerous applications like solar cells, optoelectronics, optosensing, or bioimaging. Here, we report the preparation of quaternary (AgInS2)(x)(MnS)(y)(ZnS)(1-x-y) QDs, thereafter noted Mn : AIZS via a thermally induced decomposition of Ag, In, Zn and Mn precursors in the presence of oleylamine and dodecanethiol. The Mn : AIZS QDs have an average diameter of 3.5 nm and their XRD patterns can be indexed with the orthorhombic phase of AgInS2. The incorporation of Mn2+ ions in the AIZS crystal lattice results in a red-shift of the photoluminescence (PL) emission maximum depending on the Mn2+ content. The PL quantum yields decrease upon loading with Mn2+ but remained high (53-31%) until 50% theoretical loading in Mn2+. Steady state, PL excitation and time-resolved PL measurements suggest that Mn2+-dependent trap states are involved in the PL emission. Mn : AIZS QDs exhibit also magnetic properties. In addition, Mn : AIZS QDs can easily be transferred to the aqueous phase using the PMAO amphiphilic polymer without alteration of their optical properties (PL quantum yield up to 51%), revealing their high potential for biological applications. |
Zuo, X L; Song, H S; Shao, H J; Wei, T; Guo, J B Aging of OMMT/halogen-antimony-filled LGFPA6 composite: Effect on static and dynamic mechanical properties and fire behaviors (Article de journal) Polymer Composites, 40 (6), p. 2208–2218, 2019. @article{Zuo2019, title = {Aging of OMMT/halogen-antimony-filled LGFPA6 composite: Effect on static and dynamic mechanical properties and fire behaviors}, author = { X. L. Zuo and H. S. Song and H. J. Shao and T. Wei and J. B. Guo}, doi = {10.1002/pc.25026}, year = {2019}, date = {2019-06-01}, journal = {Polymer Composites}, volume = {40}, number = {6}, pages = {2208--2218}, abstract = {The static and dynamic mechanical properties and fire behaviors for long-glass-fiber reinforced polyamide 6 composite filled with organo-modified montmorillonite/brominated epoxy resins/antimony trioxide (OMMT/FR/LGFPA6) have been investigated by comparison with the formulation without OMMT (FR/LGFPA6), being dealt with accelerated aging condition. Relative to the unaged composites, both aged composites presented the improved static mechanical properties after 10-day aging, the increased degree of cross-linking in the amorphous region, and the increased LOI value as well as maintained the optimal UL-94 rating. However, after a long-time aging exposure, the aged FR/LGFPA6 composite was more flammable and its mechanical properties were more severely impacted by aging. Remarkably, substitution of a certain content of halogen-antimony flame retardants with OMMT not only slowed down the rate of degradation but also weakened the flammability for FR/LGFPA6 composite over the whole period of aging. POLYM. COMPOS., 40:2208-2218, 2019. (c) 2018 Society of Plastics Engineers}, keywords = {}, pubstate = {published}, tppubtype = {article} } The static and dynamic mechanical properties and fire behaviors for long-glass-fiber reinforced polyamide 6 composite filled with organo-modified montmorillonite/brominated epoxy resins/antimony trioxide (OMMT/FR/LGFPA6) have been investigated by comparison with the formulation without OMMT (FR/LGFPA6), being dealt with accelerated aging condition. Relative to the unaged composites, both aged composites presented the improved static mechanical properties after 10-day aging, the increased degree of cross-linking in the amorphous region, and the increased LOI value as well as maintained the optimal UL-94 rating. However, after a long-time aging exposure, the aged FR/LGFPA6 composite was more flammable and its mechanical properties were more severely impacted by aging. Remarkably, substitution of a certain content of halogen-antimony flame retardants with OMMT not only slowed down the rate of degradation but also weakened the flammability for FR/LGFPA6 composite over the whole period of aging. POLYM. COMPOS., 40:2208-2218, 2019. (c) 2018 Society of Plastics Engineers |
Ferjani, Ibn A; Jeguirim, M; Jellali, S; Limousy, L; Courson, C; Akrout, H; Thevenin, N; Ruidavets, L; Muller, A; Bennici, S The use of exhausted grape marc to produce biofuels and biofertilizers: Effect of pyrolysis temperatures on biochars properties (Article de journal) Renewable & Sustainable Energy Reviews, 107 , p. 425–433, 2019. @article{IbnFerjani2019, title = {The use of exhausted grape marc to produce biofuels and biofertilizers: Effect of pyrolysis temperatures on biochars properties}, author = { A. Ibn Ferjani and M. Jeguirim and S. Jellali and L. Limousy and C. Courson and H. Akrout and N. Thevenin and L. Ruidavets and A. Muller and S. Bennici}, doi = {10.1016/j.rser.2019.03.034}, year = {2019}, date = {2019-06-01}, journal = {Renewable & Sustainable Energy Reviews}, volume = {107}, pages = {425--433}, abstract = {The wine industry represents an important economic sector in the Mediterranean countries. Currently, grape marc is valorized for ethanol production by distillation process generating a second residue called exhausted grape marc (EGM) that should be properly managed in order to avoid any related negative impacts onto the environment. In the present investigation, an innovative strategy was proposed to convert EGM into biofuels and biofertilizers through thermochemical conversion process such as carbonization/pyrolysis technique. In order to select the appropriate operating parameters, the impact of the slow pyrolysis temperatures of EGM (from 300 to 700 degrees C) on biochar production yields as well as their physico-chemical characteristics were assessed. The experimental results showed that the biochars yields production decrease with increasing the pyrolysis temperature and reach a plateau above 500 degrees C. The biochar yield at 500 degrees C is around 33%, which is amongst the highest values obtained for food processing residues. The biochar physico-chemical characterization showed a higher surface area (253.4 m(2)/g) was obtained for the char prepared at 600 degrees C. However, the maximum nutrients contents, namely potassium, nitrogen and phosphorus were registered at 500 degrees C. Based on the biochar yields and characteristics, it seems that EGM biochar produced through slow pyrolysis at 500 degrees C could be considered as a promising biofertilizer for agricultural purposes.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The wine industry represents an important economic sector in the Mediterranean countries. Currently, grape marc is valorized for ethanol production by distillation process generating a second residue called exhausted grape marc (EGM) that should be properly managed in order to avoid any related negative impacts onto the environment. In the present investigation, an innovative strategy was proposed to convert EGM into biofuels and biofertilizers through thermochemical conversion process such as carbonization/pyrolysis technique. In order to select the appropriate operating parameters, the impact of the slow pyrolysis temperatures of EGM (from 300 to 700 degrees C) on biochar production yields as well as their physico-chemical characteristics were assessed. The experimental results showed that the biochars yields production decrease with increasing the pyrolysis temperature and reach a plateau above 500 degrees C. The biochar yield at 500 degrees C is around 33%, which is amongst the highest values obtained for food processing residues. The biochar physico-chemical characterization showed a higher surface area (253.4 m(2)/g) was obtained for the char prepared at 600 degrees C. However, the maximum nutrients contents, namely potassium, nitrogen and phosphorus were registered at 500 degrees C. Based on the biochar yields and characteristics, it seems that EGM biochar produced through slow pyrolysis at 500 degrees C could be considered as a promising biofertilizer for agricultural purposes. |
Zhou, Ruchun; Malval, Jean-Pierre; Jin, Ming; Spangenberg, Arnaud; Pan, Haiyan; Wan, Decheng; Morlet-Savary, Fabrice; Knopf, Stephan A two-photon active chevron-shaped type I photoinitiator designed for 3D stereolithography (Article de journal) Chemical Communications, 55 (44), p. 6233–6236, 2019. @article{Zhou2019, title = {A two-photon active chevron-shaped type I photoinitiator designed for 3D stereolithography}, author = { Ruchun Zhou and Jean-Pierre Malval and Ming Jin and Arnaud Spangenberg and Haiyan Pan and Decheng Wan and Fabrice Morlet-Savary and Stephan Knopf}, doi = {10.1039/c9cc02923k}, year = {2019}, date = {2019-06-01}, journal = {Chemical Communications}, volume = {55}, number = {44}, pages = {6233--6236}, abstract = {We present herein the properties of a highly reactive type I photoinitiator with significant 2PA cross-sections (delta(720nm) similar to 90 GM). We demonstrate that this new type of photocleavable system exhibits very efficient two-photon polymerization abilities with performances amplified by more than two orders of magnitude with regards to those of a commercially available type I photoinitiator (Lucirin TPO-L) which is extensively employed for multiphoton 3D stereolithography.}, keywords = {}, pubstate = {published}, tppubtype = {article} } We present herein the properties of a highly reactive type I photoinitiator with significant 2PA cross-sections (delta(720nm) similar to 90 GM). We demonstrate that this new type of photocleavable system exhibits very efficient two-photon polymerization abilities with performances amplified by more than two orders of magnitude with regards to those of a commercially available type I photoinitiator (Lucirin TPO-L) which is extensively employed for multiphoton 3D stereolithography. |
Anfar, Z; Zbair, M; Ahsaine, H A; Abdellaoui, Y; Fakir, El A A; Amaterz, E; Jada, A; Alem, El N Preparation and Characterization of Porous Carbon@ZnO-NPs for Organic Compounds Removal: Classical Adsorption Versus Ultrasound Assisted Adsorption (Article de journal) Chemistryselect, 4 (17), p. 4981–4994, 2019. @article{Anfar2019, title = {Preparation and Characterization of Porous Carbon@ZnO-NPs for Organic Compounds Removal: Classical Adsorption Versus Ultrasound Assisted Adsorption}, author = { Z. Anfar and M. Zbair and H. A. Ahsaine and Y. Abdellaoui and A. A. El Fakir and E. Amaterz and A. Jada and N. El Alem}, doi = {10.1002/slct.201901043}, year = {2019}, date = {2019-05-01}, journal = {Chemistryselect}, volume = {4}, number = {17}, pages = {4981--4994}, abstract = {In this paper, the synthesis and characterization of porous carbon (PC) and porous carbon loaded ZnO nanoparticles (PC@ZnO) were investigated. The removal efficiency of Methylene Blue (MB) under ultrasound waves (UAA) and without ultrasound waves (SA) was studied considering the adsorbents dose, contact time, solution pH, temperature and initial dye concentration. Ultrasound irradiation have a positive effect on the removal efficiency of MB whereas ZnO nanoparticles incorporate in the surface of PC improve the regeneration efficiency of PC. PC@ZnO NPs shows high performance of MB removal using UAA, which was used for simultaneous removal of Crystal Violet (CV) and Congo Red (CR). The ultrasonic adsorption of CV/CR on PC@ZnO was found to be dependent on different parameters such as contact time, solution pH and initial dye concentration. The experimental results were found to follow the pseudo-second-order and Langmuir models. The adsorbed amount was found to be 64mg g(-1) (for CR) and 109mg g(-1) (for CV). Further, the effects of various parameters such as contact time, pH, initial dye concentration, and CV:CR ratio, were studied using central composite design coupled with response surface methodology. The data showed that the PC@ZnO has strong selective adsorption of CV dye in comparison to CR, and optimum conditions were found to be natural pH, 11.19mg, (55:45%) of CV:CR ratio, 25min and 30mg L-1 at adsorption temperature T=25 degrees C +/- 1. In these conditions, both dyes (CV and CR) are easily regenerated using HCl (0.1M).}, keywords = {}, pubstate = {published}, tppubtype = {article} } In this paper, the synthesis and characterization of porous carbon (PC) and porous carbon loaded ZnO nanoparticles (PC@ZnO) were investigated. The removal efficiency of Methylene Blue (MB) under ultrasound waves (UAA) and without ultrasound waves (SA) was studied considering the adsorbents dose, contact time, solution pH, temperature and initial dye concentration. Ultrasound irradiation have a positive effect on the removal efficiency of MB whereas ZnO nanoparticles incorporate in the surface of PC improve the regeneration efficiency of PC. PC@ZnO NPs shows high performance of MB removal using UAA, which was used for simultaneous removal of Crystal Violet (CV) and Congo Red (CR). The ultrasonic adsorption of CV/CR on PC@ZnO was found to be dependent on different parameters such as contact time, solution pH and initial dye concentration. The experimental results were found to follow the pseudo-second-order and Langmuir models. The adsorbed amount was found to be 64mg g(-1) (for CR) and 109mg g(-1) (for CV). Further, the effects of various parameters such as contact time, pH, initial dye concentration, and CV:CR ratio, were studied using central composite design coupled with response surface methodology. The data showed that the PC@ZnO has strong selective adsorption of CV dye in comparison to CR, and optimum conditions were found to be natural pH, 11.19mg, (55:45%) of CV:CR ratio, 25min and 30mg L-1 at adsorption temperature T=25 degrees C +/- 1. In these conditions, both dyes (CV and CR) are easily regenerated using HCl (0.1M). |
Pichot, V; Guerchoux, M; Muller, O; Guillevic, M; Fioux, P; Merlat, L; Spitzer, D Nanodiamond coating by polyethylenimine for optical limitation (Article de journal) Diamond and Related Materials, 95 , p. 55–59, 2019. @article{Pichot2019, title = {Nanodiamond coating by polyethylenimine for optical limitation}, author = { V. Pichot and M. Guerchoux and O. Muller and M. Guillevic and P. Fioux and L. Merlat and D. Spitzer}, doi = {10.1016/j.diamond.2019.04.001}, year = {2019}, date = {2019-05-01}, journal = {Diamond and Related Materials}, volume = {95}, pages = {55--59}, abstract = {Polyethylenimine (PEI) is used to elaborate detonation nanodiamonds coated with a polymer material. Evolution of the nanodiamonds surface charge depending on the PEI concentration is revealed by a zeta potential study. While the surface charge of the nanodiamond is negative due to its oxygenated functional groups, the cationic polymer allows reversing it to a positive one. Spectroscopy characterizations are used to investigate the PEI interaction with the nanodiamonds and to estimate the very small thickness of the PEI layer on the nanodiamonds surface. The oxygenated functional groups of the nanoparticles interact electrostatically with the PEI amine groups. The good performances of the non-linear optical properties of this material are demonstrated at a wavelength of 1064 nm.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Polyethylenimine (PEI) is used to elaborate detonation nanodiamonds coated with a polymer material. Evolution of the nanodiamonds surface charge depending on the PEI concentration is revealed by a zeta potential study. While the surface charge of the nanodiamond is negative due to its oxygenated functional groups, the cationic polymer allows reversing it to a positive one. Spectroscopy characterizations are used to investigate the PEI interaction with the nanodiamonds and to estimate the very small thickness of the PEI layer on the nanodiamonds surface. The oxygenated functional groups of the nanoparticles interact electrostatically with the PEI amine groups. The good performances of the non-linear optical properties of this material are demonstrated at a wavelength of 1064 nm. |
Clair, Charles; Lallam, Abdelaziz; Rosenthal, Martin; Sztucki, Michael; Vatankhah-Varnosfaderani, Mohammad; Keith, Andrew N; Cong, Yidan; Liang, Heyi; Dobrynin, Andrey V; Sheiko, Sergei S; Ivanov, Dimitri A Strained Bottlebrushes in Super-Soft Physical Networks (Article de journal) Acs Macro Letters, 8 (5), p. 530–534, 2019. @article{Clair2019, title = {Strained Bottlebrushes in Super-Soft Physical Networks}, author = { Charles Clair and Abdelaziz Lallam and Martin Rosenthal and Michael Sztucki and Mohammad Vatankhah-Varnosfaderani and Andrew N. Keith and Yidan Cong and Heyi Liang and Andrey V. Dobrynin and Sergei S. Sheiko and Dimitri A. Ivanov}, doi = {10.1021/acsmacrolett.9b00106}, year = {2019}, date = {2019-05-01}, journal = {Acs Macro Letters}, volume = {8}, number = {5}, pages = {530--534}, abstract = {ABA triblock copolymers composed of a poly(dimethylsiloxane) (PDMS) bottlebrush central block and linear poly(methyl methacrylate) (PMMA) terminal blocks self assemble into a physical network of PDMS bottlebrush strands connected by PMMA spherical domains. A combination of small- and ultrasmall-angle X-ray scattering techniques was used to concurrently examine dimensions of PMMA spherical domains and PDMS bottlebrush strands both in the bulk and at the PMMA PDMS interface. In agreement with scaling model predictions, the degrees of polymerization of the bottlebrush backbone (n(bb)) and PMMA block (n(A)) correlate with the measured PMMA domain size and area per molecule at the PMMA-PDMS interface as D-A proportional to (n(bb)n(A))(1/3) and S proportional to n(A)(2/3)n(bb)(-1/3), respectively. In the bulk, bottlebrush strands are extended due to steric repulsion between the side chains and unfavorable interactions between the different blocks. At the PMMA-PDMS interface with large curvature, packing constraints require additional bottlebrush backbone extension and alignment of side chains along the backbone in the direction perpendicular to the interface.}, keywords = {}, pubstate = {published}, tppubtype = {article} } ABA triblock copolymers composed of a poly(dimethylsiloxane) (PDMS) bottlebrush central block and linear poly(methyl methacrylate) (PMMA) terminal blocks self assemble into a physical network of PDMS bottlebrush strands connected by PMMA spherical domains. A combination of small- and ultrasmall-angle X-ray scattering techniques was used to concurrently examine dimensions of PMMA spherical domains and PDMS bottlebrush strands both in the bulk and at the PMMA PDMS interface. In agreement with scaling model predictions, the degrees of polymerization of the bottlebrush backbone (n(bb)) and PMMA block (n(A)) correlate with the measured PMMA domain size and area per molecule at the PMMA-PDMS interface as D-A proportional to (n(bb)n(A))(1/3) and S proportional to n(A)(2/3)n(bb)(-1/3), respectively. In the bulk, bottlebrush strands are extended due to steric repulsion between the side chains and unfavorable interactions between the different blocks. At the PMMA-PDMS interface with large curvature, packing constraints require additional bottlebrush backbone extension and alignment of side chains along the backbone in the direction perpendicular to the interface. |
Khadem-Abbassi, Kiana; Rinnert, Herve; Balan, Lavinia; Doumandji, Zahra; Joubert, Olivier; Masteri-Farahani, Majid; Schneider, Raphael CdTe0.5S0.5/ZnS Quantum Dots Embedded in a Molecularly Imprinted Polymer for the Selective Optosensing of Dopamine. (Article de journal) Nanomaterials (Basel, Switzerland), 9 (5), 2019. @article{Khadem-Abbassi2019, title = {CdTe0.5S0.5/ZnS Quantum Dots Embedded in a Molecularly Imprinted Polymer for the Selective Optosensing of Dopamine.}, author = { Kiana Khadem-Abbassi and Herve Rinnert and Lavinia Balan and Zahra Doumandji and Olivier Joubert and Majid Masteri-Farahani and Raphael Schneider}, doi = {10.3390/nano9050693}, year = {2019}, date = {2019-05-01}, journal = {Nanomaterials (Basel, Switzerland)}, volume = {9}, number = {5}, abstract = {This work describes the preparation of molecularly imprinted polymer (MIP)-modified core/shell CdTe0.5S0.5/ZnS quantum dots (QDs). The QDs@MIP particles were used for the selective and sensitive detection of dopamine (DA). Acrylamide, which is able to form hydrogen bonds with DA, and ethylene glycol dimethylacrylate (EGDMA) as cross-linker were used for the preparation of the MIP. Highly cross-linked polymer particles with sizes up to 1 m containing the dots were obtained after the polymerization. After the removal of the DA template, MIP-modified QDs (QDs@MIP) exhibit a high photoluminescence (PL) with an intensity similar to that of QDs embedded in the nonimprinted polymer (NIP). A linear PL decrease was observed upon addition of DA to QDs@MIP and the PL response was in the linear ranges from 2.63 M to 26.30 M with a limit of detection of 6.6 nM. The PL intensity of QDs@MIP was quenched selectively by DA. The QDs@MIP particles developed in this work are easily prepared and of low cost and are therefore of high interest for the sensitive and selective detection of DA in biological samples.}, keywords = {}, pubstate = {published}, tppubtype = {article} } This work describes the preparation of molecularly imprinted polymer (MIP)-modified core/shell CdTe0.5S0.5/ZnS quantum dots (QDs). The QDs@MIP particles were used for the selective and sensitive detection of dopamine (DA). Acrylamide, which is able to form hydrogen bonds with DA, and ethylene glycol dimethylacrylate (EGDMA) as cross-linker were used for the preparation of the MIP. Highly cross-linked polymer particles with sizes up to 1 m containing the dots were obtained after the polymerization. After the removal of the DA template, MIP-modified QDs (QDs@MIP) exhibit a high photoluminescence (PL) with an intensity similar to that of QDs embedded in the nonimprinted polymer (NIP). A linear PL decrease was observed upon addition of DA to QDs@MIP and the PL response was in the linear ranges from 2.63 M to 26.30 M with a limit of detection of 6.6 nM. The PL intensity of QDs@MIP was quenched selectively by DA. The QDs@MIP particles developed in this work are easily prepared and of low cost and are therefore of high interest for the sensitive and selective detection of DA in biological samples. |
Dolgopolov, Andrey V; Grafskaia, Kseniia N; Bovsunovskaya, Polina V; Melnikova, Elina R; Ivanov, Dimitri A; Pich, Andrij; Zhu, Xiaomin; Moller, Martin Aqueous microgels modified with photosensitive wedge-shaped amphiphilic molecules: synthesis, structure and photochemical behaviour. (Article de journal) Photochemical & photobiological sciences : Official journal of the European Photochemistry Association and the European Society for Photobiology, 2019. @article{Dolgopolov2019, title = {Aqueous microgels modified with photosensitive wedge-shaped amphiphilic molecules: synthesis, structure and photochemical behaviour.}, author = { Andrey V. Dolgopolov and Kseniia N. Grafskaia and Polina V. Bovsunovskaya and Elina R. Melnikova and Dimitri A. Ivanov and Andrij Pich and Xiaomin Zhu and Martin Moller}, doi = {10.1039/c9pp00044e}, year = {2019}, date = {2019-05-01}, journal = {Photochemical & photobiological sciences : Official journal of the European Photochemistry Association and the European Society for Photobiology}, abstract = {Aqueous microgels based on poly(N-vinylcaprolactam) with reversible temperature-induced volume transition are promising "smart" materials for various applications. In this work, the microgels are modified via acid-base interaction by wedge-shaped amphiphilic sulfonic acid molecules with alkyl chains of different lengths and an azobenzene group. In contrast to the pristine microgel the modified microgels retain colloidal stability in water and show different responses to the change of temperature and pH. The azobenzene group in the ligand molecules acts as a spectroscopic and kinetic probe sensing the microenvironment inside the microgel particles. Thus, the observed hyperchromicity upon heating suggests the enhancement of hydrophobicity with the increase of temperature. The hydrophobicity of the microgel interior increases with the increase of the modification degree as indicated by the increase of activation energy of the thermal Z/E isomerization of the azobenzene group.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Aqueous microgels based on poly(N-vinylcaprolactam) with reversible temperature-induced volume transition are promising "smart" materials for various applications. In this work, the microgels are modified via acid-base interaction by wedge-shaped amphiphilic sulfonic acid molecules with alkyl chains of different lengths and an azobenzene group. In contrast to the pristine microgel the modified microgels retain colloidal stability in water and show different responses to the change of temperature and pH. The azobenzene group in the ligand molecules acts as a spectroscopic and kinetic probe sensing the microenvironment inside the microgel particles. Thus, the observed hyperchromicity upon heating suggests the enhancement of hydrophobicity with the increase of temperature. The hydrophobicity of the microgel interior increases with the increase of the modification degree as indicated by the increase of activation energy of the thermal Z/E isomerization of the azobenzene group. |
Baralle, Alexandre; Garra, Patxi; Graff, Bernadette; Morlet-Savary, Fabrice; Dietlin, Celine; Fouassier, Jean Pierre; Lakhdar, Sami; Lalevee, Jacques Iodinated Polystyrene for Polymeric Charge Transfer Complexes: Toward High-Performance Near-UV and Visible Light Macrophotoinitiators (Article de journal) Macromolecules, 52 (9), p. 3448–3453, 2019. @article{Baralle2019, title = {Iodinated Polystyrene for Polymeric Charge Transfer Complexes: Toward High-Performance Near-UV and Visible Light Macrophotoinitiators}, author = { Alexandre Baralle and Patxi Garra and Bernadette Graff and Fabrice Morlet-Savary and Celine Dietlin and Jean Pierre Fouassier and Sami Lakhdar and Jacques Lalevee}, doi = {10.1021/acs.macromol.9b00252}, year = {2019}, date = {2019-05-01}, journal = {Macromolecules}, volume = {52}, number = {9}, pages = {3448--3453}, abstract = {In recent works, charge transfer complexes (CTCs) have proved to be useful photoinitiating agents to trigger free radical polymerization. However, because of their low molecular weights, migration issues remain very important. In line with pressing migration concerns around photoinitiating systems (e.g., in 3D polymer networks), we report here the use of the first polymeric CTC based on iodinated polystyrene/amine interactions. This study shows the formation of the CTC between the polystyrene derivative (electron acceptor EA) and a tertiary alkylamine (electron donor ED); the ability of this EA/ED couple in a CTC to act as a photoinitiator for the polymerization of multifunctional acrylates upon LED@405 nm irradiation is investigated. Examples of applications to 3D-resolved laser write of thick controlled samples (1 mm) are provided.}, keywords = {}, pubstate = {published}, tppubtype = {article} } In recent works, charge transfer complexes (CTCs) have proved to be useful photoinitiating agents to trigger free radical polymerization. However, because of their low molecular weights, migration issues remain very important. In line with pressing migration concerns around photoinitiating systems (e.g., in 3D polymer networks), we report here the use of the first polymeric CTC based on iodinated polystyrene/amine interactions. This study shows the formation of the CTC between the polystyrene derivative (electron acceptor EA) and a tertiary alkylamine (electron donor ED); the ability of this EA/ED couple in a CTC to act as a photoinitiator for the polymerization of multifunctional acrylates upon LED@405 nm irradiation is investigated. Examples of applications to 3D-resolved laser write of thick controlled samples (1 mm) are provided. |
Wang, Dengxia; Garra, Patxi; Szillat, Florian; Fouassier, Jean Pierre; Lalevee, Jacques Silane Based Redox Initiating Systems: Toward a Safer Amine-Free, Peroxide-Free, and Metal-Free Approach (Article de journal) Macromolecules, 52 (9), p. 3351–3358, 2019. @article{Wang2019, title = {Silane Based Redox Initiating Systems: Toward a Safer Amine-Free, Peroxide-Free, and Metal-Free Approach}, author = { Dengxia Wang and Patxi Garra and Florian Szillat and Jean Pierre Fouassier and Jacques Lalevee}, doi = {10.1021/acs.macromol.9b00233}, year = {2019}, date = {2019-05-01}, journal = {Macromolecules}, volume = {52}, number = {9}, pages = {3351--3358}, abstract = {Room temperature redox initiated free radical polymerization (RFRP) has always attracted high attention in the field of materials due to its advantages of energy saving, high efficiency, and easy operation. However, the current redox initiating systems are based on toxic aromatic amines and hazardous peroxides (e.g., dibenzoylperoxide). In the present paper, the redox two component (2K) initiating performances of silanes (as reducing agents) in combination with a highly stable iodonium salt (as oxidizing agent) were studied for the first time under mild conditions (RT, under air). Optical pyrometry measurements and DSC investigation results showed that the diphenylsilane (DPS) exhibited a unique initiating property for several (meth)acrylate monomers. Remarkably, thermal postcuring (B-stage) is also possible using this system. Based on electron spin resonance (ESR) experiments, the initiating chemical mechanisms of RFRP are established. Importantly, the new proposed initiating systems can be used for the preparation of tack-free glass fibers and carbon fibers composites at room temperature.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Room temperature redox initiated free radical polymerization (RFRP) has always attracted high attention in the field of materials due to its advantages of energy saving, high efficiency, and easy operation. However, the current redox initiating systems are based on toxic aromatic amines and hazardous peroxides (e.g., dibenzoylperoxide). In the present paper, the redox two component (2K) initiating performances of silanes (as reducing agents) in combination with a highly stable iodonium salt (as oxidizing agent) were studied for the first time under mild conditions (RT, under air). Optical pyrometry measurements and DSC investigation results showed that the diphenylsilane (DPS) exhibited a unique initiating property for several (meth)acrylate monomers. Remarkably, thermal postcuring (B-stage) is also possible using this system. Based on electron spin resonance (ESR) experiments, the initiating chemical mechanisms of RFRP are established. Importantly, the new proposed initiating systems can be used for the preparation of tack-free glass fibers and carbon fibers composites at room temperature. |
Pinot, Matthieu; Lebeau, Benedicte; Nouali, Habiba; Daou, Jean T; Patarin, Joel; Ryzhikov, Andrey High pressure intrusion of water and LiCl aqueous solutions in hydrophobic KIT-6 mesoporous silica: Influence of the grafted group nature (Article de journal) Microporous and Mesoporous Materials, 280 , p. 248–255, 2019. @article{Pinot2019, title = {High pressure intrusion of water and LiCl aqueous solutions in hydrophobic KIT-6 mesoporous silica: Influence of the grafted group nature}, author = { Matthieu Pinot and Benedicte Lebeau and Habiba Nouali and T. Jean Daou and Joel Patarin and Andrey Ryzhikov}, doi = {10.1016/j.micromeso.2019.02.006}, year = {2019}, date = {2019-05-01}, journal = {Microporous and Mesoporous Materials}, volume = {280}, pages = {248--255}, abstract = {High pressure intrusion-extrusion of water and LiCl aqueous solutions in KIT-6 mesoporous silica grafted with alkyl or perfluoroalkyl groups have been studied for absorption of mechanical energy. The "grafted KIT-6 LiCl solution" systems demonstrate a shock absorber behavior with a large hysteresis between intrusion and extrusion curves and partially irreversible intrusion in the first intrusion-extrusion cycle. The samples of KIT-6 with perfluroalkyl grafting demonstrate higher values of intrusion pressure in comparison with ones grafted with alkyl groups, but lower intruded volume. It has been found that the intrusion of LiCl solutions leads to a considerable increase of intrusion pressure, particularly pronounced in the case of the samples grafted with perfluoroalkyl groups. This increase is higher than one expected from the Laplace-Washburn equation. When salt concentration increases, the intrusion becomes more reversible in the case of alkyl grafting, but slightly less in the case of perfluoroalkyl one.}, keywords = {}, pubstate = {published}, tppubtype = {article} } High pressure intrusion-extrusion of water and LiCl aqueous solutions in KIT-6 mesoporous silica grafted with alkyl or perfluoroalkyl groups have been studied for absorption of mechanical energy. The "grafted KIT-6 LiCl solution" systems demonstrate a shock absorber behavior with a large hysteresis between intrusion and extrusion curves and partially irreversible intrusion in the first intrusion-extrusion cycle. The samples of KIT-6 with perfluroalkyl grafting demonstrate higher values of intrusion pressure in comparison with ones grafted with alkyl groups, but lower intruded volume. It has been found that the intrusion of LiCl solutions leads to a considerable increase of intrusion pressure, particularly pronounced in the case of the samples grafted with perfluoroalkyl groups. This increase is higher than one expected from the Laplace-Washburn equation. When salt concentration increases, the intrusion becomes more reversible in the case of alkyl grafting, but slightly less in the case of perfluoroalkyl one. |
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IS2M
Bâtiment CNRS
15, rue Jean Starcky - BP 2488
68057 Mulhouse cedex
Bâtiment IRJBD
3 bis, rue Alfred Werner
68093 Mulhouse cedex
tel: (+33)3 89 60 87 00
fax: (+33)3 89 60 87 99
Réseaux sociaux
IS2M
Bâtiment CNRS
15, rue Jean Starcky - BP 2488
68057 Mulhouse cedex
Bâtiment IRJBD
3 bis, rue Alfred Werner
68093 Mulhouse cedex
tel: (+33)3 89 60 87 00
fax: (+33)3 89 60 87 99
Réseaux sociaux
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