Nos publications
2018 |
Jouane, A; Moubah, R; Schmerber, G; Larde, R; Odarchenko, Y; Ivanov, D A; Lassri, H; Chapuis, Y - A; Jouane, Y Morphological and micro-structural interface characterization in multilayer inverted polymer-fullerene bulk heterojunction solar cells (Article de journal) Solar Energy Materials and Solar Cells, 180 , p. 258–265, 2018. @article{Jouane2018, title = {Morphological and micro-structural interface characterization in multilayer inverted polymer-fullerene bulk heterojunction solar cells}, author = { A. Jouane and R. Moubah and G. Schmerber and R. Larde and Y. Odarchenko and D. A. Ivanov and H. Lassri and Y. -. A. Chapuis and Y. Jouane}, doi = {10.1016/j.solmat.2017.06.044}, year = {2018}, date = {2018-06-01}, journal = {Solar Energy Materials and Solar Cells}, volume = {180}, pages = {258--265}, abstract = {Inverted polymer solar cells based on P3HT/PCBM bulk heterojunction were prepared on flexible polyethylene naphthalate (PEN) substrate. The effect of annealing of the PEN/ITO/ZnO multilayer and ZnO/P3HT:PCBM on the structural, morphological, photophysical and photovoltaic properties was investigated and scrutinized directly on the OPV devices using atom probe tomography (APT), scanning electron microscopy (SEM) and microfocus X-ray techniques. We carried out a 3D reconstruction of the interfaces of the multilayer containing PEN/ITO, ZnO/ITO and P3HT:PCBM/ZnO to address the interface micro-structure and its influence on the morphology of the photoactive film. The analyses show that the morphology of the interfaces is affected by the structure of each layer of the BHJ devices causing orientation of P3HT crystals with PCBM aggregates and ZnO, which in turn leads to a significant change of the charge transport across each layer and therefore photovoltaic performances.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Inverted polymer solar cells based on P3HT/PCBM bulk heterojunction were prepared on flexible polyethylene naphthalate (PEN) substrate. The effect of annealing of the PEN/ITO/ZnO multilayer and ZnO/P3HT:PCBM on the structural, morphological, photophysical and photovoltaic properties was investigated and scrutinized directly on the OPV devices using atom probe tomography (APT), scanning electron microscopy (SEM) and microfocus X-ray techniques. We carried out a 3D reconstruction of the interfaces of the multilayer containing PEN/ITO, ZnO/ITO and P3HT:PCBM/ZnO to address the interface micro-structure and its influence on the morphology of the photoactive film. The analyses show that the morphology of the interfaces is affected by the structure of each layer of the BHJ devices causing orientation of P3HT crystals with PCBM aggregates and ZnO, which in turn leads to a significant change of the charge transport across each layer and therefore photovoltaic performances. |
Ouachtak, Hassan; Akhouairi, Siham; Addi, Abdelaziz Ait; Akbour, Rachid Ait; Jada, Amane; Douch, Jamaa; Hamdani, Mohamed Mobility and retention of phenolic acids through a goethite-coated quartz sand column (Article de journal) Colloids and Surfaces A-physicochemical and Engineering Aspects, 546 , p. 9–19, 2018. @article{Ouachtak2018, title = {Mobility and retention of phenolic acids through a goethite-coated quartz sand column}, author = { Hassan Ouachtak and Siham Akhouairi and Abdelaziz Ait Addi and Rachid Ait Akbour and Amane Jada and Jamaa Douch and Mohamed Hamdani}, doi = {10.1016/j.colsurfa.2018.02.071}, year = {2018}, date = {2018-06-01}, journal = {Colloids and Surfaces A-physicochemical and Engineering Aspects}, volume = {546}, pages = {9--19}, abstract = {In the present work, a natural mineral, such as quartz sand (NQS), was modified with a small amount of goethite to yield a goethite-coated quartz sand (GCQS) adsorbent that was used for depolluting water contaminated with a series of phenolic acids that have various numbers and positions of hydroxyl groups in the benzene ring. Thus, the transport and retention of gallic acid and its derivatives from water onto GCQS column were carried out at ambient temperature. Prior to the column adsorption experiments, the GCQS adsorbent was characterized with various methods such as X-ray diffraction, X-ray fluorescence, and scanning electron microscopy (SEM) coupled with X-ray microanalysis and zeta potential. The amount of adsorbed phenolic acid at the GCQS-water interface was found to be controlled by hydrogen bonding and electrostatic interactions, and it was tuned by varying parameters such as the aqueous phase pH, the ionic strength and the nature of inorganic ions. In addition, the effect of the number and the positions of hydroxyl groups (-OH) on the benzoic acid mobility was also examined. The data indicate that adding no more than 2.5 wt% of goethite to NQS shifts the solid Isoelectrical Point from 2.5 for pure NQS to 5.7 for GCQS and leads to a 16-fold increase in the maximum adsorbed amount of gallic acid. Moreover, the adsorbed amount of gallic acid was also found to decrease in the presence of inorganic anions in the order Cl- > NO3- > SO42- > H2PO4-, and to decrease as the ionic strength of the aqueous phase increases. This study brings new insight to the role of colloid and interface science for mineral processing and the environment.}, keywords = {}, pubstate = {published}, tppubtype = {article} } In the present work, a natural mineral, such as quartz sand (NQS), was modified with a small amount of goethite to yield a goethite-coated quartz sand (GCQS) adsorbent that was used for depolluting water contaminated with a series of phenolic acids that have various numbers and positions of hydroxyl groups in the benzene ring. Thus, the transport and retention of gallic acid and its derivatives from water onto GCQS column were carried out at ambient temperature. Prior to the column adsorption experiments, the GCQS adsorbent was characterized with various methods such as X-ray diffraction, X-ray fluorescence, and scanning electron microscopy (SEM) coupled with X-ray microanalysis and zeta potential. The amount of adsorbed phenolic acid at the GCQS-water interface was found to be controlled by hydrogen bonding and electrostatic interactions, and it was tuned by varying parameters such as the aqueous phase pH, the ionic strength and the nature of inorganic ions. In addition, the effect of the number and the positions of hydroxyl groups (-OH) on the benzoic acid mobility was also examined. The data indicate that adding no more than 2.5 wt% of goethite to NQS shifts the solid Isoelectrical Point from 2.5 for pure NQS to 5.7 for GCQS and leads to a 16-fold increase in the maximum adsorbed amount of gallic acid. Moreover, the adsorbed amount of gallic acid was also found to decrease in the presence of inorganic anions in the order Cl- > NO3- > SO42- > H2PO4-, and to decrease as the ionic strength of the aqueous phase increases. This study brings new insight to the role of colloid and interface science for mineral processing and the environment. |
Banet, Philippe; Simonnet-Jegat, Corine; Goubard, Fabrice; Peralta, Sebastien; Lalevee, Jacques; Gigmes, Didier; Dumur, Frederic Electrochromic behavior of drop-casted thin films combining a semi-conducting polymer mixed with a Keggin-type polyoxometalate (Article de journal) Materials Chemistry and Physics, 211 , p. 312–320, 2018. @article{Banet2018, title = {Electrochromic behavior of drop-casted thin films combining a semi-conducting polymer mixed with a Keggin-type polyoxometalate}, author = { Philippe Banet and Corine Simonnet-Jegat and Fabrice Goubard and Sebastien Peralta and Jacques Lalevee and Didier Gigmes and Frederic Dumur}, doi = {10.1016/j.matchemphys.2018.02.046}, year = {2018}, date = {2018-06-01}, journal = {Materials Chemistry and Physics}, volume = {211}, pages = {312--320}, abstract = {A drop-casted thin film consisting of a Keggin-type polyoxometalate cluster K3PMo12O40 mixed with the semi-conducting poly(N-vinylcarbazole) (PVK) was deposited on top of ITO substrates. The resulting hybrid organic/inorganic film was characterized by electrochemistry, FT-IR spectroscopy, microscopies and spectroelectrochemistry. Interestingly, an electrochromic behavior could be evidenced from the resulting composite. (C) 2018 Elsevier B.V. All rights reserved.}, keywords = {}, pubstate = {published}, tppubtype = {article} } A drop-casted thin film consisting of a Keggin-type polyoxometalate cluster K3PMo12O40 mixed with the semi-conducting poly(N-vinylcarbazole) (PVK) was deposited on top of ITO substrates. The resulting hybrid organic/inorganic film was characterized by electrochemistry, FT-IR spectroscopy, microscopies and spectroelectrochemistry. Interestingly, an electrochromic behavior could be evidenced from the resulting composite. (C) 2018 Elsevier B.V. All rights reserved. |
Bodart, Philippe R; Delmotte, L; Rigolet, S; Brendle, J; Gougeon, Regis D Li-7F-19 TEDOR NMR to observe the lithium migration in heated montmorillonite (Article de journal) Applied Clay Science, 157 , p. 204–211, 2018. @article{Bodart2018, title = {Li-7F-19 TEDOR NMR to observe the lithium migration in heated montmorillonite}, author = { Philippe R. Bodart and L. Delmotte and S. Rigolet and J. Brendle and Regis D. Gougeon}, doi = {10.1016/j.clay.2018.03.007}, year = {2018}, date = {2018-06-01}, journal = {Applied Clay Science}, volume = {157}, pages = {204--211}, abstract = {The distribution of lithium ions in heated synthetic montmorillonites was studied by using F-19, Li-7 MAS and Li-7F-19 TEDOR nuclear magnetic resonance technics. To get the best of NMR spectroscopy, Na-montmorillonites, free of paramagnetic centres (Fe2+, Fe3+), were synthesized in fluoride medium, in order to have substitution of some hydroxyl groups by fluorine in the octahedral layer (Na-0.35[(Al1.69Mg0.36)vi(Si3.86Al0.14)(IV)O-10(OH0.95F0.05)(2)]). After Li+ exchange, mild heat treatments (from 110 to 250 degrees C during 24 h) were applied to follow the lithium migration. Both F-19 and Li-7 MAS spectra indicate that the lithium migration operates in two steps: at 110 degrees C, 86% of the lithium ions have moved to the hexagonal site. The remaining interlayer ions move progressively to this site when the heating temperature is in the range (170-250 degrees C]. For the first time a direct fluorine-lithium distance of 2.23 angstrom was measured by Li-7F-19 TEDOR, which uses fluorine as a highly selective and NMR-sensitive witness of atomic-scale motions inside porous media, and which agrees with the preferred hexagonal site for Li+ migration.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The distribution of lithium ions in heated synthetic montmorillonites was studied by using F-19, Li-7 MAS and Li-7F-19 TEDOR nuclear magnetic resonance technics. To get the best of NMR spectroscopy, Na-montmorillonites, free of paramagnetic centres (Fe2+, Fe3+), were synthesized in fluoride medium, in order to have substitution of some hydroxyl groups by fluorine in the octahedral layer (Na-0.35[(Al1.69Mg0.36)vi(Si3.86Al0.14)(IV)O-10(OH0.95F0.05)(2)]). After Li+ exchange, mild heat treatments (from 110 to 250 degrees C during 24 h) were applied to follow the lithium migration. Both F-19 and Li-7 MAS spectra indicate that the lithium migration operates in two steps: at 110 degrees C, 86% of the lithium ions have moved to the hexagonal site. The remaining interlayer ions move progressively to this site when the heating temperature is in the range (170-250 degrees C]. For the first time a direct fluorine-lithium distance of 2.23 angstrom was measured by Li-7F-19 TEDOR, which uses fluorine as a highly selective and NMR-sensitive witness of atomic-scale motions inside porous media, and which agrees with the preferred hexagonal site for Li+ migration. |
Aicha, Bechikh; Mohamed, Sassi; Jocelyne, Miehe-Brendle; Benedicte, Lebeau; Jean-Luc, Blin; Abdelkader, Bengueddach Preparation of new microporous titanium pillared kenyaite materials active for the photodegradation of methyl orange (Article de journal) Journal of Porous Materials, 25 (3), p. 801–812, 2018. @article{Aicha2018, title = {Preparation of new microporous titanium pillared kenyaite materials active for the photodegradation of methyl orange}, author = { Bechikh Aicha and Sassi Mohamed and Miehe-Brendle Jocelyne and Lebeau Benedicte and Blin Jean-Luc and Bengueddach Abdelkader}, doi = {10.1007/s10934-017-0493-z}, year = {2018}, date = {2018-06-01}, journal = {Journal of Porous Materials}, volume = {25}, number = {3}, pages = {801--812}, abstract = {In recent years, layered silicates have extensively been used to design new nanomaterials through functionalization. In this work, the lamellar sodium silicates magadiite and kenyaite have been hydrothermally synthesized in presence of ethanol as organic co-solvent. Materials of high purity and high crystallinity were obtained after only 24 h of crystallization at a temperature of 180 A degrees C for kenyaite and a temperature of 150 A degrees C for magadiite. It appears that the presence of ethanol in the synthesis medium tends not only to increase the crystallization rate, but also to stabilize the formation of magadiite.The as-synthesized Na-kenyaite was used as precursor for the preparation of titanium pillared clay materials. The resulting microporous titanium oxide pillared kenyaite materials exhibit large specific surface areas up to 180 m(2) g(-1) with a Ti contents up to 24 wt% and are active for the photocatalytic degradation under UV light irradiation of the organic dye methyl orange in water.}, keywords = {}, pubstate = {published}, tppubtype = {article} } In recent years, layered silicates have extensively been used to design new nanomaterials through functionalization. In this work, the lamellar sodium silicates magadiite and kenyaite have been hydrothermally synthesized in presence of ethanol as organic co-solvent. Materials of high purity and high crystallinity were obtained after only 24 h of crystallization at a temperature of 180 A degrees C for kenyaite and a temperature of 150 A degrees C for magadiite. It appears that the presence of ethanol in the synthesis medium tends not only to increase the crystallization rate, but also to stabilize the formation of magadiite.The as-synthesized Na-kenyaite was used as precursor for the preparation of titanium pillared clay materials. The resulting microporous titanium oxide pillared kenyaite materials exhibit large specific surface areas up to 180 m(2) g(-1) with a Ti contents up to 24 wt% and are active for the photocatalytic degradation under UV light irradiation of the organic dye methyl orange in water. |
Ryzhikov, Andrey; Daou, Jean T; Noualia, Habiba; Patarin, Joel; Ouwehand, Judith; Clerick, Sander; Canck, Els De; Voort, Pascal Van Der; Martens, Johan A Periodic mesoporous organosilicas as porous matrix for heterogeneous lyophobic systems (Article de journal) Microporous and Mesoporous Materials, 260 , p. 166–171, 2018. @article{Ryzhikov2018b, title = {Periodic mesoporous organosilicas as porous matrix for heterogeneous lyophobic systems}, author = {Andrey Ryzhikov and Jean T Daou and Habiba Noualia and Joel Patarin and Judith Ouwehand and Sander Clerick and Els De Canck and Pascal Van Der Voort and Johan A Martens}, doi = {10.1016/j.micromeso.2017.10.037}, year = {2018}, date = {2018-04-01}, journal = {Microporous and Mesoporous Materials}, volume = {260}, pages = {166--171}, abstract = {Periodic mesoporous organosilicas (PMO) have been studied for the first time as a porous matrix for heterogeneous lyophobic systems (HLS) for absorption and storage of mechanical energy by high pressure intrusion extrusion of electrolyte solutions. It has been shown that the intrusion of LiCl aqueous solutions in ethane bridged PMO material is irreversible that corresponds to a bumper behavior. The intrusion pressure increases strongly with the salt concentration - from 13 MPa for 5 M LiCl aqueous solution to 37 MPa for 20 M one. Such a pressure rise of 2.8 times is the highest observed for HIS based on mesoporous materials. Due to high intruded volume (0.63-0.72 mL/g) specific absorbed energy achieves 27 J/g, which is close to the best values ever obtained for HLS based on zeosils and mesoporous silica. The characterization shows that after the intrusion extrusion experiments the ordered pore arrangement largely stays intact, but a slight increase of the mesopore volume is observed.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Periodic mesoporous organosilicas (PMO) have been studied for the first time as a porous matrix for heterogeneous lyophobic systems (HLS) for absorption and storage of mechanical energy by high pressure intrusion extrusion of electrolyte solutions. It has been shown that the intrusion of LiCl aqueous solutions in ethane bridged PMO material is irreversible that corresponds to a bumper behavior. The intrusion pressure increases strongly with the salt concentration - from 13 MPa for 5 M LiCl aqueous solution to 37 MPa for 20 M one. Such a pressure rise of 2.8 times is the highest observed for HIS based on mesoporous materials. Due to high intruded volume (0.63-0.72 mL/g) specific absorbed energy achieves 27 J/g, which is close to the best values ever obtained for HLS based on zeosils and mesoporous silica. The characterization shows that after the intrusion extrusion experiments the ordered pore arrangement largely stays intact, but a slight increase of the mesopore volume is observed. |
Benaioun, N E; Maafa, I; Florentin, A; Denys, E; Hakiki, N E; Moulayat, N; Bubendorff, J L Applied Surface Science, 436 , p. 646–652, 2018. @article{Benaioun2018, title = {Time dependence of the natural passivation process on AISI 304 in an alkaline medium: Atomic force microscopy and scanning Kelvin probe force microscopy as additional tools to electrochemical impedance spectroscopy}, author = {N E Benaioun and I Maafa and A Florentin and E Denys and N E Hakiki and N Moulayat and J L Bubendorff}, doi = {10.1016/j.apsusc.2017.12.051}, year = {2018}, date = {2018-04-01}, journal = {Applied Surface Science}, volume = {436}, pages = {646--652}, abstract = {Thin surface films formed on AISI 304 samples in an alkaline solution of pH = 13 are studied by atomic force microscopy (AFM), scanning Kelvin probe force microscopy (SKPFM) and electrochemical impedance spectroscopy (EIS) as a function of immersion time. The results reveal that changes on EIS diagrams correspond to topographical modifications on the sample surface as shown by AFM. Both techniques are therefore complementary. The oxide layer is chemically homogenous as shown by SKPFM imaging and our ultra-thin passive layer is an efficient barrier against corrosion. (C) 2017 Elsevier B.V. All rights reserved.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Thin surface films formed on AISI 304 samples in an alkaline solution of pH = 13 are studied by atomic force microscopy (AFM), scanning Kelvin probe force microscopy (SKPFM) and electrochemical impedance spectroscopy (EIS) as a function of immersion time. The results reveal that changes on EIS diagrams correspond to topographical modifications on the sample surface as shown by AFM. Both techniques are therefore complementary. The oxide layer is chemically homogenous as shown by SKPFM imaging and our ultra-thin passive layer is an efficient barrier against corrosion. (C) 2017 Elsevier B.V. All rights reserved. |
Anselme, Karine; Wakhloo, Nayana Tusamda; Rougerie, Pablo; Pieuchot, Laurent Role of the Nucleus as a Sensor of Cell Environment Topography (Article de journal) Advanced Healthcare Materials, 7 (8), p. 1701154, 2018. @article{Anselme2018, title = {Role of the Nucleus as a Sensor of Cell Environment Topography}, author = { Karine Anselme and Nayana Tusamda Wakhloo and Pablo Rougerie and Laurent Pieuchot}, doi = {10.1002/adhm.201701154}, year = {2018}, date = {2018-04-01}, journal = {Advanced Healthcare Materials}, volume = {7}, number = {8}, pages = {1701154}, abstract = {The proper integration of biophysical cues from the cell vicinity is crucial for cells to maintain homeostasis, cooperate with other cells within the tissues, and properly fulfill their biological function. It is therefore crucial to fully understand how cells integrate these extracellular signals for tissue engineering and regenerative medicine. Topography has emerged as a prominent component of the cellular microenvironment that has pleiotropic effects on cell behavior. This progress report focuses on the recent advances in the understanding of the topography sensing mechanism with a special emphasis on the role of the nucleus. Here, recent techniques developed for monitoring the nuclear mechanics are reviewed and the impact of various topographies and their consequences on nuclear organization, gene regulation, and stem cell fate is summarized. The role of the cell nucleus as a sensor of cell-scale topography is further discussed.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The proper integration of biophysical cues from the cell vicinity is crucial for cells to maintain homeostasis, cooperate with other cells within the tissues, and properly fulfill their biological function. It is therefore crucial to fully understand how cells integrate these extracellular signals for tissue engineering and regenerative medicine. Topography has emerged as a prominent component of the cellular microenvironment that has pleiotropic effects on cell behavior. This progress report focuses on the recent advances in the understanding of the topography sensing mechanism with a special emphasis on the role of the nucleus. Here, recent techniques developed for monitoring the nuclear mechanics are reviewed and the impact of various topographies and their consequences on nuclear organization, gene regulation, and stem cell fate is summarized. The role of the cell nucleus as a sensor of cell-scale topography is further discussed. |
Ghouma, Imen; Jeguirim, Mejdi; Limousy, Lionel; Bader, Najoua; Ouederni, Abdelmottaleb; Bennici, Simona Factors Influencing NO₂ Adsorption/Reduction on Microporous Activated Carbon: Porosity vs. Surface Chemistry. (Article de journal) Materials (Basel, Switzerland), 11 (4), 2018. @article{Ghouma2018, title = {Factors Influencing NO₂ Adsorption/Reduction on Microporous Activated Carbon: Porosity vs. Surface Chemistry.}, author = { Imen Ghouma and Mejdi Jeguirim and Lionel Limousy and Najoua Bader and Abdelmottaleb Ouederni and Simona Bennici}, doi = {10.3390/ma11040622}, year = {2018}, date = {2018-04-01}, journal = {Materials (Basel, Switzerland)}, volume = {11}, number = {4}, abstract = {The textural properties and surface chemistry of different activated carbons, prepared by the chemical activation of olive stones, have been investigated in order to gain insight on the NO₂ adsorption mechanism. The parent chemical activated carbon was prepared by the impregnation of olive stones in phosphoric acid followed by thermal carbonization. Then, the textural properties and surface chemistry were modified by chemical treatments including nitric acid, sodium hydroxide and/or a thermal treatment at 900 °C. The main properties of the parent and modified activated carbons were analyzed by N₂-adsorption, scanning electron microscopy (SEM), and Fourier transform infrared spectroscopy (FTIR) techniques, in order to enlighten the modifications issued from the chemical and thermal treatments. The NO₂ adsorption capacities of the different activated carbons were measured in fixed bed experiments under 500 ppmv NO₂ concentrations at room temperature. Temperature programmed desorption (TPD) was applied after adsorption tests in order to quantify the amount of the physisorbed and chemisorbed NO₂. The obtained results showed that the development of microporosity, the presence of oxygen-free sites, and the presence of basic surface groups are key factors for the efficient adsorption of NO₂.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The textural properties and surface chemistry of different activated carbons, prepared by the chemical activation of olive stones, have been investigated in order to gain insight on the NO₂ adsorption mechanism. The parent chemical activated carbon was prepared by the impregnation of olive stones in phosphoric acid followed by thermal carbonization. Then, the textural properties and surface chemistry were modified by chemical treatments including nitric acid, sodium hydroxide and/or a thermal treatment at 900 °C. The main properties of the parent and modified activated carbons were analyzed by N₂-adsorption, scanning electron microscopy (SEM), and Fourier transform infrared spectroscopy (FTIR) techniques, in order to enlighten the modifications issued from the chemical and thermal treatments. The NO₂ adsorption capacities of the different activated carbons were measured in fixed bed experiments under 500 ppmv NO₂ concentrations at room temperature. Temperature programmed desorption (TPD) was applied after adsorption tests in order to quantify the amount of the physisorbed and chemisorbed NO₂. The obtained results showed that the development of microporosity, the presence of oxygen-free sites, and the presence of basic surface groups are key factors for the efficient adsorption of NO₂. |
Garra, Patxi; Dumur, Frederic; Gigmes, Didier; Nechab, Malek; Morlet-Savary, Fabrice; Dietlin, Celine; Gree, Simon; Fouassier, Jean Pierre; Lalevee, Jacques Metal Acetylacetonate-Bidentate Ligand Interaction (MABLI) (Photo)activated Polymerization: Toward High Performance Amine-Free, Peroxide-Free Redox Radical (Photo)initiating Systems (Article de journal) Macromolecules, 51 (7), p. 2706–2715, 2018. @article{Garra2018e, title = {Metal Acetylacetonate-Bidentate Ligand Interaction (MABLI) (Photo)activated Polymerization: Toward High Performance Amine-Free, Peroxide-Free Redox Radical (Photo)initiating Systems}, author = { Patxi Garra and Frederic Dumur and Didier Gigmes and Malek Nechab and Fabrice Morlet-Savary and Celine Dietlin and Simon Gree and Jean Pierre Fouassier and Jacques Lalevee}, doi = {10.1021/acs.macromol.8b00163}, year = {2018}, date = {2018-04-01}, journal = {Macromolecules}, volume = {51}, number = {7}, pages = {2706--2715}, abstract = {Free radical polymerization (FRP) initiation from metal acetylacetonate-bidentate ligand interaction (MABLI) under mild conditions (room temperature, under air) is discussed here for different metal centers (Mn, V, and Cu). First, without light, in MABLI systems such as V(acac)(3)/2-diphenylphosphinobenzoic acid (2dppba), Mn(acac)(3)/2dppba, or Cu(acac)(2)/2dppba, electron-rich aryl (Ar-center dot) radicals were conveniently and efficiently produced by the reaction of electron-poor acac(center dot) radicals with the iodonium salt (Iod), leading to an enhancement of pure redox (no light) polymerizations. Second, it was found that V(III)*/Iod reaction is generating aryl (Ar-center dot) radicals at a high enough rate to initiate a photopolymerization process upon mild irradiation (LED@405 nm). This reaction can be implemented in redox photoactivated systems (e.g., using three-component V(acac)(3)/2dppba/Iod systems) in order to spectacularly enhance a slow redox process from 40 degrees C exothermicity in 800 s to 93 degrees C in less than 200 s. Third, an impressive chemical bleaching (without light) was reported for the Mn(acac)(3)/2dppba reaction. Photoactivation of the Mn(acac)(3)/2dppba/Iod system led to outstanding FRP initiation efficiencies (<20 s for more than 85% C=C conversion of a low-viscosity methacrylate resin). Light enhancement of surface curing was confirmed for all the redox photoactivated polymerizations using Raman confocal microscopy. Overall, amine-free peroxide-free MABLI radical initiating systems were highly improved for safer and even more efficient redox (photoactivated) polymerizations. This original combination of redox polymerization and photopolymerization will be highly worthwhile to combine in one approach the advantages of both techniques.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Free radical polymerization (FRP) initiation from metal acetylacetonate-bidentate ligand interaction (MABLI) under mild conditions (room temperature, under air) is discussed here for different metal centers (Mn, V, and Cu). First, without light, in MABLI systems such as V(acac)(3)/2-diphenylphosphinobenzoic acid (2dppba), Mn(acac)(3)/2dppba, or Cu(acac)(2)/2dppba, electron-rich aryl (Ar-center dot) radicals were conveniently and efficiently produced by the reaction of electron-poor acac(center dot) radicals with the iodonium salt (Iod), leading to an enhancement of pure redox (no light) polymerizations. Second, it was found that V(III)*/Iod reaction is generating aryl (Ar-center dot) radicals at a high enough rate to initiate a photopolymerization process upon mild irradiation (LED@405 nm). This reaction can be implemented in redox photoactivated systems (e.g., using three-component V(acac)(3)/2dppba/Iod systems) in order to spectacularly enhance a slow redox process from 40 degrees C exothermicity in 800 s to 93 degrees C in less than 200 s. Third, an impressive chemical bleaching (without light) was reported for the Mn(acac)(3)/2dppba reaction. Photoactivation of the Mn(acac)(3)/2dppba/Iod system led to outstanding FRP initiation efficiencies (<20 s for more than 85% C=C conversion of a low-viscosity methacrylate resin). Light enhancement of surface curing was confirmed for all the redox photoactivated polymerizations using Raman confocal microscopy. Overall, amine-free peroxide-free MABLI radical initiating systems were highly improved for safer and even more efficient redox (photoactivated) polymerizations. This original combination of redox polymerization and photopolymerization will be highly worthwhile to combine in one approach the advantages of both techniques. |
Herraiz, Michael; Dubois, Marc; Batisse, Nicolas; Hajjar-Garreau, Samar; Simon, Laurent Large-scale synthesis of fluorinated graphene by rapid thermal exfoliation of highly fluorinated graphite (Article de journal) Dalton Transactions, 47 (13), p. 4596–4606, 2018. @article{Herraiz2018, title = {Large-scale synthesis of fluorinated graphene by rapid thermal exfoliation of highly fluorinated graphite}, author = { Michael Herraiz and Marc Dubois and Nicolas Batisse and Samar Hajjar-Garreau and Laurent Simon}, doi = {10.1039/c7dt04565d}, year = {2018}, date = {2018-04-01}, journal = {Dalton Transactions}, volume = {47}, number = {13}, pages = {4596--4606}, abstract = {Weakly fluorinated graphene nanosheets were efficiently prepared via fast thermal exfoliation of highly fluorinated graphite. This scalable method consists of a fast temperature increase (around 10 degrees C s(-1)) of fluorinated HOPG performed under an argon atmosphere, without any post-treatment. The mechanism of exfoliation induced by the defluorination step, evolving volatile fluorocarbons, has been highlighted thanks to thermogravimetric analysis (TGA), high temperature X-ray diffraction (HTK-XRD), X-ray Photoelectron Spectrometry (XPS) studies on temperature, and Raman and infrared spectroscopy. The advantages of the described process are its high-yield for the preparation of fluorinated graphene nanosheets, its ease of implementation and scalability. Moreover, the fluorine content drastically decreases during such a process and graphene layers are slightly functionalized, i.e. conductive contrary to the precursor.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Weakly fluorinated graphene nanosheets were efficiently prepared via fast thermal exfoliation of highly fluorinated graphite. This scalable method consists of a fast temperature increase (around 10 degrees C s(-1)) of fluorinated HOPG performed under an argon atmosphere, without any post-treatment. The mechanism of exfoliation induced by the defluorination step, evolving volatile fluorocarbons, has been highlighted thanks to thermogravimetric analysis (TGA), high temperature X-ray diffraction (HTK-XRD), X-ray Photoelectron Spectrometry (XPS) studies on temperature, and Raman and infrared spectroscopy. The advantages of the described process are its high-yield for the preparation of fluorinated graphene nanosheets, its ease of implementation and scalability. Moreover, the fluorine content drastically decreases during such a process and graphene layers are slightly functionalized, i.e. conductive contrary to the precursor. |
Odarchenko, Yaroslav; Defaux, Matthieu; Rosenthal, Martin; Akhkiamova, Azaliia; Bovsunovskaya, Polina; Melnikov, Alexey; Rodygin, Alexander; Rychkov, Andrey; Gerasimov, Kirill; Anokhin, Denis V; Zhu, Xiaomin; Ivanov, Dimitri A One Methylene Group in the Side Chain Can Alter by 90 Degrees the Orientation of a Main-Chain Liquid Crystal on a Unidirectional Substrate (Article de journal) Acs Macro Letters, 7 (4), p. 453–458, 2018. @article{Odarchenko2018, title = {One Methylene Group in the Side Chain Can Alter by 90 Degrees the Orientation of a Main-Chain Liquid Crystal on a Unidirectional Substrate}, author = { Yaroslav Odarchenko and Matthieu Defaux and Martin Rosenthal and Azaliia Akhkiamova and Polina Bovsunovskaya and Alexey Melnikov and Alexander Rodygin and Andrey Rychkov and Kirill Gerasimov and Denis V Anokhin and Xiaomin Zhu and Dimitri A. Ivanov}, doi = {10.1021/acsmacrolett.8b00044}, year = {2018}, date = {2018-04-01}, journal = {Acs Macro Letters}, volume = {7}, number = {4}, pages = {453--458}, abstract = {The mechanisms of orientation of columnar liquid crystals (LCs) on a PTFE-rubbed surface are explored on a homologous series of symmetrically substituted poly(di-n-alkylsiloxanes) (PDAS). It is shown that by increasing the side-chain length in steps of one CH2 group, the orientation of PDAS switches back and forth from perpendicular to parallel with respect to PTFE chains. These changes are sensitive to the smallest possible variation of the macromolecular structure (i.e., modification of the side chain length by just one CH2 group) reflect the alteration of the alignment mechanism identified as graphoepitaxial or epitaxial for the perpendicular and parallel orientation, respectively. The results show that two orthogonal LC orientations are realizable on the same rubbed substrate, which can open new perspectives in the field of organic and printed electronics such as multidomain LCD technology.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The mechanisms of orientation of columnar liquid crystals (LCs) on a PTFE-rubbed surface are explored on a homologous series of symmetrically substituted poly(di-n-alkylsiloxanes) (PDAS). It is shown that by increasing the side-chain length in steps of one CH2 group, the orientation of PDAS switches back and forth from perpendicular to parallel with respect to PTFE chains. These changes are sensitive to the smallest possible variation of the macromolecular structure (i.e., modification of the side chain length by just one CH2 group) reflect the alteration of the alignment mechanism identified as graphoepitaxial or epitaxial for the perpendicular and parallel orientation, respectively. The results show that two orthogonal LC orientations are realizable on the same rubbed substrate, which can open new perspectives in the field of organic and printed electronics such as multidomain LCD technology. |
Cichocka, Magdalena O; Lorgouilloux, Yannick; Smeets, Stef; Su, Jie; Wan, Wei; Caullet, Philippe; Bats, Nicolas; McCusker, Lynne B; Paillaud, Jean-Louis; Zou, Xiaodong Multidimensional Disorder in Zeolite IM-18 Revealed by Combining Transmission Electron Microscopy and X-ray Powder Diffraction Analyses (Article de journal) Crystal Growth & Design, 18 (4), p. 2441–2451, 2018. @article{Cichocka2018, title = {Multidimensional Disorder in Zeolite IM-18 Revealed by Combining Transmission Electron Microscopy and X-ray Powder Diffraction Analyses}, author = { Magdalena O. Cichocka and Yannick Lorgouilloux and Stef Smeets and Jie Su and Wei Wan and Philippe Caullet and Nicolas Bats and Lynne B. McCusker and Jean-Louis Paillaud and Xiaodong Zou}, doi = {10.1021/acs.cgd.8b00078}, year = {2018}, date = {2018-04-01}, journal = {Crystal Growth & Design}, volume = {18}, number = {4}, pages = {2441--2451}, abstract = {A new medium-pore germanosilicate, denoted IM-18, with a three-dimensional 8 x 8 x 10-ring channel system, has been prepared hydrothermally using 4-dimethylaminopyridine as an organic structure-directing agent (OSDA). Due to the presence of stacking disorder, the structure elucidation of IM-18 was challenging, and a combination of different techniques, including electron diffraction, high-resolution transmission electron microscopy (HRTEM), and Rietveld refinement using synchrotron powder diffraction data, was necessary to elucidate the details of the structure and to understand the nature of the disorder. Rotation electron diffraction data were used to determine the average structure of IM-18, HRTEM images to characterize the stacking disorder, and Rietveld refinement to locate the Ge in the framework and the OSDA occluded in the channels.}, keywords = {}, pubstate = {published}, tppubtype = {article} } A new medium-pore germanosilicate, denoted IM-18, with a three-dimensional 8 x 8 x 10-ring channel system, has been prepared hydrothermally using 4-dimethylaminopyridine as an organic structure-directing agent (OSDA). Due to the presence of stacking disorder, the structure elucidation of IM-18 was challenging, and a combination of different techniques, including electron diffraction, high-resolution transmission electron microscopy (HRTEM), and Rietveld refinement using synchrotron powder diffraction data, was necessary to elucidate the details of the structure and to understand the nature of the disorder. Rotation electron diffraction data were used to determine the average structure of IM-18, HRTEM images to characterize the stacking disorder, and Rietveld refinement to locate the Ge in the framework and the OSDA occluded in the channels. |
Aloulou, Wala; Hamza, Wiem; Aloulou, Hajer; Oun, Abdallah; Khemakhem, Sabeur; Jada, Amane; Chakraborty, Sudip; Curcio, Stefano; Amar, Raja Ben Developing of titania-smectite nanocomposites UF membrane over zeolite based ceramic support (Article de journal) Applied Clay Science, 155 , p. 20–29, 2018. @article{Aloulou2018, title = {Developing of titania-smectite nanocomposites UF membrane over zeolite based ceramic support}, author = { Wala Aloulou and Wiem Hamza and Hajer Aloulou and Abdallah Oun and Sabeur Khemakhem and Amane Jada and Sudip Chakraborty and Stefano Curcio and Raja Ben Amar}, doi = {10.1016/j.clay.2017.12.035}, year = {2018}, date = {2018-04-01}, journal = {Applied Clay Science}, volume = {155}, pages = {20--29}, abstract = {In the present work, OF ceramic membrane from smectite (Sm) nanoparticle as active layer and zeolite as a support was prepared. The nanoparticle clay powder was obtained by using a colloidal route method. Thus, titanium (IV) isopropoxide was incorporated within the organophilic layer and developed on the surface of the alumino-silicate-grains. Firstly, the nanoparticle powders were characterized by using various methods (XRD, IR, SEM-EDX and BET). Hence, the morphology and properties of the resulting membrane sintered at 900 degrees C were then determined by SEM, FTIR and BET, whereas its performance was investigated by conducting pure water permeation and application for treatment of four types of different industrial waste water. The microstructure observed from SEM showed that the separation layer has a homogenous structure with no cracks resulting in an average pore diameter of 18 nm. Furthermore, water permeability was found to vary from 1218 L.h(-1).m(-2).bar(-1) for the support before layer deposition to 80 L.h(-1).m(-2).bar(-1) after coating. This value confirms that the Sm/Z membrane is suitable for operating in ultrafiltration domain. Finally, the application to the treatment of industrial waste-waters revealed an important decrease in turbidity, color and chemical oxygen demand (COD) while the permeate flux was maintained at acceptable value. The overall data suggest that the elaborated titania-smectite nanocomposite membrane may be an effective remediation means aimed at industrial effluents treatment.}, keywords = {}, pubstate = {published}, tppubtype = {article} } In the present work, OF ceramic membrane from smectite (Sm) nanoparticle as active layer and zeolite as a support was prepared. The nanoparticle clay powder was obtained by using a colloidal route method. Thus, titanium (IV) isopropoxide was incorporated within the organophilic layer and developed on the surface of the alumino-silicate-grains. Firstly, the nanoparticle powders were characterized by using various methods (XRD, IR, SEM-EDX and BET). Hence, the morphology and properties of the resulting membrane sintered at 900 degrees C were then determined by SEM, FTIR and BET, whereas its performance was investigated by conducting pure water permeation and application for treatment of four types of different industrial waste water. The microstructure observed from SEM showed that the separation layer has a homogenous structure with no cracks resulting in an average pore diameter of 18 nm. Furthermore, water permeability was found to vary from 1218 L.h(-1).m(-2).bar(-1) for the support before layer deposition to 80 L.h(-1).m(-2).bar(-1) after coating. This value confirms that the Sm/Z membrane is suitable for operating in ultrafiltration domain. Finally, the application to the treatment of industrial waste-waters revealed an important decrease in turbidity, color and chemical oxygen demand (COD) while the permeate flux was maintained at acceptable value. The overall data suggest that the elaborated titania-smectite nanocomposite membrane may be an effective remediation means aimed at industrial effluents treatment. |
Garra, P; Morlet-Savary, F; Graff, B; Dumur, F; Monnier, V; Dietlin, C; Gigmes, D; Fouassier, J P; Lalevee, J Metal Acetylacetonate-Bidentate Ligand Interaction (MABLI) as highly efficient free radical generating systems for polymer synthesis (Article de journal) Polymer Chemistry, 9 (12), p. 1371–1378, 2018. @article{Garra2018f, title = {Metal Acetylacetonate-Bidentate Ligand Interaction (MABLI) as highly efficient free radical generating systems for polymer synthesis}, author = { P. Garra and F. Morlet-Savary and B. Graff and F. Dumur and V. Monnier and C. Dietlin and D. Gigmes and J. P. Fouassier and J. Lalevee}, doi = {10.1039/c8py00238j}, year = {2018}, date = {2018-03-01}, journal = {Polymer Chemistry}, volume = {9}, number = {12}, pages = {1371--1378}, abstract = {Metal Acetylacetonate-Bidentate Ligand Interaction (MABLI) is presented here as a new chemical mechanism for the highly efficient generation of free radicals for polymer synthesis. This MABLI process involves simultaneous ligand exchange and a change of the metal oxidation degree and is associated with the efficient release of free radicals. In conventional redox two-component radical generating systems, two criteria are required to be efficient: (1) oxidizing agents must exhibit a low bond dissociation energy (BDE) i.e. they are usually unstable (e.g. peroxides) and (2) a small difference must exist between the oxidation potential of the reducing agent and the reduction potential of the oxidation agent. In contrast, here, the criteria for efficient MABLI radical generation were energetic and geometric for both bidentate ligands and metal acetylacetonates. The strength of this approach is to use stable compounds in 2-components free radical initiating systems and to generate carbon centered radicals. Mechanistic investigations demonstrated the formation of new metal adducts by means of high-resolution mass spectroscopy (HR-ESI-MS) as well as UV-vis spectrometry. As a result of its high radical generating rate, the potential of MABLI was illustrated on the methacrylate free radical polymerization under mild conditions (room temperature, in air) and initiated with a small amount of metal acetylacetonate though it opens new perspectives for acac-like additions in organic chemistry.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Metal Acetylacetonate-Bidentate Ligand Interaction (MABLI) is presented here as a new chemical mechanism for the highly efficient generation of free radicals for polymer synthesis. This MABLI process involves simultaneous ligand exchange and a change of the metal oxidation degree and is associated with the efficient release of free radicals. In conventional redox two-component radical generating systems, two criteria are required to be efficient: (1) oxidizing agents must exhibit a low bond dissociation energy (BDE) i.e. they are usually unstable (e.g. peroxides) and (2) a small difference must exist between the oxidation potential of the reducing agent and the reduction potential of the oxidation agent. In contrast, here, the criteria for efficient MABLI radical generation were energetic and geometric for both bidentate ligands and metal acetylacetonates. The strength of this approach is to use stable compounds in 2-components free radical initiating systems and to generate carbon centered radicals. Mechanistic investigations demonstrated the formation of new metal adducts by means of high-resolution mass spectroscopy (HR-ESI-MS) as well as UV-vis spectrometry. As a result of its high radical generating rate, the potential of MABLI was illustrated on the methacrylate free radical polymerization under mild conditions (room temperature, in air) and initiated with a small amount of metal acetylacetonate though it opens new perspectives for acac-like additions in organic chemistry. |
Astafan, Amir; Benghalem, Mohammed Amine; Michelin, Laure; Rigolet, Severinne; Patarin, Joel; Pinard, Ludovic; Daou, Jean T Synthesis of hierarchical ZSM-48 nano-zeolites (Article de journal) New Journal of Chemistry, 42 (6), p. 4457–4464, 2018. @article{Astafan2018, title = {Synthesis of hierarchical ZSM-48 nano-zeolites}, author = { Amir Astafan and Mohammed Amine Benghalem and Laure Michelin and Severinne Rigolet and Joel Patarin and Ludovic Pinard and T. Jean Daou}, doi = {10.1039/c7nj04822j}, year = {2018}, date = {2018-03-01}, journal = {New Journal of Chemistry}, volume = {42}, number = {6}, pages = {4457--4464}, abstract = {Hierarchical zeolites are known to offer fast mass transfer along with size and shape selectivity compared to their conventional micron-sized zeolite counterparts. We report here the successful synthesis and characterization of a hierarchical ZSM-48 zeolite (*MRE-type structure) using a specific gemini-type surfactant that acts as dual functions template to generate at the same time micropores and mesopores. The Si/Al molar ratio of the starting gel seems to influence the nature of the obtained zeolitic phase. Pure hierarchical ZSM-48 zeolites were only obtained at a high Si/Al molar ratio of the starting gel (Si/Al = 31 to 50). The catalytic properties of these acidic catalysts were then tested in ethanol transformation into hydrocarbons.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Hierarchical zeolites are known to offer fast mass transfer along with size and shape selectivity compared to their conventional micron-sized zeolite counterparts. We report here the successful synthesis and characterization of a hierarchical ZSM-48 zeolite (*MRE-type structure) using a specific gemini-type surfactant that acts as dual functions template to generate at the same time micropores and mesopores. The Si/Al molar ratio of the starting gel seems to influence the nature of the obtained zeolitic phase. Pure hierarchical ZSM-48 zeolites were only obtained at a high Si/Al molar ratio of the starting gel (Si/Al = 31 to 50). The catalytic properties of these acidic catalysts were then tested in ethanol transformation into hydrocarbons. |
Mousawi, Assi Al; Garra, Patxi; Sallenave, Xavier; Dumur, Frederic; Toufaily, Joumana; Hamieh, Tayssir; Graff, Bernadette; Gigmes, Didier; Fouassier, Jean Pierre; Lalevee, Jacques pi-Conjugated Dithienophosphole Derivatives as High Performance Photoinitiators for 3D Printing Resins (Article de journal) Macromolecules, 51 (5), p. 1811–1821, 2018. @article{AlMousawi2018a, title = {pi-Conjugated Dithienophosphole Derivatives as High Performance Photoinitiators for 3D Printing Resins}, author = { Assi Al Mousawi and Patxi Garra and Xavier Sallenave and Frederic Dumur and Joumana Toufaily and Tayssir Hamieh and Bernadette Graff and Didier Gigmes and Jean Pierre Fouassier and Jacques Lalevee}, doi = {10.1021/acs.macromol.8b00044}, year = {2018}, date = {2018-03-01}, journal = {Macromolecules}, volume = {51}, number = {5}, pages = {1811--1821}, abstract = {Photopolymerization and 3D printing applications upon near-UV or visible light are currently limited to both rather low polymerization speed and thin layer by layer productions (below 100 mu m) using photoinitiating systems (PIS) mainly inherited from the 1990s. Filling the need for new PIS, two pi-conjugated dithienophosphole derivatives (DTPs) are synthesized and proposed as high performance near-UV and visible light photoinitiators/photoredox catalysts for both free radical polymerization (FRP) of (meth)acrylates and cationic polymerization (CP) of epoxides (e.g., using light-emitting diode (LED) at 405 nm). Astounding polymerization initiating abilities are found, and high final reactive function conversions are obtained (for multifunctional monomers). Their utilization as materials in laser write and 3D printing experiments is especially carried out with for the first time, about 2 mm 3D printed photopolymers in a one-layer approach. A full picture of the included photochemical mechanisms is additionally given. Originally, dithienophosphole derivatives are featured as metal-free photoinitiators/photoredox catalysts.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Photopolymerization and 3D printing applications upon near-UV or visible light are currently limited to both rather low polymerization speed and thin layer by layer productions (below 100 mu m) using photoinitiating systems (PIS) mainly inherited from the 1990s. Filling the need for new PIS, two pi-conjugated dithienophosphole derivatives (DTPs) are synthesized and proposed as high performance near-UV and visible light photoinitiators/photoredox catalysts for both free radical polymerization (FRP) of (meth)acrylates and cationic polymerization (CP) of epoxides (e.g., using light-emitting diode (LED) at 405 nm). Astounding polymerization initiating abilities are found, and high final reactive function conversions are obtained (for multifunctional monomers). Their utilization as materials in laser write and 3D printing experiments is especially carried out with for the first time, about 2 mm 3D printed photopolymers in a one-layer approach. A full picture of the included photochemical mechanisms is additionally given. Originally, dithienophosphole derivatives are featured as metal-free photoinitiators/photoredox catalysts. |
Baron, Marc; Morris, Jason C; Telitel, Siham; Clement, Jean-Louis; Lalevee, Jacques; Morlet-Savary, Fabrice; Spangenberg, Arnaud; Malval, Jean-Pierre; Soppera, Olivier; Gigmes, Didier; Guillaneuf, Yohann Light-Sensitive Alkoxyamines as Versatile Spatially- and Temporally-Controlled Precursors of Alkyl Radicals and Nitroxides (Article de journal) Journal of the American Chemical Society, 140 (9), p. 3339–3344, 2018. @article{Baron2018, title = {Light-Sensitive Alkoxyamines as Versatile Spatially- and Temporally-Controlled Precursors of Alkyl Radicals and Nitroxides}, author = { Marc Baron and Jason C. Morris and Siham Telitel and Jean-Louis Clement and Jacques Lalevee and Fabrice Morlet-Savary and Arnaud Spangenberg and Jean-Pierre Malval and Olivier Soppera and Didier Gigmes and Yohann Guillaneuf}, doi = {10.1021/jacs.7b12807}, year = {2018}, date = {2018-03-01}, journal = {Journal of the American Chemical Society}, volume = {140}, number = {9}, pages = {3339--3344}, abstract = {The use of UV/visible light irradiation as a means to initiate organic syntheses is increasingly attractive due to the high spatial and temporal control conferred by photochemical processes. The aim of this work is thus to demonstrate that alkoxyamines bearing a chromophore on the alkyl moiety can provide a photoprotecting group for the sensitive nitroxide functionality, that is known to degrade through redox processes. The dissociation of various photosensitive alkoxyamines was studied from 223 to 298 K under UV/visible irradiation, depending on the nature of the chromophore. In each case a rapid (typically in less than 1 h) and near-quantitative dissociation was observed. As an illustration of the interest of this approach, a pyrene-based alkoxyamine was employed for the spatially controlled coupling of polymer chains onto Si wafers to produce micropatterned surfaces.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The use of UV/visible light irradiation as a means to initiate organic syntheses is increasingly attractive due to the high spatial and temporal control conferred by photochemical processes. The aim of this work is thus to demonstrate that alkoxyamines bearing a chromophore on the alkyl moiety can provide a photoprotecting group for the sensitive nitroxide functionality, that is known to degrade through redox processes. The dissociation of various photosensitive alkoxyamines was studied from 223 to 298 K under UV/visible irradiation, depending on the nature of the chromophore. In each case a rapid (typically in less than 1 h) and near-quantitative dissociation was observed. As an illustration of the interest of this approach, a pyrene-based alkoxyamine was employed for the spatially controlled coupling of polymer chains onto Si wafers to produce micropatterned surfaces. |
Paiva, L; Fidalgo, T K S; da Costa, L P; Maia, L C; Balan, L; Anselme, K; Ploux, L; Thire, R M S M Antibacterial properties and compressive strength of new one-step preparation silver nanoparticles in glass ionomer cements (NanoAg-GIC). (Article de journal) Journal of dentistry, 69 , p. 102–109, 2018. @article{Paiva2018, title = {Antibacterial properties and compressive strength of new one-step preparation silver nanoparticles in glass ionomer cements (NanoAg-GIC).}, author = {L Paiva and T K S Fidalgo and L P da Costa and L C Maia and L Balan and K Anselme and L Ploux and R M S M Thire}, doi = {10.1016/j.jdent.2017.12.003}, year = {2018}, date = {2018-02-01}, journal = {Journal of dentistry}, volume = {69}, pages = {102--109}, abstract = {OBJECTIVES: This work aimed (1) to develop polyacid formulations by the one-step photoreduction of silver nanoparticles (AgNP) in a polyacrylate solution of conventional glass ionomer cement (GIC), imparting antibacterial activity; and (2) to evaluate handling and mechanical properties of experimental ionomers in comparison to a commercially available conventional GIC. METHODS: Formulations with increasing sub-stoichiometric amounts of AgNO3 were monitored during continuous UV light exposure by UV-vis spectroscopy and analyzed by transmission electron microscopy. The resulted synthesis of formulations containing small and disperse spherical nanoparticles (6 nm) were used to design the experimental nano-silver glass ionomer cements (NanoAg-GIC). The cements were characterized as to net setting time and compressive strength according to ISO 9917-1:2007 specifications. The antibacterial activity of these cements was assessed by Ag+ diffusion tests on nutritive agar plates (E. coli) and by MTT assay (S. mutans). RESULTS: The higher concentration of silver (0.50% by mass) in the matrix of NanoAg-GIC allowed viable net setting time and increased in 32% compressive strength of the experimental cement. All groups containing AgNP induced statistically significant E. coli growth inhibition zones (p-value <.05), indicating diffusion of Ag+ ions on the material surroundings. Metabolic activity of S. mutans grown on NanoAg-GIG with higher concentration of silver was significantly affected compared to control (p-value <.01). CONCLUSIONS: Silver nanoparticles one-step preparation in polyacrylate solution allowed the production of highly bioactive water-based cements within suitable parameters for clinical use and with large potential of dental and biomedical application.}, keywords = {}, pubstate = {published}, tppubtype = {article} } OBJECTIVES: This work aimed (1) to develop polyacid formulations by the one-step photoreduction of silver nanoparticles (AgNP) in a polyacrylate solution of conventional glass ionomer cement (GIC), imparting antibacterial activity; and (2) to evaluate handling and mechanical properties of experimental ionomers in comparison to a commercially available conventional GIC. METHODS: Formulations with increasing sub-stoichiometric amounts of AgNO3 were monitored during continuous UV light exposure by UV-vis spectroscopy and analyzed by transmission electron microscopy. The resulted synthesis of formulations containing small and disperse spherical nanoparticles (6 nm) were used to design the experimental nano-silver glass ionomer cements (NanoAg-GIC). The cements were characterized as to net setting time and compressive strength according to ISO 9917-1:2007 specifications. The antibacterial activity of these cements was assessed by Ag+ diffusion tests on nutritive agar plates (E. coli) and by MTT assay (S. mutans). RESULTS: The higher concentration of silver (0.50% by mass) in the matrix of NanoAg-GIC allowed viable net setting time and increased in 32% compressive strength of the experimental cement. All groups containing AgNP induced statistically significant E. coli growth inhibition zones (p-value <.05), indicating diffusion of Ag+ ions on the material surroundings. Metabolic activity of S. mutans grown on NanoAg-GIG with higher concentration of silver was significantly affected compared to control (p-value <.01). CONCLUSIONS: Silver nanoparticles one-step preparation in polyacrylate solution allowed the production of highly bioactive water-based cements within suitable parameters for clinical use and with large potential of dental and biomedical application. |
Ronchi, Laura; Ryzhikov, Andrey; Nouali, Habiba; Daou, Jean T; Patarin, Joel Energetic Performances of Pure-Silica DDR Zeolite by High-Pressure Intrusion-Extrusion of Electrolyte Aqueous Solutions: A Shock-Absorber with Huge Absorbed Energy (Article de journal) Journal of Physical Chemistry C, 122 (5), p. 2726–2733, 2018. @article{Ronchi2018b, title = {Energetic Performances of Pure-Silica DDR Zeolite by High-Pressure Intrusion-Extrusion of Electrolyte Aqueous Solutions: A Shock-Absorber with Huge Absorbed Energy}, author = { Laura Ronchi and Andrey Ryzhikov and Habiba Nouali and T. Jean Daou and Joel Patarin}, doi = {10.1021/acs.jpcc.7b10995}, year = {2018}, date = {2018-02-01}, journal = {Journal of Physical Chemistry C}, volume = {122}, number = {5}, pages = {2726--2733}, abstract = {Pure-silica DDR-type zeolite (zeosil) displays a porosity composed of two kinds of small cages (pore opening of 4-6 MR) and of a large nonadecahedron cage with pore windows of 8 MR. In order to study the energetic performances of this hydrophobic material by high-pressure intrusion-extrusion experiments, water and 10 and 20 M LiCl aqueous solutions were chosen as nonwetting liquids. The intrusion pressure increases from 60 to 357 MPa when using water and 20 M LiCl aqueous solution, respectively. The latter pressure is the highest ever found for a zeosil-based system. It is associated with a large intruded volume of 0.26 mL/g, which is close to the total theoretical porosity of the DDR structure. The corresponding "DDR-20 M LiCl aqueous solution" system demonstrates mainly shock-absorber behavior, and both features (high intrusion pressure and large intruded volume) lead to the highest amount of absorbed mechanical energy for such systems: 93 and 61 J/g for the first and the following intrusion cycles, respectively. After-intrusion extrusion of LiCl aqueous solutions and depending on the concentration of the solution or the number of the intrusion-extrusion cycles, slight distortions of the DDR unit cell are clearly evidenced by XRD and Si-29 MAS NMR analyses. Two possible explanations are advanced to explain such distortions.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Pure-silica DDR-type zeolite (zeosil) displays a porosity composed of two kinds of small cages (pore opening of 4-6 MR) and of a large nonadecahedron cage with pore windows of 8 MR. In order to study the energetic performances of this hydrophobic material by high-pressure intrusion-extrusion experiments, water and 10 and 20 M LiCl aqueous solutions were chosen as nonwetting liquids. The intrusion pressure increases from 60 to 357 MPa when using water and 20 M LiCl aqueous solution, respectively. The latter pressure is the highest ever found for a zeosil-based system. It is associated with a large intruded volume of 0.26 mL/g, which is close to the total theoretical porosity of the DDR structure. The corresponding "DDR-20 M LiCl aqueous solution" system demonstrates mainly shock-absorber behavior, and both features (high intrusion pressure and large intruded volume) lead to the highest amount of absorbed mechanical energy for such systems: 93 and 61 J/g for the first and the following intrusion cycles, respectively. After-intrusion extrusion of LiCl aqueous solutions and depending on the concentration of the solution or the number of the intrusion-extrusion cycles, slight distortions of the DDR unit cell are clearly evidenced by XRD and Si-29 MAS NMR analyses. Two possible explanations are advanced to explain such distortions. |
Zhang, Jing; Zivic, Nicolas; Dumur, Frederic; Xiao, Pu; Graff, Bernadette; Fouassier, Jean Pierre; Gigmes, Didier; Lalevee, Jacques N-[2-(Dimethylamino)ethyl]-1,8-naphthalimide derivatives as photoinitiators under LEDs (Article de journal) Polymer Chemistry, 9 (8), p. 994–1003, 2018. @article{Zhang2018a, title = {N-[2-(Dimethylamino)ethyl]-1,8-naphthalimide derivatives as photoinitiators under LEDs}, author = {Jing Zhang and Nicolas Zivic and Frederic Dumur and Pu Xiao and Bernadette Graff and Jean Pierre Fouassier and Didier Gigmes and Jacques Lalevee}, doi = {10.1039/c8py00055g}, year = {2018}, date = {2018-02-01}, journal = {Polymer Chemistry}, volume = {9}, number = {8}, pages = {994--1003}, abstract = {Four N-[2-(dimethylamino) ethyl]-1,8-naphthalimide derivatives (ANNs) with different substituents (bromo group, primary amine, secondary amine, and tertiary amine) in the naphthalimide skeleton have been synthesized and can be used as one-component free radical photoinitiators or incorporated into multicomponent photoinitiating systems for free radical or cationic photopolymerization under the irradiation of various LEDs. ANN2 (with secondary amine substituent) or ANN3 (with tertiary amine substituent) alone is capable of initiating the free radical polymerization of acrylates under a LED at 405 nm while ANN0 (with bromo substituent) or ANN1 (with primary amine substituent) does not work. When combined with various additives (e.g. iodonium salt, N-vinylcarbazole, chloro triazine, or tertiary amine), most of the ANN1-3 based multi-component photoinitiating systems are efficient in free radical photopolymerization at 385 nm, 405 nm, 455 nm, 470 nm and even under a low-intensity polychromatic visible light (from a halogen lamp) with the final conversions being higher than 60% (even more efficient than commercial photoinitiators bisacylphosphine oxide and camphorquinone). In addition, ANN1-3 based photoinitiating systems also exhibit a high efficiency for cationic photopolymerization of epoxides upon diverse LEDs. The ANN2 based photoinitiating system can also be used for the synthesis of interpenetrated polymer networks and adapted for 3D printing. The photochemical mechanisms of the ANN based systems have been comprehensively investigated and discussed in detail.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Four N-[2-(dimethylamino) ethyl]-1,8-naphthalimide derivatives (ANNs) with different substituents (bromo group, primary amine, secondary amine, and tertiary amine) in the naphthalimide skeleton have been synthesized and can be used as one-component free radical photoinitiators or incorporated into multicomponent photoinitiating systems for free radical or cationic photopolymerization under the irradiation of various LEDs. ANN2 (with secondary amine substituent) or ANN3 (with tertiary amine substituent) alone is capable of initiating the free radical polymerization of acrylates under a LED at 405 nm while ANN0 (with bromo substituent) or ANN1 (with primary amine substituent) does not work. When combined with various additives (e.g. iodonium salt, N-vinylcarbazole, chloro triazine, or tertiary amine), most of the ANN1-3 based multi-component photoinitiating systems are efficient in free radical photopolymerization at 385 nm, 405 nm, 455 nm, 470 nm and even under a low-intensity polychromatic visible light (from a halogen lamp) with the final conversions being higher than 60% (even more efficient than commercial photoinitiators bisacylphosphine oxide and camphorquinone). In addition, ANN1-3 based photoinitiating systems also exhibit a high efficiency for cationic photopolymerization of epoxides upon diverse LEDs. The ANN2 based photoinitiating system can also be used for the synthesis of interpenetrated polymer networks and adapted for 3D printing. The photochemical mechanisms of the ANN based systems have been comprehensively investigated and discussed in detail. |
Bonardi, A H; Dumur, F; Grant, T M; Noirbent, G; Gigmes, D; Lessard, B H; Fouassier, J - P; Lalevee, J High Performance Near-Infrared (NIR) Photoinitiating Systems Operating under Low Light Intensity and in the Presence of Oxygen (Article de journal) Macromolecules, 51 (4), p. 1314–1324, 2018. @article{Bonardi2018, title = {High Performance Near-Infrared (NIR) Photoinitiating Systems Operating under Low Light Intensity and in the Presence of Oxygen}, author = {A H Bonardi and F Dumur and T M Grant and G Noirbent and D Gigmes and B H Lessard and J - P Fouassier and J Lalevee}, doi = {10.1021/acs.macromol.8b00051}, year = {2018}, date = {2018-02-01}, journal = {Macromolecules}, volume = {51}, number = {4}, pages = {1314--1324}, abstract = {Photopolymerization under near-infrared (NIR) light is challenging due to the low energy of the absorbed photon but, if successful, presents significant advantages. For example, this lower energy wavelength is safer than UV light that is currently the standard photocuring light source. Also, NIR allows for a deeper light penetration within the material and therefore resulting in a more complete curing of thicker materials containing fillers for access to composites. In this study, we report the use of three component systems for the NIR photopolymerization of methacrylates: (1) a dye used as a photosensitizer in the NIR range, (2) an iodonium salt as a photoinitiator for the free radical polymerization of the (meth)acrylates, and (3) a phosphine to prevent polymerization inhibition due to the oxygen and to regenerate the dye upon irradiation. Several NIR-absorbing dyes such as a cyanine borate and a silicon phthalocyanine are presented and studied. Systems using borate dyes resulted in methacrylate monomer conversion over 80% in air. We report three types of irradiation system: low-power LED at 660 and 780 nm as well as a higher power laser diode at 785 nm. The excellent performance reported in this work is due to the crucial role of the added phosphine.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Photopolymerization under near-infrared (NIR) light is challenging due to the low energy of the absorbed photon but, if successful, presents significant advantages. For example, this lower energy wavelength is safer than UV light that is currently the standard photocuring light source. Also, NIR allows for a deeper light penetration within the material and therefore resulting in a more complete curing of thicker materials containing fillers for access to composites. In this study, we report the use of three component systems for the NIR photopolymerization of methacrylates: (1) a dye used as a photosensitizer in the NIR range, (2) an iodonium salt as a photoinitiator for the free radical polymerization of the (meth)acrylates, and (3) a phosphine to prevent polymerization inhibition due to the oxygen and to regenerate the dye upon irradiation. Several NIR-absorbing dyes such as a cyanine borate and a silicon phthalocyanine are presented and studied. Systems using borate dyes resulted in methacrylate monomer conversion over 80% in air. We report three types of irradiation system: low-power LED at 660 and 780 nm as well as a higher power laser diode at 785 nm. The excellent performance reported in this work is due to the crucial role of the added phosphine. |
Mortada, Boushra; Chaplais, Gerald; Veremeienko, Vasyl; Nouali, Habiba; Marichal, Claire; Patarin, Joel Energetic Performances of ZIF-8 Derivatives: Impact of the Substitution (Me, Cl, or Br) on Imidazolate Linker (Article de journal) Journal of Physical Chemistry C, 122 (7), p. 3846–3855, 2018. @article{Mortada2018, title = {Energetic Performances of ZIF-8 Derivatives: Impact of the Substitution (Me, Cl, or Br) on Imidazolate Linker}, author = {Boushra Mortada and Gerald Chaplais and Vasyl Veremeienko and Habiba Nouali and Claire Marichal and Joel Patarin}, doi = {10.1021/acs.jpcc.7b08999}, year = {2018}, date = {2018-02-01}, journal = {Journal of Physical Chemistry C}, volume = {122}, number = {7}, pages = {3846--3855}, abstract = {The energetic performances of three isomorphic ZIF materials, i.e., ZIF-8_CH3 (Basolite Z1200), ZIF-8_Cl, and ZIF-8_Br, of SOD topology are studied with high-pressure intrusion extrusion experiments using water and aqueous electrolyte solutions (KCl 4 M and LiCl 20 M) as nonwetting liquids. This work represents an important progress in the field of energetic applications, as the "ZIF-8_Cl-LiCl 20 M" system exhibits a spring behavior with a stored energy of 77 J g(-1). To the best of our knowledge, this is the highest value for the stored energy obtained using intrusion-extrusion experiments. Experimental results reveal that the intrusion pressure increases with the addition of electrolytes. The systems evolve from a bumper to a shock-absorber or spring behavior with the decrease in the strength of the interactions between the cation of the salt and the imidazolate linker. This explains the bumper or rather the shock-absorber behavior observed for the "ZIF-8_Br-KCl 4 M" and "ZIF-8_CH3-LiCl 20 M" systems compared to the spring behavior observed with the other systems reported in this work.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The energetic performances of three isomorphic ZIF materials, i.e., ZIF-8_CH3 (Basolite Z1200), ZIF-8_Cl, and ZIF-8_Br, of SOD topology are studied with high-pressure intrusion extrusion experiments using water and aqueous electrolyte solutions (KCl 4 M and LiCl 20 M) as nonwetting liquids. This work represents an important progress in the field of energetic applications, as the "ZIF-8_Cl-LiCl 20 M" system exhibits a spring behavior with a stored energy of 77 J g(-1). To the best of our knowledge, this is the highest value for the stored energy obtained using intrusion-extrusion experiments. Experimental results reveal that the intrusion pressure increases with the addition of electrolytes. The systems evolve from a bumper to a shock-absorber or spring behavior with the decrease in the strength of the interactions between the cation of the salt and the imidazolate linker. This explains the bumper or rather the shock-absorber behavior observed for the "ZIF-8_Br-KCl 4 M" and "ZIF-8_CH3-LiCl 20 M" systems compared to the spring behavior observed with the other systems reported in this work. |
Oras, Sven; Vlassov, Sergei; Berholts, Marta; Lohmus, Runno; Mougin, Karine Tuning adhesion forces between functionalized gold colloidal nanoparticles and silicon AFM tips: role of ligands and capillary forces (Article de journal) Beilstein Journal of Nanotechnology, 9 , p. 660–670, 2018. @article{Oras2018, title = {Tuning adhesion forces between functionalized gold colloidal nanoparticles and silicon AFM tips: role of ligands and capillary forces}, author = {Sven Oras and Sergei Vlassov and Marta Berholts and Runno Lohmus and Karine Mougin}, doi = {10.3762/bjnano.9.61}, year = {2018}, date = {2018-02-01}, journal = {Beilstein Journal of Nanotechnology}, volume = {9}, pages = {660--670}, abstract = {Adhesion forces between functionalized gold colloidal nanoparticles (Au NPs) and scanning probe microscope silicon tips were experimentally investigated by atomic force microscopy (AFM) equipped with PeakForce QNM (Quantitative Nanoscale Mechanics) module. Au NPs were synthesized by a seed-mediated process and then functionalized with thiols containing different functional groups: amino, hydroxy, methoxy, carboxy, methyl, and thiol. Adhesion measurements showed strong differences between NPs and silicon tip depending on the nature of the tail functional group. The dependence of the adhesion on ligand density for different thiols with identical functional tail-group was also demonstrated. The calculated contribution of the van der Waals (vdW) forces between particles was in good agreement with experimentally measured adhesive values. In addition, the adhesion forces were evaluated between flat Au films functionalized with the same molecular components and silicon tips to exclude the effect of particle shape on the adhesion values. Although adhesion values on flat substrates were higher than on their nanoparticle counterparts, the dependance on functional groups remained the same.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Adhesion forces between functionalized gold colloidal nanoparticles (Au NPs) and scanning probe microscope silicon tips were experimentally investigated by atomic force microscopy (AFM) equipped with PeakForce QNM (Quantitative Nanoscale Mechanics) module. Au NPs were synthesized by a seed-mediated process and then functionalized with thiols containing different functional groups: amino, hydroxy, methoxy, carboxy, methyl, and thiol. Adhesion measurements showed strong differences between NPs and silicon tip depending on the nature of the tail functional group. The dependence of the adhesion on ligand density for different thiols with identical functional tail-group was also demonstrated. The calculated contribution of the van der Waals (vdW) forces between particles was in good agreement with experimentally measured adhesive values. In addition, the adhesion forces were evaluated between flat Au films functionalized with the same molecular components and silicon tips to exclude the effect of particle shape on the adhesion values. Although adhesion values on flat substrates were higher than on their nanoparticle counterparts, the dependance on functional groups remained the same. |
Garra, Patxi; Carre, Meline; Dumur, Frederic; Morlet-Savary, Fabrice; Dietlin, Celine; Gigmes, Didier; Fouassier, Jean-Pierre; Lalevee, Jacques Copper-Based (Photo)redox Initiating Systems Systems for Interpenetrating Polymer Network as Highly Efficient Preparation (Article de journal) Macromolecules, 51 (3), p. 679–688, 2018. @article{Garra2018b, title = {Copper-Based (Photo)redox Initiating Systems Systems for Interpenetrating Polymer Network as Highly Efficient Preparation}, author = {Patxi Garra and Meline Carre and Frederic Dumur and Fabrice Morlet-Savary and Celine Dietlin and Didier Gigmes and Jean-Pierre Fouassier and Jacques Lalevee}, doi = {10.1021/acs.macromol.7b02491}, year = {2018}, date = {2018-02-01}, journal = {Macromolecules}, volume = {51}, number = {3}, pages = {679--688}, abstract = {Simultaneous redox free radical polymerization (FRP) and redox cationic polymerization (CP) are combined for the synthesis of methacrylate/diepoxide interpenetrating polymer networks (IPN). At first, the Cu(acac)(2)/phosphine/iodonium salt operates according to the principles of free radical promoted cationic polymerization (FRPCP). A photoactivation of the reaction for that system was necessary to enhance the mild methacrylate and diepoxide conversions. Second and at least, two complementary copper catalytic cycles are used simultaneously: the recently developed Cu(II)/reducing agent/peroxide FRP system combined with the older Cu(II)/reducing agent/iodonium salt redox CP system. For this latter hybrid system, outstanding efficiency was observed with more than 90% of epoxy functions conversion for the cationic difunctional monomers and 78% conversion for the vinylic functions conversion for difunctional monomers. The radical and cation generations are discussed in order to fill the interrogations raised by the experimental results. The relevance of dual FRP/CP in IPN synthesis is fully demonstrated. The performance of the hybrid copper catalytic system is remarkable to overcome the oxygen inhibition; i.e., almost no oxygen inhibited layers are observed compared to the >60 mu m inhibited layer obtained with a reference redox FRP such as amine/BPO.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Simultaneous redox free radical polymerization (FRP) and redox cationic polymerization (CP) are combined for the synthesis of methacrylate/diepoxide interpenetrating polymer networks (IPN). At first, the Cu(acac)(2)/phosphine/iodonium salt operates according to the principles of free radical promoted cationic polymerization (FRPCP). A photoactivation of the reaction for that system was necessary to enhance the mild methacrylate and diepoxide conversions. Second and at least, two complementary copper catalytic cycles are used simultaneously: the recently developed Cu(II)/reducing agent/peroxide FRP system combined with the older Cu(II)/reducing agent/iodonium salt redox CP system. For this latter hybrid system, outstanding efficiency was observed with more than 90% of epoxy functions conversion for the cationic difunctional monomers and 78% conversion for the vinylic functions conversion for difunctional monomers. The radical and cation generations are discussed in order to fill the interrogations raised by the experimental results. The relevance of dual FRP/CP in IPN synthesis is fully demonstrated. The performance of the hybrid copper catalytic system is remarkable to overcome the oxygen inhibition; i.e., almost no oxygen inhibited layers are observed compared to the >60 mu m inhibited layer obtained with a reference redox FRP such as amine/BPO. |
Wang, N; Meissner, M V; MacKinnon, N; Luchnikov, V; Mager, D; Korvink, J G Fast prototyping of microtubes with embedded sensing elements made possible with an inkjet printing and rolling process (Article de journal) Journal of Micromechanics and Microengineering, 28 (2), p. 025003, 2018. @article{Wang2018, title = {Fast prototyping of microtubes with embedded sensing elements made possible with an inkjet printing and rolling process}, author = { N. Wang and M. V. Meissner and N. MacKinnon and V. Luchnikov and D. Mager and J. G. Korvink}, doi = {10.1088/1361-6439/aa7a61}, year = {2018}, date = {2018-02-01}, journal = {Journal of Micromechanics and Microengineering}, volume = {28}, number = {2}, pages = {025003}, abstract = {We present a new fabrication process to create sub-mm micro tubes with embedded conductive patterns. Based on common 2D patterning techniques and a specially designed rolling process, it achieves 3D structures featuring potentially complex, embedded electrical, mechanical and micro-fluidic functions. We demonstrate the advantage in creating freeform electrical conductors around sub-mm tubes, such as needed for a tube-integrated micro heater. The production of the 2D patterns is flexible, and we demonstrate that both additive manufacturing (fast, accessible) and conventional micro-fabrication processes (cleanroom, wafer-scale) are compatible with the rolling process. To adapt the rolling process for high frequency applications, the patterned tracks can be directly electroplated, with good adhesion, to reduce electrical resistance. For the first time, we achieve saddle-geometry NMR micro detectors. They feature 100 mu m wide, 10 mu m thick conductive tracks on 25 mu m thick polyimide film, and were successfully tested in a 500 MHz (11.7 T) NMR spectrometer. Using a 620 mu m diameter coil, we measured the single-shot SNR of deionized water sample, which corresponded to a mole sensitivity of 18.78 nmolHz-1/2, and a water line shape of 1.52/26.8/37.3 Hz (50, 0.55, 0.11% of the maximum height) from a sample volume of only 82 nl.}, keywords = {}, pubstate = {published}, tppubtype = {article} } We present a new fabrication process to create sub-mm micro tubes with embedded conductive patterns. Based on common 2D patterning techniques and a specially designed rolling process, it achieves 3D structures featuring potentially complex, embedded electrical, mechanical and micro-fluidic functions. We demonstrate the advantage in creating freeform electrical conductors around sub-mm tubes, such as needed for a tube-integrated micro heater. The production of the 2D patterns is flexible, and we demonstrate that both additive manufacturing (fast, accessible) and conventional micro-fabrication processes (cleanroom, wafer-scale) are compatible with the rolling process. To adapt the rolling process for high frequency applications, the patterned tracks can be directly electroplated, with good adhesion, to reduce electrical resistance. For the first time, we achieve saddle-geometry NMR micro detectors. They feature 100 mu m wide, 10 mu m thick conductive tracks on 25 mu m thick polyimide film, and were successfully tested in a 500 MHz (11.7 T) NMR spectrometer. Using a 620 mu m diameter coil, we measured the single-shot SNR of deionized water sample, which corresponded to a mole sensitivity of 18.78 nmolHz-1/2, and a water line shape of 1.52/26.8/37.3 Hz (50, 0.55, 0.11% of the maximum height) from a sample volume of only 82 nl. |
Kunstman, Pawel; Coulon, Joel; Kolmykov, Oleksii; Moussa, Hatem; Balan, Lavinia; Medjahdi, Ghouti; Lulek, Janina; Schneider, Raphael One step synthesis of bright luminescent core/shell CdTexS1-x/ZnS quantum dots emitting from the visible to the near infrared (Article de journal) Journal of Luminescence, 194 , p. 760–767, 2018. @article{Kunstman2018, title = {One step synthesis of bright luminescent core/shell CdTexS1-x/ZnS quantum dots emitting from the visible to the near infrared}, author = { Pawel Kunstman and Joel Coulon and Oleksii Kolmykov and Hatem Moussa and Lavinia Balan and Ghouti Medjahdi and Janina Lulek and Raphael Schneider}, doi = {10.1016/j.jlumin.2017.09.047}, year = {2018}, date = {2018-02-01}, journal = {Journal of Luminescence}, volume = {194}, pages = {760--767}, abstract = {A one-pot synthetic approach was developed to prepare water-dispersible core/shell CdTexS1-x/ZnS QDs using CdCl2, Zn(OAc)(2), NaHTe and 3-mercaptopropionic acid (MPA) as starting materials. Sulfide S2- ions produced from the partial decomposition of MPA associate to CdTe nuclei to form an alloyed CdTexS1-x core before reacting with Zn2+ ions to generate the ZnS shell. The photoluminescence (PL) of CdTexS1-x/ZnS QDs QDs can be adjusted from the green to the near-infrared region by varying the ratio of precursors or the reaction time. The formation of core/shell CdTexS1-x/ZnS structure was confirmed by high resolution transmission electron microscopy and X-ray diffraction studies. The highly luminescent QDs (PL quantum yields up to 35%) exhibit good stability in aqueous solution and low cytotoxicity towards Kluyveromyces bulgaricus cells. Bioconjugation of CdTexS1-x/ZnS QDs with (D)-(+)-galactose was successfully applied for the fluorescent imaging of the yeast cells.}, keywords = {}, pubstate = {published}, tppubtype = {article} } A one-pot synthetic approach was developed to prepare water-dispersible core/shell CdTexS1-x/ZnS QDs using CdCl2, Zn(OAc)(2), NaHTe and 3-mercaptopropionic acid (MPA) as starting materials. Sulfide S2- ions produced from the partial decomposition of MPA associate to CdTe nuclei to form an alloyed CdTexS1-x core before reacting with Zn2+ ions to generate the ZnS shell. The photoluminescence (PL) of CdTexS1-x/ZnS QDs QDs can be adjusted from the green to the near-infrared region by varying the ratio of precursors or the reaction time. The formation of core/shell CdTexS1-x/ZnS structure was confirmed by high resolution transmission electron microscopy and X-ray diffraction studies. The highly luminescent QDs (PL quantum yields up to 35%) exhibit good stability in aqueous solution and low cytotoxicity towards Kluyveromyces bulgaricus cells. Bioconjugation of CdTexS1-x/ZnS QDs with (D)-(+)-galactose was successfully applied for the fluorescent imaging of the yeast cells. |
Ghimbeu, Camelia Matei; Gorka, Joanna; Simone, Virgine; Simonin, Loic; Martinet, Sebastien; Vix-Guterl, Cathie Insights on the Na+ ion storage mechanism in hard carbon: Discrimination between the porosity, surface functional groups and defects (Article de journal) Nano Energy, 44 , p. 327–335, 2018. @article{Ghimbeu2018, title = {Insights on the Na+ ion storage mechanism in hard carbon: Discrimination between the porosity, surface functional groups and defects}, author = { Camelia Matei Ghimbeu and Joanna Gorka and Virgine Simone and Loic Simonin and Sebastien Martinet and Cathie Vix-Guterl}, doi = {10.1016/j.nanoen.2017.12.013}, year = {2018}, date = {2018-02-01}, journal = {Nano Energy}, volume = {44}, pages = {327--335}, abstract = {Sodium ion batteries (SIBs) using hard carbon as negative electrode hold the promise of being low cost alternative to lithium ion batteries (LiBs). However, the Na+ storage mechanism in hard carbons is not fully understood yet and the attribution of Na storage in the sloping and plateau regions of the sodiation/desodiation curves remains still controversial. The current work employs N-2, Kr and CO2 gases to correctly assess the changes in hard carbon porosity induced by different pyrolysis temperature of cellulose. The sloping capacity was found to decrease with the decrease of the specific area of ultramicropores measurable only by CO2 adsorption, while the plateau capacity demonstrated an opposite behavior. The high temperature derived carbons (> 1400 degrees C) present no porosity which disqualifies the attribution of plateau region to the adsorption of Na+ in the nanopores but rather the insertion between the pseudo-graphitic domains. Temperature programmed desorption coupled with mass spectrometry (TPD-MS) was performed to determine the nature and the quantity of oxygen surface functional groups followed by oxygen chemisorptions to assess the amount of carbon edge defects expressed by active surface area (ASA) values. A decrease in the amount of oxygen groups and active surface area with the increase of the pyrolysis temperature was observed which is accompanied by a decrease of the sloping capacity. These results shed light in the storage mechanisms, the sloping region being ascribed mainly to the interaction of Na+ with carbon edge defects and adsorption in the microporosity while the plateau region assigned to the intercalation of Na+ in the pseudo-graphitic nanodomains.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Sodium ion batteries (SIBs) using hard carbon as negative electrode hold the promise of being low cost alternative to lithium ion batteries (LiBs). However, the Na+ storage mechanism in hard carbons is not fully understood yet and the attribution of Na storage in the sloping and plateau regions of the sodiation/desodiation curves remains still controversial. The current work employs N-2, Kr and CO2 gases to correctly assess the changes in hard carbon porosity induced by different pyrolysis temperature of cellulose. The sloping capacity was found to decrease with the decrease of the specific area of ultramicropores measurable only by CO2 adsorption, while the plateau capacity demonstrated an opposite behavior. The high temperature derived carbons (> 1400 degrees C) present no porosity which disqualifies the attribution of plateau region to the adsorption of Na+ in the nanopores but rather the insertion between the pseudo-graphitic domains. Temperature programmed desorption coupled with mass spectrometry (TPD-MS) was performed to determine the nature and the quantity of oxygen surface functional groups followed by oxygen chemisorptions to assess the amount of carbon edge defects expressed by active surface area (ASA) values. A decrease in the amount of oxygen groups and active surface area with the increase of the pyrolysis temperature was observed which is accompanied by a decrease of the sloping capacity. These results shed light in the storage mechanisms, the sloping region being ascribed mainly to the interaction of Na+ with carbon edge defects and adsorption in the microporosity while the plateau region assigned to the intercalation of Na+ in the pseudo-graphitic nanodomains. |
Sibeaud, Mathilde; Paz-Simon, De H; Croutxe-Barghorn, C; Rigolet, S; Michelin, L; Lebeau, B; Vidal, L; Albouy, P - A; Chemtob, A Scaling-up of mesoporous silica films via an eco-efficient UV processing method. Part 1: Photoinduced mesostructuration (Article de journal) Microporous and Mesoporous Materials, 257 , p. 42–50, 2018. @article{Sibeaud2018a, title = {Scaling-up of mesoporous silica films via an eco-efficient UV processing method. Part 1: Photoinduced mesostructuration}, author = { Mathilde Sibeaud and H. De Paz-Simon and C. Croutxe-Barghorn and S. Rigolet and L. Michelin and B. Lebeau and L. Vidal and P. -. A. Albouy and A. Chemtob}, doi = {10.1016/j.micromeso.2017.08.017}, year = {2018}, date = {2018-02-01}, journal = {Microporous and Mesoporous Materials}, volume = {257}, pages = {42--50}, abstract = {Designing sustainable and industrially viable processing methods to synthesize ordered mesoporous films is a necessary condition to tap their full potential of applications. In order to respond to this challenge, well-established photoacid-catalyzed sol-gel photopolymerization has been harnessed to prepare large (>100 cm(2)) and micrometer-thick porous silica films possessing a 2D hexagonal mesostructure. Our UV irradiation system consists of two inexpensive and low radiant power fluorescent UV tubes (3 mW cm(-2), 280-380 nm) enclosed in a hygrometric chamber. Precise conditions to promote copolymer/silica hybrid film mesostructuration have been determined as regards relative humidity, film thickness and templating agent concentration. The mesostructured films have been analyzed using an extensive range of techniques including electron microscopy, grazing-incidence small-angle X-ray scattering (GISAXS), and N-2 sorption measurements, and solid-state NMR spectroscopy. Mesoporous silica films with a specific surface area up to 314 m(2) g(-1) have been achieved with a very low level of microporosity. Coupling of X-ray diffraction (XRD) and FTIR spectroscopy has enabled to shed light into the photoinduced self-assembly mechanism. (C) 2017 Elsevier Inc. All rights reserved.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Designing sustainable and industrially viable processing methods to synthesize ordered mesoporous films is a necessary condition to tap their full potential of applications. In order to respond to this challenge, well-established photoacid-catalyzed sol-gel photopolymerization has been harnessed to prepare large (>100 cm(2)) and micrometer-thick porous silica films possessing a 2D hexagonal mesostructure. Our UV irradiation system consists of two inexpensive and low radiant power fluorescent UV tubes (3 mW cm(-2), 280-380 nm) enclosed in a hygrometric chamber. Precise conditions to promote copolymer/silica hybrid film mesostructuration have been determined as regards relative humidity, film thickness and templating agent concentration. The mesostructured films have been analyzed using an extensive range of techniques including electron microscopy, grazing-incidence small-angle X-ray scattering (GISAXS), and N-2 sorption measurements, and solid-state NMR spectroscopy. Mesoporous silica films with a specific surface area up to 314 m(2) g(-1) have been achieved with a very low level of microporosity. Coupling of X-ray diffraction (XRD) and FTIR spectroscopy has enabled to shed light into the photoinduced self-assembly mechanism. (C) 2017 Elsevier Inc. All rights reserved. |
Wang, Kuan-Hsun; Zan, Hsiao-Wen; Soppera, Olivier The zinc-loss effect and mobility enhancement of DUV-patterned sol-gel IGZO thin-film transistors (Article de journal) Semiconductor Science and Technology, 33 (3), p. 035003, 2018. @article{Wang2018a, title = {The zinc-loss effect and mobility enhancement of DUV-patterned sol-gel IGZO thin-film transistors}, author = {Kuan-Hsun Wang and Hsiao-Wen Zan and Olivier Soppera}, doi = {10.1088/1361-6641/aaa611}, year = {2018}, date = {2018-01-01}, journal = {Semiconductor Science and Technology}, volume = {33}, number = {3}, pages = {035003}, abstract = {We investigate the composition of the DUV-patterned sol-gel indium gallium zinc oxide (IGZO) thin-film transistors (TFTs) and observe a significant zinc loss effect during developing when the DUV exposure is insufficient. The zinc loss, however, is beneficial for increasing the mobility. Reducing zinc to indium composition ratio from 0.5 to 0.02 can effectively increase mobility from 0.27 to 7.30 cm(2) V-1 s (-1) when the gallium to indium ratio is fixed as 0.25 and the post annealing process is fixed as 300 degrees C for 2 h. On the other hand, an IGO TFT fails to deliver a uniform film and a reproducible TFT performance, revealing the critical role of zinc in forming homogeneous IGZO TFTs.}, keywords = {}, pubstate = {published}, tppubtype = {article} } We investigate the composition of the DUV-patterned sol-gel indium gallium zinc oxide (IGZO) thin-film transistors (TFTs) and observe a significant zinc loss effect during developing when the DUV exposure is insufficient. The zinc loss, however, is beneficial for increasing the mobility. Reducing zinc to indium composition ratio from 0.5 to 0.02 can effectively increase mobility from 0.27 to 7.30 cm(2) V-1 s (-1) when the gallium to indium ratio is fixed as 0.25 and the post annealing process is fixed as 300 degrees C for 2 h. On the other hand, an IGO TFT fails to deliver a uniform film and a reproducible TFT performance, revealing the critical role of zinc in forming homogeneous IGZO TFTs. |
Ryzhikov, A; Nouali, H; Daou, T J; Patarin, J A drastic influence of the anion nature and concentration on high pressure intrusion-extrusion of electrolyte solutions in Silicalite-1. (Article de journal) Physical chemistry chemical physics : PCCP, 2018. @article{Ryzhikov2018a, title = {A drastic influence of the anion nature and concentration on high pressure intrusion-extrusion of electrolyte solutions in Silicalite-1.}, author = {A Ryzhikov and H Nouali and T J Daou and J Patarin}, doi = {10.1039/c7cp06520e}, year = {2018}, date = {2018-01-01}, journal = {Physical chemistry chemical physics : PCCP}, abstract = {High pressure intrusion-extrusion of concentrated solutions of sodium salts in a pure-silica MFI-type zeolite (Silicalite-1) was studied for potential applications in mechanical energy absorption and storage. It was discovered that the anion nature has a drastic influence on the behavior and the energetic performances of "Silicalite-1 - concentrated Na+X- solution" systems, where X = Cl-, Br-, I-, NO2-, NO3-, ClO4- and CrO42-. In the case of NaNO2, NaClO4, Na2CrO4, and NaI a combination of bumper and shock-absorber behaviors with a partial irreversible solution intrusion was observed, whereas a fully reversible spring behavior is demonstrated for the intrusion-extrusion of NaBr, NaCl and NaNO3 solutions. In comparison with water, the intrusion pressure increases for all the solutions except for NaClO4 one. The irreversibility of intrusion decreases with a dilution rate, and the behavior of the corresponding systems with diluted solutions becomes very close. The variation of the system behavior and intrusion pressure values can be related to a different affinity of the corresponding anions for the pores of Silicalite-1. The samples before and after intrusion-extrusion experiments were characterized using several structural and physicochemical methods (XRD, TGA, solid-state NMR, and N2 physisorption), but no significant structural difference was observed.}, keywords = {}, pubstate = {published}, tppubtype = {article} } High pressure intrusion-extrusion of concentrated solutions of sodium salts in a pure-silica MFI-type zeolite (Silicalite-1) was studied for potential applications in mechanical energy absorption and storage. It was discovered that the anion nature has a drastic influence on the behavior and the energetic performances of "Silicalite-1 - concentrated Na+X- solution" systems, where X = Cl-, Br-, I-, NO2-, NO3-, ClO4- and CrO42-. In the case of NaNO2, NaClO4, Na2CrO4, and NaI a combination of bumper and shock-absorber behaviors with a partial irreversible solution intrusion was observed, whereas a fully reversible spring behavior is demonstrated for the intrusion-extrusion of NaBr, NaCl and NaNO3 solutions. In comparison with water, the intrusion pressure increases for all the solutions except for NaClO4 one. The irreversibility of intrusion decreases with a dilution rate, and the behavior of the corresponding systems with diluted solutions becomes very close. The variation of the system behavior and intrusion pressure values can be related to a different affinity of the corresponding anions for the pores of Silicalite-1. The samples before and after intrusion-extrusion experiments were characterized using several structural and physicochemical methods (XRD, TGA, solid-state NMR, and N2 physisorption), but no significant structural difference was observed. |
Daukiya, L; Nair, M N; Hajjar-Garreau, S; Vonau, F; Aubel, D; Bubendorff, J L; Cranney, M; Denys, E; Florentin, A; Reiter, G; Simon, L Highly n-doped graphene generated through intercalated terbium atoms (Article de journal) Physical Review B, 97 (3), 2018. @article{Daukiya2018, title = {Highly n-doped graphene generated through intercalated terbium atoms}, author = {L Daukiya and M N Nair and S Hajjar-Garreau and F Vonau and D Aubel and J L Bubendorff and M Cranney and E Denys and A Florentin and G Reiter and L Simon}, doi = {10.1103/PhysRevB.97.035309}, year = {2018}, date = {2018-01-01}, journal = {Physical Review B}, volume = {97}, number = {3}, abstract = {We obtained highly n-type doped graphene by intercalating terbium atoms between graphene and SiC(0001) through appropriate annealing in ultrahigh vacuum. After terbium intercalation angle-resolved-photoelectron spectroscopy (ARPES) showed a drastic change in the band structure around the K points of the Brillouin zone: the well-known conical dispersion band of a graphene monolayer was superposed by a second conical dispersion band of a graphene monolayer with an electron density reaching 10(15) cm(-2). In addition, we demonstrate that atom intercalation proceeds either below the buffer layer or between the buffer layer and the monolayer graphene. The intercalation of terbium below a pure buffer layer led to the formation of a highly n-doped graphene monolayer decoupled from the SiC substrate, as evidenced by ARPES and x-ray photoelectron spectroscopy measurements. The band structure of this highly n-doped monolayer graphene showed a kink (a deviation from the linear dispersion of the Dirac cone), which has been associated with an electron-phonon coupling constant one order of magnitude larger than those usually obtained for graphene with intercalated alkali metals.}, keywords = {}, pubstate = {published}, tppubtype = {article} } We obtained highly n-type doped graphene by intercalating terbium atoms between graphene and SiC(0001) through appropriate annealing in ultrahigh vacuum. After terbium intercalation angle-resolved-photoelectron spectroscopy (ARPES) showed a drastic change in the band structure around the K points of the Brillouin zone: the well-known conical dispersion band of a graphene monolayer was superposed by a second conical dispersion band of a graphene monolayer with an electron density reaching 10(15) cm(-2). In addition, we demonstrate that atom intercalation proceeds either below the buffer layer or between the buffer layer and the monolayer graphene. The intercalation of terbium below a pure buffer layer led to the formation of a highly n-doped graphene monolayer decoupled from the SiC substrate, as evidenced by ARPES and x-ray photoelectron spectroscopy measurements. The band structure of this highly n-doped monolayer graphene showed a kink (a deviation from the linear dispersion of the Dirac cone), which has been associated with an electron-phonon coupling constant one order of magnitude larger than those usually obtained for graphene with intercalated alkali metals. |
Bouaouina, B; Besnard, A; Abaidia, S E; Airoudj, A; Bensouici, F Correlation between mechanical and microstructural properties of molybdenum nitride thin films deposited on silicon by reactive RF magnetron discharge (Article de journal) Surface & Coatings Technology, 333 , p. 32–38, 2018. @article{Bouaouina2018, title = {Correlation between mechanical and microstructural properties of molybdenum nitride thin films deposited on silicon by reactive RF magnetron discharge}, author = {B Bouaouina and A Besnard and S E Abaidia and A Airoudj and F Bensouici}, doi = {10.1016/j.surfcoat.2017.10.028}, year = {2018}, date = {2018-01-01}, journal = {Surface & Coatings Technology}, volume = {333}, pages = {32--38}, abstract = {Molybdenum nitride thin films were deposited on (100) silicon substrates by R.F. magnetron sputtering of a Mo target in a (Ar-N-2) gas mixtures. The films were studied by Scanning Electron Microscopy (SEM), Energy Dispersive Spectroscopy (EDS) and X-ray diffraction. The nanomechanical properties have been determined by nanoindentation and Peak-Force Quantitative Nanomechanical Mapping (PF-QNM). The total internal stresses were determined by curvature measurements and the Stoney formula. As thin film composition influences the morphology, the stress state and the mechanical properties, modifications are expected in this study where the nitrogen content is tuned. The film exhibits a polycrystalline structure with preferred orientation along (111) plane. The increase of the nitrogen content in the coating (N/Mo = 1.1) induces a broadening of the full width at half maximum (FWHM) of the (111) diffraction peak, which is attributed to the presence of smaller crystallites. The residual stress and mechanical properties variation were correlated to the structural transition from gamma-Mo2N to hexagonal and cubic MoN. The results show a good agreement between the nanomechanical properties obtained by nanoindentation and PF-QNM.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Molybdenum nitride thin films were deposited on (100) silicon substrates by R.F. magnetron sputtering of a Mo target in a (Ar-N-2) gas mixtures. The films were studied by Scanning Electron Microscopy (SEM), Energy Dispersive Spectroscopy (EDS) and X-ray diffraction. The nanomechanical properties have been determined by nanoindentation and Peak-Force Quantitative Nanomechanical Mapping (PF-QNM). The total internal stresses were determined by curvature measurements and the Stoney formula. As thin film composition influences the morphology, the stress state and the mechanical properties, modifications are expected in this study where the nitrogen content is tuned. The film exhibits a polycrystalline structure with preferred orientation along (111) plane. The increase of the nitrogen content in the coating (N/Mo = 1.1) induces a broadening of the full width at half maximum (FWHM) of the (111) diffraction peak, which is attributed to the presence of smaller crystallites. The residual stress and mechanical properties variation were correlated to the structural transition from gamma-Mo2N to hexagonal and cubic MoN. The results show a good agreement between the nanomechanical properties obtained by nanoindentation and PF-QNM. |
Garra, Patxi; Graff, Bernadette; Morlet-Savary, Fabrice; Dietlin, Celine; Becht, Jean-Michel; Fouassier, Jean-Pierre; Lalevee, Jacques Charge Transfer Complexes as Pan-Scaled Photoinitiating Systems: From 50 mu m 3D Printed Polymers at 405 nm to Extremely Deep Photopolymerization (31 cm) (Article de journal) Macromolecules, 51 (1), p. 57–70, 2018. @article{Garra2018, title = {Charge Transfer Complexes as Pan-Scaled Photoinitiating Systems: From 50 mu m 3D Printed Polymers at 405 nm to Extremely Deep Photopolymerization (31 cm)}, author = {Patxi Garra and Bernadette Graff and Fabrice Morlet-Savary and Celine Dietlin and Jean-Michel Becht and Jean-Pierre Fouassier and Jacques Lalevee}, doi = {10.1021/acs.macromol.7b02185}, year = {2018}, date = {2018-01-01}, journal = {Macromolecules}, volume = {51}, number = {1}, pages = {57--70}, abstract = {Charge transfer complexes (CTC) between N-aromatic amines (donors) and iodonium salts (acceptors) are used here as photoinitiating systems (PIS) for the polymerization of clear methacrylate formulations under a 405 nm LED irradiation. Outstandingly, a complete spatial and temporal resolution is kept for 50 mu m resolved 3D printed photopolymers at 40S nm (50 mu m being the size of the printing laser used here). Photo curing of a high thickness (31 cm) is also possible. The photopolymerization propagation is rationalized and interpreted from both experimental (using thermal imaging experiments) and predicted data. An experimental/molecular modeling study also attempts to rationalize the CTC structure/reactivity/efficiency relationships. These systems are commercially available, stable, and metal-free and have a low toxicity.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Charge transfer complexes (CTC) between N-aromatic amines (donors) and iodonium salts (acceptors) are used here as photoinitiating systems (PIS) for the polymerization of clear methacrylate formulations under a 405 nm LED irradiation. Outstandingly, a complete spatial and temporal resolution is kept for 50 mu m resolved 3D printed photopolymers at 40S nm (50 mu m being the size of the printing laser used here). Photo curing of a high thickness (31 cm) is also possible. The photopolymerization propagation is rationalized and interpreted from both experimental (using thermal imaging experiments) and predicted data. An experimental/molecular modeling study also attempts to rationalize the CTC structure/reactivity/efficiency relationships. These systems are commercially available, stable, and metal-free and have a low toxicity. |
Pinaud, Julien; Trinh, Thi Kim Hoang; Sauvanier, David; Placet, Emeline; Songsee, Sriprapai; Lacroix-Desmazes, Patrick; Becht, Jean-Michel; Tarablsi, Bassam; Lalevee, Jacques; Pichavant, Loic; Heroguez, Valerie; Chemtob, Abraham In Situ Generated Ruthenium-Arene Catalyst for Photoactivated Ring-Opening Metathesis Polymerization through Photolatent N-Heterocyclic Carbene Ligand (Article de journal) Chemistry-a European Journal, 24 (2), p. 337–341, 2018. @article{Pinaud2018, title = {In Situ Generated Ruthenium-Arene Catalyst for Photoactivated Ring-Opening Metathesis Polymerization through Photolatent N-Heterocyclic Carbene Ligand}, author = {Julien Pinaud and Thi Kim Hoang Trinh and David Sauvanier and Emeline Placet and Sriprapai Songsee and Patrick Lacroix-Desmazes and Jean-Michel Becht and Bassam Tarablsi and Jacques Lalevee and Loic Pichavant and Valerie Heroguez and Abraham Chemtob}, doi = {10.1002/chem.201705145}, year = {2018}, date = {2018-01-01}, journal = {Chemistry-a European Journal}, volume = {24}, number = {2}, pages = {337--341}, abstract = {1,3-Bis(mesityl)imidazolium tetraphenylborate (IMesH(+) BPh4-) can be synthesized in one step by anion metathesis between the corresponding imidazolium chloride and sodium tetraphenylborate. In the presence of 2-isopropylthioxanthone (sensitizer), an IMes N-heterocyclic carbene (NHC) ligand can be photogenerated under irradiation at 365nm through coupled electron/proton transfer reactions. By combining this tandem NHC photogenerator system with metathesis inactive [RuCl2(p-cymene)](2) precatalyst, the highly active RuCl2(p-cymene)(IMes) complex can be formed in situ, enabling a complete ring-opening metathesis polymerization (ROMP) of norbornene in the matter of minutes at room temperature. To the best of our knowledge, this is the first example of a photogenerated NHC. Its exploitation in photoROMP has resulted in a simplified process compared to current photocatalysts, because only stable commercial or easily synthesized reagents are required.}, keywords = {}, pubstate = {published}, tppubtype = {article} } 1,3-Bis(mesityl)imidazolium tetraphenylborate (IMesH(+) BPh4-) can be synthesized in one step by anion metathesis between the corresponding imidazolium chloride and sodium tetraphenylborate. In the presence of 2-isopropylthioxanthone (sensitizer), an IMes N-heterocyclic carbene (NHC) ligand can be photogenerated under irradiation at 365nm through coupled electron/proton transfer reactions. By combining this tandem NHC photogenerator system with metathesis inactive [RuCl2(p-cymene)](2) precatalyst, the highly active RuCl2(p-cymene)(IMes) complex can be formed in situ, enabling a complete ring-opening metathesis polymerization (ROMP) of norbornene in the matter of minutes at room temperature. To the best of our knowledge, this is the first example of a photogenerated NHC. Its exploitation in photoROMP has resulted in a simplified process compared to current photocatalysts, because only stable commercial or easily synthesized reagents are required. |
Zhao, Jiacheng; Lu, Mingxia; Lai, Haiwang; Lu, Hongxu; Lalevée, Jacques; Barner-Kowollik, Christopher; Stenzel, Martina H; Xiao, Pu Delivery of Amonafide from Fructose-Coated Nanodiamonds by Oxime Ligation for the Treatment of Human Breast Cancer (Article de journal) Biomacromolecules, 19 (2), p. 481-489, 2018, (PMID: 29316394). @article{Zhao2018, title = {Delivery of Amonafide from Fructose-Coated Nanodiamonds by Oxime Ligation for the Treatment of Human Breast Cancer}, author = {Jiacheng Zhao and Mingxia Lu and Haiwang Lai and Hongxu Lu and Jacques Lalevée and Christopher Barner-Kowollik and Martina H Stenzel and Pu Xiao}, url = {https://doi.org/10.1021/acs.biomac.7b01592}, doi = {10.1021/acs.biomac.7b01592}, year = {2018}, date = {2018-01-01}, journal = {Biomacromolecules}, volume = {19}, number = {2}, pages = {481-489}, abstract = {The introduction of a strategy toward polymer/nanodiamond hybrids with high polymer grafting density and accessible polymer structural characterization is of critical importance for nanodiamonds’ surface modification and bioagent attachment for their biomedical application. Here, we report a glycopolymer/nanodiamond hybrid drug delivery system, which was prepared by grafting amonafide-conjugated glycopolymers onto the surface of nanodiamonds via oxime ligation. Poly(1-O-methacryloyl-2,3:4,5-di-O-isopropylidene-β-d-fructopyranose)-b-poly(3-vinylbenzaldehyde-co-methyl methacrylate), featuring pendant aldehyde groups, is prepared via RAFT polymerization. The anticancer drug amonafide is conjugated to the polymer chains via imine chemistry, resulting in acid-degradable imine linkages. The obtained amonafide-conjugated glycopolymers are subsequently grafted onto the surface of aminooxy-functionalized nanodiamonds via oxime ligation. The molecular weight of the conjugated polymers is characterized by size-exclusion chromatography (SEC), while the successful conjugation and corresponding grafting density is assessed by nuclear magnetic resonance (NMR), Fourier transform infrared spectroscopy (FTIR), and thermogravimetric aanalysis (TGA). Our results indicate that the mass percentage of amonafide in the polymer chains is around 17% and the surface density of polymer chains is 0.24 molecules/nm2. The prepared drug delivery system has a hydrodynamic size around 380 nm with low PDI (0.3) and can effectively deliver amonafide into breast cancer cell and significantly inhibit the cancer cell viability. In 2D cell culture models, the IC50 values of ND-Polymer-AMF delivery system (7.19 μM for MCF-7; 4.92 μM for MDA-MB-231) are lower than those of free amonafide (11.23 μM for MCF-7; 13.98 μM for MDA-MB-231). An inhibited cell viability of nanodiamonds/polymer delivery system is also observed in 3D spheroids’ models, suggesting that polymer-diamonds hybrid materials can be promising platforms for breast cancer therapy.}, note = {PMID: 29316394}, keywords = {}, pubstate = {published}, tppubtype = {article} } The introduction of a strategy toward polymer/nanodiamond hybrids with high polymer grafting density and accessible polymer structural characterization is of critical importance for nanodiamonds’ surface modification and bioagent attachment for their biomedical application. Here, we report a glycopolymer/nanodiamond hybrid drug delivery system, which was prepared by grafting amonafide-conjugated glycopolymers onto the surface of nanodiamonds via oxime ligation. Poly(1-O-methacryloyl-2,3:4,5-di-O-isopropylidene-β-d-fructopyranose)-b-poly(3-vinylbenzaldehyde-co-methyl methacrylate), featuring pendant aldehyde groups, is prepared via RAFT polymerization. The anticancer drug amonafide is conjugated to the polymer chains via imine chemistry, resulting in acid-degradable imine linkages. The obtained amonafide-conjugated glycopolymers are subsequently grafted onto the surface of aminooxy-functionalized nanodiamonds via oxime ligation. The molecular weight of the conjugated polymers is characterized by size-exclusion chromatography (SEC), while the successful conjugation and corresponding grafting density is assessed by nuclear magnetic resonance (NMR), Fourier transform infrared spectroscopy (FTIR), and thermogravimetric aanalysis (TGA). Our results indicate that the mass percentage of amonafide in the polymer chains is around 17% and the surface density of polymer chains is 0.24 molecules/nm2. The prepared drug delivery system has a hydrodynamic size around 380 nm with low PDI (0.3) and can effectively deliver amonafide into breast cancer cell and significantly inhibit the cancer cell viability. In 2D cell culture models, the IC50 values of ND-Polymer-AMF delivery system (7.19 μM for MCF-7; 4.92 μM for MDA-MB-231) are lower than those of free amonafide (11.23 μM for MCF-7; 13.98 μM for MDA-MB-231). An inhibited cell viability of nanodiamonds/polymer delivery system is also observed in 3D spheroids’ models, suggesting that polymer-diamonds hybrid materials can be promising platforms for breast cancer therapy. |
Quéméner, Frédéric Le; Subervie, Daniel; Morlet-Savary, Fabrice; Lalevée, Jacques; Lansalot, Muriel; Bourgeat-Lami, Elodie; Lacôte, Emmanuel Visible-Light Emulsion Photopolymerization of Styrene (Article de journal) Angew. Chem. Int. Ed., 57 (4), p. 957–961, 2018, ISSN: 1521-3773. @article{LeQuemener2018, title = {Visible-Light Emulsion Photopolymerization of Styrene}, author = {Frédéric Le Quéméner and Daniel Subervie and Fabrice Morlet-Savary and Jacques Lalevée and Muriel Lansalot and Elodie Bourgeat-Lami and Emmanuel Lacôte}, url = {http://dx.doi.org/10.1002/anie.201710488}, issn = {1521-3773}, year = {2018}, date = {2018-01-01}, journal = {Angew. Chem. Int. Ed.}, volume = {57}, number = {4}, pages = {957--961}, abstract = {The photopolymerization of styrene in emulsion is achieved in a conventional double-wall reactor equipped with a LED ribbon coiled around the external glass wall. Styrene mixed to acridine orange is added to the water phase containing sodium dodecyl sulfate, a water-soluble N-heterocyclic carbene-borane and disulfide, and irradiated. Highly stable latexes are obtained, with particles up to a diameter of 300 nm. The ability to reach such large particle sizes via a photochemical process in a dispersed medium is due to the use of visible light: the photons in the visible range are less scattered by larger objects and thus penetrate and initiate better the polymerizations. They are also greener and cheaper to produce via LEDs, and much safer than UVs. The method presented does not require any specific glassware; it works at lower temperature and delivers larger particles compared to thermal processes at similar solids contents and surfactant concentrations.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The photopolymerization of styrene in emulsion is achieved in a conventional double-wall reactor equipped with a LED ribbon coiled around the external glass wall. Styrene mixed to acridine orange is added to the water phase containing sodium dodecyl sulfate, a water-soluble N-heterocyclic carbene-borane and disulfide, and irradiated. Highly stable latexes are obtained, with particles up to a diameter of 300 nm. The ability to reach such large particle sizes via a photochemical process in a dispersed medium is due to the use of visible light: the photons in the visible range are less scattered by larger objects and thus penetrate and initiate better the polymerizations. They are also greener and cheaper to produce via LEDs, and much safer than UVs. The method presented does not require any specific glassware; it works at lower temperature and delivers larger particles compared to thermal processes at similar solids contents and surfactant concentrations. |
Ronchi, Laura; Ryzhikov, Andrey; Nouali, Habiba; Daou, Jean T; Albrecht, Sebastien; Patarin, Joel Extra large pore opening CFI and DON-type zeosils for mechanical energy storage (Article de journal) Microporous and Mesoporous Materials, 255 , p. 211–219, 2018. @article{Ronchi2018a, title = {Extra large pore opening CFI and DON-type zeosils for mechanical energy storage}, author = {Laura Ronchi and Andrey Ryzhikov and Habiba Nouali and Jean T Daou and Sebastien Albrecht and Joel Patarin}, doi = {10.1016/j.micromeso.2017.07.039}, year = {2018}, date = {2018-01-01}, journal = {Microporous and Mesoporous Materials}, volume = {255}, pages = {211--219}, abstract = {The energetic performances of pure silica CFI and DON-type zeolites (zeosils) were studied by intrusion extrusion experiments in water and LiCl aqueous solutions at different concentrations. For both zeosils, characterized by a 1D channel system with 14 MR pore openings, when water is used as nonwetting liquid a perfect reversible spring behavior is observed with an intrusion pressure of 75 and 26 MPa, respectively. The lower value for the DON-type structure is probably due to a larger pore aperture. The intrusion pressures in both cases rise considerably with the LiCl concentration, but the doubling of the salt concentration from 10 to 20 M leads only to a slight increase of the intrusion pressure. The maximal stored energy achieves 14.6 and 6.8 J/g for CFI and DON-type zeosil-based systems, respectively. The zeolite samples were characterized before and after intrusion-extrusion experiments by XRD, SEM, N-2 adsorption-desorption, TG and NMR analysis in order to get a better understanding of the influence of these intrusion-extrusion experiments on the CFI and DON-type structures. (C) 2017 Elsevier Inc. All rights reserved.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The energetic performances of pure silica CFI and DON-type zeolites (zeosils) were studied by intrusion extrusion experiments in water and LiCl aqueous solutions at different concentrations. For both zeosils, characterized by a 1D channel system with 14 MR pore openings, when water is used as nonwetting liquid a perfect reversible spring behavior is observed with an intrusion pressure of 75 and 26 MPa, respectively. The lower value for the DON-type structure is probably due to a larger pore aperture. The intrusion pressures in both cases rise considerably with the LiCl concentration, but the doubling of the salt concentration from 10 to 20 M leads only to a slight increase of the intrusion pressure. The maximal stored energy achieves 14.6 and 6.8 J/g for CFI and DON-type zeosil-based systems, respectively. The zeolite samples were characterized before and after intrusion-extrusion experiments by XRD, SEM, N-2 adsorption-desorption, TG and NMR analysis in order to get a better understanding of the influence of these intrusion-extrusion experiments on the CFI and DON-type structures. (C) 2017 Elsevier Inc. All rights reserved. |
Slesinski, Adam; Matei-Ghimbeu, Camelia; Fic, Krzysztof; Beguin, Francois; Frackowiak, Elzbieta Self-buffered pH at carbon surfaces in aqueous supercapacitors (Article de journal) Carbon, 129 , p. 758–765, 2018. @article{Slesinski2018, title = {Self-buffered pH at carbon surfaces in aqueous supercapacitors}, author = { Adam Slesinski and Camelia Matei-Ghimbeu and Krzysztof Fic and Francois Beguin and Elzbieta Frackowiak}, doi = {10.1016/j.carbon.2017.12.101}, year = {2018}, date = {2018-01-01}, journal = {Carbon}, volume = {129}, pages = {758--765}, abstract = {This paper presents a unique strategy aiming at extending the operational voltage range in super-capacitor working in the neutral aqueous electrolyte. In-depth analysis of the equilibria formed at the carbon/electrolyte interface gives the possibility to reach 1.8 V with excellent reversibility during cycling. To reach the goal, the donor - acceptor nature of carbon electrode surface has been taken into consideration. Controlled oxidation of electrode materials coupled with ammonia adsorption have been realized in order to adjust the optimal equilibrium conditions. Nitric acid oxidation of carbon leads to the formation of electrochemically active acidic sites promoting adsorption of ammonia. Modification with ammonia results in the introduction of self-controlled pH gradient within the capacitor system and formation of protective layer on electrodes, responsible for higher overpotentials of solvent decomposition. This, in turn, allows capacitor operation at higher voltages. Furthermore, this configuration eliminates the need for physical separation of ions (such as an ion-exchange membrane) to decelerate their mixing and improves the power density of the device. (C) 2017 The Authors. Published by Elsevier Ltd.}, keywords = {}, pubstate = {published}, tppubtype = {article} } This paper presents a unique strategy aiming at extending the operational voltage range in super-capacitor working in the neutral aqueous electrolyte. In-depth analysis of the equilibria formed at the carbon/electrolyte interface gives the possibility to reach 1.8 V with excellent reversibility during cycling. To reach the goal, the donor - acceptor nature of carbon electrode surface has been taken into consideration. Controlled oxidation of electrode materials coupled with ammonia adsorption have been realized in order to adjust the optimal equilibrium conditions. Nitric acid oxidation of carbon leads to the formation of electrochemically active acidic sites promoting adsorption of ammonia. Modification with ammonia results in the introduction of self-controlled pH gradient within the capacitor system and formation of protective layer on electrodes, responsible for higher overpotentials of solvent decomposition. This, in turn, allows capacitor operation at higher voltages. Furthermore, this configuration eliminates the need for physical separation of ions (such as an ion-exchange membrane) to decelerate their mixing and improves the power density of the device. (C) 2017 The Authors. Published by Elsevier Ltd. |
Ulku, Irem; Morlet-Savary, Fabrice; Lalevee, Jacques; Acar, Havva Yagci Homogenous photopolymerization of acrylic monomers initiated with ZnO-methacrylate in non-aqueous medium and production of luminescent nanocomposites (Article de journal) Polymer Chemistry, 9 (7), p. 828–833, 2018. @article{Ulku2018, title = {Homogenous photopolymerization of acrylic monomers initiated with ZnO-methacrylate in non-aqueous medium and production of luminescent nanocomposites}, author = { Irem Ulku and Fabrice Morlet-Savary and Jacques Lalevee and Havva Yagci Acar}, doi = {10.1039/c7py02030a}, year = {2018}, date = {2018-01-01}, journal = {Polymer Chemistry}, volume = {9}, number = {7}, pages = {828--833}, abstract = {Luminescent ZnO/methacrylic acid was demonstrated as an active photoinitiator in the free radical polymerization of vinyl monomers in bulk and in organic solvent without a protic solvent or a co-catalyst, producing luminescent nanocomposites for the first time. Excitation between 320 and 390 nm provided the best results but PEGDA was also successfully initiated at 400-500 nm.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Luminescent ZnO/methacrylic acid was demonstrated as an active photoinitiator in the free radical polymerization of vinyl monomers in bulk and in organic solvent without a protic solvent or a co-catalyst, producing luminescent nanocomposites for the first time. Excitation between 320 and 390 nm provided the best results but PEGDA was also successfully initiated at 400-500 nm. |
Conder, Joanna; Marino, Cyril; Novak, Petr; Villevieille, Claire Do imaging techniques add real value to the development of better post-Li-ion batteries? (Article de journal) Journal of Materials Chemistry A, 6 (8), p. 3304–3327, 2018. @article{Conder2018, title = {Do imaging techniques add real value to the development of better post-Li-ion batteries?}, author = {Joanna Conder and Cyril Marino and Petr Novak and Claire Villevieille}, doi = {10.1039/c7ta10622j}, year = {2018}, date = {2018-01-01}, journal = {Journal of Materials Chemistry A}, volume = {6}, number = {8}, pages = {3304--3327}, abstract = {Imaging techniques are increasingly used to study Li-ion batteries and, in particular, post-Li-ion batteries such as Li-S batteries, Na-ion batteries, and all-solid-state batteries. Results that appear impressive owing to good image design and reconstruction are frequently published in high-impact-factor journals; however, questions have arisen about the added value of such results and the information they reveal about reaction mechanisms occurring in batteries during operation and/or degradation. We present here a review of imaging techniques and the knowledge acquired from these techniques for three systems: Li-S batteries, Na-ion batteries, and all-solid-state batteries. There are always advantages and disadvantages associated with these techniques, but beam damage remains the bottleneck to characterization. This factor needs to be considered seriously in order to obtain valuable outcomes that will enable improvements of battery performance and lifetime.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Imaging techniques are increasingly used to study Li-ion batteries and, in particular, post-Li-ion batteries such as Li-S batteries, Na-ion batteries, and all-solid-state batteries. Results that appear impressive owing to good image design and reconstruction are frequently published in high-impact-factor journals; however, questions have arisen about the added value of such results and the information they reveal about reaction mechanisms occurring in batteries during operation and/or degradation. We present here a review of imaging techniques and the knowledge acquired from these techniques for three systems: Li-S batteries, Na-ion batteries, and all-solid-state batteries. There are always advantages and disadvantages associated with these techniques, but beam damage remains the bottleneck to characterization. This factor needs to be considered seriously in order to obtain valuable outcomes that will enable improvements of battery performance and lifetime. |
Garra, P; Morlet-Savary, F; Graff, B; Dumur, F; Monnier, V; Dietlin, C; Gigmes, D; Fouassier, J P; Lalevee, J Metal Acetylacetonate-Bidentate Ligand Interaction (MABLI) as highly efficient free radical generating systems for polymer synthesis (Article de journal) Polym. Chem., 9 , p. 1371-1378, 2018. @article{Garra2018c, title = {Metal Acetylacetonate-Bidentate Ligand Interaction (MABLI) as highly efficient free radical generating systems for polymer synthesis}, author = {P Garra and F Morlet-Savary and B Graff and F Dumur and V Monnier and C Dietlin and D Gigmes and J P Fouassier and J Lalevee}, url = {http://dx.doi.org/10.1039/C8PY00238J}, doi = {10.1039/C8PY00238J}, year = {2018}, date = {2018-01-01}, journal = {Polym. Chem.}, volume = {9}, pages = {1371-1378}, publisher = {The Royal Society of Chemistry}, abstract = {Metal Acetylacetonate-Bidentate Ligand Interaction (MABLI) is presented here as a new chemical mechanism for the highly efficient generation of free radicals for polymer synthesis. This MABLI process involves simultaneous ligand exchange and a change of the metal oxidation degree and is associated with the efficient release of free radicals. In conventional redox two-component radical generating systems, two criteria are required to be efficient: (1) oxidizing agents must exhibit a low bond dissociation energy (BDE) i.e. they are usually unstable (e.g. peroxides) and (2) a small difference must exist between the oxidation potential of the reducing agent and the reduction potential of the oxidation agent. In contrast, here, the criteria for efficient MABLI radical generation were energetic and geometric for both bidentate ligands and metal acetylacetonates. The strength of this approach is to use stable compounds in 2-components free radical initiating systems and to generate carbon centered radicals. Mechanistic investigations demonstrated the formation of new metal adducts by means of high-resolution mass spectroscopy (HR-ESI-MS) as well as UV-vis spectrometry. As a result of its high radical generating rate, the potential of MABLI was illustrated on the methacrylate free radical polymerization under mild conditions (room temperature, in air) and initiated with a small amount of metal acetylacetonate though it opens new perspectives for acac-like additions in organic chemistry.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Metal Acetylacetonate-Bidentate Ligand Interaction (MABLI) is presented here as a new chemical mechanism for the highly efficient generation of free radicals for polymer synthesis. This MABLI process involves simultaneous ligand exchange and a change of the metal oxidation degree and is associated with the efficient release of free radicals. In conventional redox two-component radical generating systems, two criteria are required to be efficient: (1) oxidizing agents must exhibit a low bond dissociation energy (BDE) i.e. they are usually unstable (e.g. peroxides) and (2) a small difference must exist between the oxidation potential of the reducing agent and the reduction potential of the oxidation agent. In contrast, here, the criteria for efficient MABLI radical generation were energetic and geometric for both bidentate ligands and metal acetylacetonates. The strength of this approach is to use stable compounds in 2-components free radical initiating systems and to generate carbon centered radicals. Mechanistic investigations demonstrated the formation of new metal adducts by means of high-resolution mass spectroscopy (HR-ESI-MS) as well as UV-vis spectrometry. As a result of its high radical generating rate, the potential of MABLI was illustrated on the methacrylate free radical polymerization under mild conditions (room temperature, in air) and initiated with a small amount of metal acetylacetonate though it opens new perspectives for acac-like additions in organic chemistry. |
Garra, Patxi; Bonardi, Aude-Heloise; Baralle, Alexandre; Mousawi, Assi Al; Bonardi, Fabien; Dietlin, Celine; Morlet-Savary, Fabrice; Fouassier, Jean-Pierre; Lalevee, Jacques Monitoring photopolymerization reactions through thermal imaging: A unique tool for the real-time follow-up of thick samples, 3D printing, and composites (Article de journal) Journal of Polymer Science Part A-polymer Chemistry, 56 (8), p. 889–899, 2018. @article{Garra2018a, title = {Monitoring photopolymerization reactions through thermal imaging: A unique tool for the real-time follow-up of thick samples, 3D printing, and composites}, author = {Patxi Garra and Aude-Heloise Bonardi and Alexandre Baralle and Assi Al Mousawi and Fabien Bonardi and Celine Dietlin and Fabrice Morlet-Savary and Jean-Pierre Fouassier and Jacques Lalevee}, doi = {10.1002/pola.28965}, year = {2018}, date = {2018-01-01}, journal = {Journal of Polymer Science Part A-polymer Chemistry}, volume = {56}, number = {8}, pages = {889--899}, abstract = {The ever increasing applications of photopolymers from historical thin (<50 mu m) coatings to very deep samples (>1 cm) require the development of robust 4D monitoring strategies able to assess photopolymerization efficiencies (first dimension) as a function of time (second dimension) and position (third and fourth dimensions). Therefore, here, we demonstrated that thermal imaging is a valuable photopolymerization monitoring device showing: (a) very high response times (<1 s); (b) high repeatability of the measurement; (c) strong adaptability of the setup to various conditions (e.g., onto irregular surfaces or inside a real time Fourier transformed infrared spectrometer (RT-FTIR)); (d) extremely deep photopolymerization follow-ups (and subsequent rationalization) with good resolution in time and in space (real-time thermal imaging microscopy experiments); (e) adaptability to applied materials. This monitoring strategy was found particularly robust when taking into account all the heat generating phenomena (i.e., direct heating from the lamp vs. temperature raised due to monomer conversion). As a result, we propose thermal imaging as the next reference monitoring system for the new ranges of thick and/or filled samples (e.g., 3D objects, composites) and/or applied photopolymerizations (e.g., 3D printing) more and more present in the literature. (c) 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2018, 56, 889-899}, keywords = {}, pubstate = {published}, tppubtype = {article} } The ever increasing applications of photopolymers from historical thin (<50 mu m) coatings to very deep samples (>1 cm) require the development of robust 4D monitoring strategies able to assess photopolymerization efficiencies (first dimension) as a function of time (second dimension) and position (third and fourth dimensions). Therefore, here, we demonstrated that thermal imaging is a valuable photopolymerization monitoring device showing: (a) very high response times (<1 s); (b) high repeatability of the measurement; (c) strong adaptability of the setup to various conditions (e.g., onto irregular surfaces or inside a real time Fourier transformed infrared spectrometer (RT-FTIR)); (d) extremely deep photopolymerization follow-ups (and subsequent rationalization) with good resolution in time and in space (real-time thermal imaging microscopy experiments); (e) adaptability to applied materials. This monitoring strategy was found particularly robust when taking into account all the heat generating phenomena (i.e., direct heating from the lamp vs. temperature raised due to monomer conversion). As a result, we propose thermal imaging as the next reference monitoring system for the new ranges of thick and/or filled samples (e.g., 3D objects, composites) and/or applied photopolymerizations (e.g., 3D printing) more and more present in the literature. (c) 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2018, 56, 889-899 |
Zivic, Nicolas; Dumur Frédéric; Xiao Pu; Graff Bernadette; Fouassier Jean Pierre; Gigmes Didier; Lalevée Jacques Zhang Jing; N-[2-(Dimethylamino)ethyl]-1,8-naphthalimide derivatives as photoinitiators under LEDs. (Divers) 2018. @misc{Zhang2018b, title = {N-[2-(Dimethylamino)ethyl]-1,8-naphthalimide derivatives as photoinitiators under LEDs.}, author = {Nicolas; Dumur Frédéric; Xiao Pu; Graff Bernadette; Fouassier Jean Pierre; Gigmes Didier; Lalevée Jacques Zhang Jing; Zivic}, year = {2018}, date = {2018-01-01}, abstract = {Four N-[2-(dimethylamino)ethyl]-1,8-naphthalimide derivatives (ANNs) with different substituents (bromogroup, primary amine, secondary amine, and tertiary amine) in the naphthalimide skeleton have been synthesized and can be used as one-component free radical photoinitiators or incorporated into multi-component photoinitiating systems for free radical or cationic photopolymerization under the irradiation of various LEDs. ANN2 (with secondary amine substituent) or ANN3 (with tertiary amine substituent) alone is capable of initiating the free radical polymerization of acrylates under a LED at 405 nm while ANN0 (with bromo substituent) or ANN1 (with primary amine substituent) does not work. When combined with various additives (e.g. iodonium salt, N -vinylcarbazole, chloro triazine, or tertiary amine), most of the ANN1 –3 based multi-component photoinitiating systems are efficient in free radical photopolymerization at 385 nm, 405 nm, 455 nm, 470 nm and even under a low-intensity polychromatic visible light (from a halogen lamp) with the final conversions being higher than 60% (even more efficient than commercial photoinitiators bisacylphosphine oxide and camphorquinone). In addition, ANN1–3 based photoinitiating systems also exhibit a high efficiency for cationic photopolymerization of epoxides upon diverse LEDs. The ANN2 based photoinitiating system can also be used for the synthesis of interpenetrated polymer networks and adapted for 3D printing. The photochemical mechanisms of the ANN based systems have been comprehensively investigated and discussed in detail}, keywords = {}, pubstate = {published}, tppubtype = {misc} } Four N-[2-(dimethylamino)ethyl]-1,8-naphthalimide derivatives (ANNs) with different substituents (bromogroup, primary amine, secondary amine, and tertiary amine) in the naphthalimide skeleton have been synthesized and can be used as one-component free radical photoinitiators or incorporated into multi-component photoinitiating systems for free radical or cationic photopolymerization under the irradiation of various LEDs. ANN2 (with secondary amine substituent) or ANN3 (with tertiary amine substituent) alone is capable of initiating the free radical polymerization of acrylates under a LED at 405 nm while ANN0 (with bromo substituent) or ANN1 (with primary amine substituent) does not work. When combined with various additives (e.g. iodonium salt, N -vinylcarbazole, chloro triazine, or tertiary amine), most of the ANN1 –3 based multi-component photoinitiating systems are efficient in free radical photopolymerization at 385 nm, 405 nm, 455 nm, 470 nm and even under a low-intensity polychromatic visible light (from a halogen lamp) with the final conversions being higher than 60% (even more efficient than commercial photoinitiators bisacylphosphine oxide and camphorquinone). In addition, ANN1–3 based photoinitiating systems also exhibit a high efficiency for cationic photopolymerization of epoxides upon diverse LEDs. The ANN2 based photoinitiating system can also be used for the synthesis of interpenetrated polymer networks and adapted for 3D printing. The photochemical mechanisms of the ANN based systems have been comprehensively investigated and discussed in detail |
Haddad, Khouloud; Jellali, Salah; Jeguirim, Mejdi; Trabelsi, Aida Ben Hassen; Limousy, Lionel Investigations on phosphorus recovery from aqueous solutions by biochars derived from magnesium-pretreated cypress sawdust (Article de journal) Journal of Environmental Management, 216 , p. IWA, 2018. @article{Haddad2018, title = {Investigations on phosphorus recovery from aqueous solutions by biochars derived from magnesium-pretreated cypress sawdust}, author = { Khouloud Haddad and Salah Jellali and Mejdi Jeguirim and Aida Ben Hassen Trabelsi and Lionel Limousy}, doi = {10.1016/j.jenvman.2017.06.020}, year = {2018}, date = {2018-01-01}, journal = {Journal of Environmental Management}, volume = {216}, pages = {IWA}, abstract = {The ability of biochars, derived from the pyrolysis at 400 degrees C; 500 degrees C and 600 degrees C of pretreated cypress sawdust with 20 wt% magnesium chloride (MgCl2) solutions, in recovering phosphorus from aqueous solutions was investigated under various experimental conditions in batch mode. The experimental results indicated that cypress sawdust pretreatment with MgCl2 induced important modifications of the physical and chemical biochars' properties favoring phosphorus recovery from the used synthetic solutions. Moreover, phosphorus recovery efficiency increased with the increase of the used pyrolysis temperature. Indeed, for an aqueous pH of 5.2 and a phosphorus concentration of 75 mg L-1, the recovered amounts increased from 19.2 mg g(-1) to 33.8 mg g(-1) when the used pyrolysis temperature was raised from 400 degrees C to 600 degrees C. For all the tested biochars, the phosphorus recovery kinetics data were well fitted by the pseudo-second-order model, and the equilibrium state was obtained after 180 min of contact time. Furthermore, the phosphorus recovery data at equilibrium were well described by the Langmuir model with a maximal recovery capacity of 66.7 mg g(-1) for the magnesium pretreated biochar at 600 degrees C. Phosphorus recovery by the used biochars occurred probably through adsorption onto biochars' active sites as well as precipitation with magnesium ions as magnesium phosphates components. All these results suggested that biochars derived from MgCl2 pretreated cypress sawdust could be considered as promising materials for phosphorus recovery from wastewaters for a possible further subsequent use in agriculture as amendments. (C) 2017 Elsevier Ltd. All rights reserved.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The ability of biochars, derived from the pyrolysis at 400 degrees C; 500 degrees C and 600 degrees C of pretreated cypress sawdust with 20 wt% magnesium chloride (MgCl2) solutions, in recovering phosphorus from aqueous solutions was investigated under various experimental conditions in batch mode. The experimental results indicated that cypress sawdust pretreatment with MgCl2 induced important modifications of the physical and chemical biochars' properties favoring phosphorus recovery from the used synthetic solutions. Moreover, phosphorus recovery efficiency increased with the increase of the used pyrolysis temperature. Indeed, for an aqueous pH of 5.2 and a phosphorus concentration of 75 mg L-1, the recovered amounts increased from 19.2 mg g(-1) to 33.8 mg g(-1) when the used pyrolysis temperature was raised from 400 degrees C to 600 degrees C. For all the tested biochars, the phosphorus recovery kinetics data were well fitted by the pseudo-second-order model, and the equilibrium state was obtained after 180 min of contact time. Furthermore, the phosphorus recovery data at equilibrium were well described by the Langmuir model with a maximal recovery capacity of 66.7 mg g(-1) for the magnesium pretreated biochar at 600 degrees C. Phosphorus recovery by the used biochars occurred probably through adsorption onto biochars' active sites as well as precipitation with magnesium ions as magnesium phosphates components. All these results suggested that biochars derived from MgCl2 pretreated cypress sawdust could be considered as promising materials for phosphorus recovery from wastewaters for a possible further subsequent use in agriculture as amendments. (C) 2017 Elsevier Ltd. All rights reserved. |
Mousawi, Assi Al; Arar, Ahmad; Ibrahim-Ouali, Malika; Duval, Sylvain; Dumur, Frederic; Garra, Patxi; Toufaily, Joumana; Hamieh, Tayssir; Graff, Bernadette; Gigmes, Didier; Fouassier, Jean-Pierre; Lalevee, Jacques Carbazole-based compounds as photoinitiators for free radical and cationic polymerization upon near visible light illumination (Article de journal) Photochemical & Photobiological Sciences, 17 (5), p. 578–585, 2018. @article{AlMousawi2018, title = {Carbazole-based compounds as photoinitiators for free radical and cationic polymerization upon near visible light illumination}, author = { Assi Al Mousawi and Ahmad Arar and Malika Ibrahim-Ouali and Sylvain Duval and Frederic Dumur and Patxi Garra and Joumana Toufaily and Tayssir Hamieh and Bernadette Graff and Didier Gigmes and Jean-Pierre Fouassier and Jacques Lalevee}, doi = {10.1039/c7pp00400a}, year = {2018}, date = {2018-01-01}, journal = {Photochemical & Photobiological Sciences}, volume = {17}, number = {5}, pages = {578--585}, abstract = {Six new carbazole based compounds (Ca1-Ca6) are synthesized and proposed as high performance photoinitiators with iodonium salt (iod) and/or an amine (EDB) for both the free radical polymerization (FRP) of acrylates and the cationic polymerization (CP) of epoxides upon near UV and visible light exposure using light emitting diodes (LEDs) @385 nm and @405 nm. Excellent polymerization initiating abilities are found and high final reactive function conversions are acquired. A full picture of the involved photochemical mechanisms is given.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Six new carbazole based compounds (Ca1-Ca6) are synthesized and proposed as high performance photoinitiators with iodonium salt (iod) and/or an amine (EDB) for both the free radical polymerization (FRP) of acrylates and the cationic polymerization (CP) of epoxides upon near UV and visible light exposure using light emitting diodes (LEDs) @385 nm and @405 nm. Excellent polymerization initiating abilities are found and high final reactive function conversions are acquired. A full picture of the involved photochemical mechanisms is given. |
Garra, Patxi; Dumur, Frederic; Nechab, Malek; Morlet-Savary, Fabrice; Dietlin, Celine; Graff, Bernadette; Gigmes, Didier; Fouassier, Jean-Pierre; Lalevee, Jacques Polymer Chemistry, 9 (16), p. 2173–2182, 2018. @article{Garra2018d, title = {Stable copper acetylacetonate-based oxidizing agents in redox (NIR photoactivated) polymerization: an opportunity for the one pot grafting from approach and an example on a 3D printed object}, author = { Patxi Garra and Frederic Dumur and Malek Nechab and Fabrice Morlet-Savary and Celine Dietlin and Bernadette Graff and Didier Gigmes and Jean-Pierre Fouassier and Jacques Lalevee}, doi = {10.1039/c8py00341f}, year = {2018}, date = {2018-01-01}, journal = {Polymer Chemistry}, volume = {9}, number = {16}, pages = {2173--2182}, abstract = {The use of new stable copper acetylacetonates in combination with specific bidentate ligands (e.g. 2dppba) is proposed for redox free radical polymerization (FRP) under mild reaction conditions (under air and at room temperature). These systems show high performances so that they can compete with the well-established reference redox initiating systems based on the amine/benzoylperoxide combination. Remarkably, some of our systems are also highly efficient when excited in the near infrared region (NIR), demonstrating that our redox systems can also be activated by light. Using this strategy, the initial redox free radical polymerization could be converted into a redox photoactivated one. More interestingly, a stable copper methacryloyloxy-ethylacetoacetate (Cu(AAEMA)(2)) bearing a reactive methacrylate function and a copper acetylacetonate moiety could be used to polymerize a first polymer layer onto which a second polymerization could be carried out. Precisely, the second polymerization was initiated by a redox process using mild reaction conditions (at room temperature and under air), different from the process used to form the underlayer. To the best of our knowledge, this re-initiation of polymerization from a pre-polymerized layer by a second polymerization technique is highly original and is of crucial industrial/academic interest as no high energy consumption/harmful wavelengths are required to reinitiate the polymerization. The efficiency of this strategy is illustrated by grafting from a 3D printed object.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The use of new stable copper acetylacetonates in combination with specific bidentate ligands (e.g. 2dppba) is proposed for redox free radical polymerization (FRP) under mild reaction conditions (under air and at room temperature). These systems show high performances so that they can compete with the well-established reference redox initiating systems based on the amine/benzoylperoxide combination. Remarkably, some of our systems are also highly efficient when excited in the near infrared region (NIR), demonstrating that our redox systems can also be activated by light. Using this strategy, the initial redox free radical polymerization could be converted into a redox photoactivated one. More interestingly, a stable copper methacryloyloxy-ethylacetoacetate (Cu(AAEMA)(2)) bearing a reactive methacrylate function and a copper acetylacetonate moiety could be used to polymerize a first polymer layer onto which a second polymerization could be carried out. Precisely, the second polymerization was initiated by a redox process using mild reaction conditions (at room temperature and under air), different from the process used to form the underlayer. To the best of our knowledge, this re-initiation of polymerization from a pre-polymerized layer by a second polymerization technique is highly original and is of crucial industrial/academic interest as no high energy consumption/harmful wavelengths are required to reinitiate the polymerization. The efficiency of this strategy is illustrated by grafting from a 3D printed object. |
Vatankhah-Varnosfaderani, Mohammad; Keith, Andrew N; Cong, Yidan; Liang, Heyi; Rosenthal, Martin; Sztucki, Michael; Clair, Charles; Magonov, Sergei; Ivanov, Dimitri A; Dobrynin, Andrey V; Sheiko, Sergei S Chameleon-like elastomers with molecularly encoded strain-adaptive stiffening and coloration (Article de journal) Science, 359 (6383), p. 1509–+, 2018. @article{Vatankhah-Varnosfaderani2018, title = {Chameleon-like elastomers with molecularly encoded strain-adaptive stiffening and coloration}, author = { Mohammad Vatankhah-Varnosfaderani and Andrew N. Keith and Yidan Cong and Heyi Liang and Martin Rosenthal and Michael Sztucki and Charles Clair and Sergei Magonov and Dimitri A. Ivanov and Andrey V. Dobrynin and Sergei S. Sheiko}, doi = {10.1126/science.aar5308}, year = {2018}, date = {2018-01-01}, journal = {Science}, volume = {359}, number = {6383}, pages = {1509--+}, abstract = {Active camouflage is widely recognized as a soft-tissue feature, and yet the ability to integrate adaptive coloration and tissuelike mechanical properties into synthetic materials remains elusive. We provide a solution to this problem by uniting these functions in moldable elastomers through the self-assembly of linear-bottlebrush-linear triblock copolymers. Microphase separation of the architecturally distinct blocks results in physically cross-linked networks that display vibrant color, extreme softness, and intense strain stiffening on par with that of skin tissue. Each of these functional properties is regulated by the structure of one macromolecule, without the need for chemical cross-linking or additives. These materials remain stable under conditions characteristic of internal bodily environments and under ambient conditions, neither swelling in bodily fluids nor drying when exposed to air.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Active camouflage is widely recognized as a soft-tissue feature, and yet the ability to integrate adaptive coloration and tissuelike mechanical properties into synthetic materials remains elusive. We provide a solution to this problem by uniting these functions in moldable elastomers through the self-assembly of linear-bottlebrush-linear triblock copolymers. Microphase separation of the architecturally distinct blocks results in physically cross-linked networks that display vibrant color, extreme softness, and intense strain stiffening on par with that of skin tissue. Each of these functional properties is regulated by the structure of one macromolecule, without the need for chemical cross-linking or additives. These materials remain stable under conditions characteristic of internal bodily environments and under ambient conditions, neither swelling in bodily fluids nor drying when exposed to air. |
Ryzhikov, A; Daou, J; Nouali, H; Patarin, J; Ouweland, J; Clerick, S; Canck, De E; Voort, Van Der P; Martens, J A Periodic mesoporous organosilicas as porous matrix for heterogeneous lyophobic systems (Article de journal) Microporous Mesoporous Mater., 260 , p. 166, 2018. @article{Ryzhikov2018, title = {Periodic mesoporous organosilicas as porous matrix for heterogeneous lyophobic systems}, author = { A. Ryzhikov and J. Daou and H. Nouali and J. Patarin and J Ouweland and S Clerick and E De Canck and P Van Der Voort and J. A. Martens}, doi = {10.1016/j.micromeso.2017.10.037}, year = {2018}, date = {2018-01-01}, journal = {Microporous Mesoporous Mater.}, volume = {260}, pages = {166}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
Ronchi, Laura; Ryzhikov, Andrey; Nouali, Habiba; Daou, Jean T; Albrecht, Sébastien; Patarin, Joël Extra large pore opening CFI and DON-type zeosils for mechanical energy storage (Article de journal) Microporous Mesoporous Mater., 255 (Supplement C), p. 211–219, 2018, ISSN: 1387-1811. @article{Ronchi2018, title = {Extra large pore opening CFI and DON-type zeosils for mechanical energy storage}, author = { Laura Ronchi and Andrey Ryzhikov and Habiba Nouali and T. Jean Daou and Sébastien Albrecht and Joël Patarin}, url = {http://www.sciencedirect.com/science/article/pii/S1387181117305115}, issn = {1387-1811}, year = {2018}, date = {2018-01-01}, journal = {Microporous Mesoporous Mater.}, volume = {255}, number = {Supplement C}, pages = {211--219}, abstract = {Abstract The energetic performances of pure silica CFI and DON-type zeolites (zeosils) were studied by intrusion-extrusion experiments in water and LiCl aqueous solutions at different concentrations. For both zeosils, characterized by a 1D channel system with 14 MR pore openings, when water is used as nonwetting liquid a perfect reversible spring behavior is observed with an intrusion pressure of 75 and 26 MPa, respectively. The lower value for the DON-type structure is probably due to a larger pore aperture. The intrusion pressures in both cases rise considerably with the LiCl concentration, but the doubling of the salt concentration from 10 to 20 M leads only to a slight increase of the intrusion pressure. The maximal stored energy achieves 14.6 and 6.8 J/g for CFI and DON-type zeosil-based systems, respectively. The zeolite samples were characterized before and after intrusion-extrusion experiments by XRD, SEM, N2 adsorption-desorption, TG and NMR analysis in order to get a better understanding of the influence of these intrusion-extrusion experiments on the CFI and DON-type structures.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Abstract The energetic performances of pure silica CFI and DON-type zeolites (zeosils) were studied by intrusion-extrusion experiments in water and LiCl aqueous solutions at different concentrations. For both zeosils, characterized by a 1D channel system with 14 MR pore openings, when water is used as nonwetting liquid a perfect reversible spring behavior is observed with an intrusion pressure of 75 and 26 MPa, respectively. The lower value for the DON-type structure is probably due to a larger pore aperture. The intrusion pressures in both cases rise considerably with the LiCl concentration, but the doubling of the salt concentration from 10 to 20 M leads only to a slight increase of the intrusion pressure. The maximal stored energy achieves 14.6 and 6.8 J/g for CFI and DON-type zeosil-based systems, respectively. The zeolite samples were characterized before and after intrusion-extrusion experiments by XRD, SEM, N2 adsorption-desorption, TG and NMR analysis in order to get a better understanding of the influence of these intrusion-extrusion experiments on the CFI and DON-type structures. |
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