Cyril Vaulot - Academia.edu (original) (raw)
Papers by Cyril Vaulot
Materials, Dec 16, 2022
This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY
HAL (Le Centre pour la Communication Scientifique Directe), May 18, 2015
National audienc
Materials Chemistry Frontiers
In this work, the LTA-5A zeolite and Al2O3 are used as fillers in composites prepared by photopol... more In this work, the LTA-5A zeolite and Al2O3 are used as fillers in composites prepared by photopolymerization.
Industrial & Engineering Chemistry Research
Materials
Photo-catalysts based on titanium dioxide, and modified with highly dispersed metallic nanopartic... more Photo-catalysts based on titanium dioxide, and modified with highly dispersed metallic nanoparticles of Au, Ag, Pd and Pt, either mono- or bi-metallic, have been analyzed by multiple characterization techniques, including XRD, XPS, SEM, EDX, UV-Vis and N2 adsorption/desorption. Mono-metallic photo-catalysts were prepared by wet impregnation, while bi-metallic photocatalysts were obtained via deposition-precipitation (DP). The relationship between the physico-chemical properties and the catalyst’s behavior for various photo-synthetic processes, such as carbon dioxide photo-reduction to liquid products and glucose photo-reforming to hydrogen have been investigated. Among the tested materials, the catalysts containing platinum alone (i.e., 0.1 mol% Pt/TiO2) or bi-metallic gold-containing materials (e.g., 1 wt% (AuxAgy)/TiO2 and 1 wt% (AuxPtz)/TiO2) showed the highest activity, presenting the best results in terms of productivity and conversion for both applications. The textural, struc...
Solar Energy Materials and Solar Cells, 2022
Fuel Processing Technology, 2022
Energy Advances, 2022
Oxygen physi- and chemisorption were used to determine the hard carbon total specific and active ... more Oxygen physi- and chemisorption were used to determine the hard carbon total specific and active surface areas, respectively, which have been correlated with irreversible capacity loss during the first charge/discharge...
Materials, 2022
The present study investigates the potential of waste tires to produce a valuable adsorbent mater... more The present study investigates the potential of waste tires to produce a valuable adsorbent material for application in wastewater treatment. In the first stage, the pyrolysis of ground rubber tire was explored using non-isothermal and isothermal thermogravimetric analysis experiments. The effect of operating parameters, such as heating rate and pyrolysis temperature, on the pyrolysis product yields was considered. The slow pyrolysis of ground rubber tire was taken up in a large-scale fixed-bed reactor for enhanced char recovery. Four pyrolysis temperatures were selected by thermogravimetric data. The product yields were strongly influenced by the pyrolysis temperature; at higher temperatures, the formation of more gases and liquid was favored, while at lower pyrolysis temperatures, more char (solid fraction) was formed. The produced chars were characterized in terms of mineral composition, textural properties, proximate analysis, and structural properties to identify the relationsh...
Renewable and Sustainable Energy Reviews, 2022
The hydrolytic degradation of fully cured polyester-urethane networks polymerized in the presence... more The hydrolytic degradation of fully cured polyester-urethane networks polymerized in the presence of several weight ratios of triacetin was monitored by the residual concentration in elastically active chains obtained from modulus and equilibrium solvent swelling measurements. The presence of triacetin does not change the water uptake but induces a lower rate of degradation. Comparisons were performed with networks in which triacetin was removed before ageing, and with networks in which polyester-urethane was first polymerized and then impregnated by triacetin. Data suggest that the presence of triacetin during polymerization induces the presence of elastically inactive chains such as dangling chains, loops… the hydrolysis of which does not change the elastic properties of the network. This explanation was checked from relaxation measurements by n.m.r and d.m.a, and by the analysis of the soluble fraction generated by hydrolysis.
Confronte a la comprehension des mecanismes de formation de materiaux nanocomposites par intercal... more Confronte a la comprehension des mecanismes de formation de materiaux nanocomposites par intercalation ou exfoliation d’argile dans des matrices polymeres, ce travail s’est inscrit dans une approche multidisciplinaire. Pour en controler les proprietes, la montmorillonite a ete synthetisee selon un procede hydrothermal et modifiee organiquement par un tensioactif cationique alkylammonium (C18TMABr) pour accroitre la distance interfoliaire. L’etude des proprietes physico-chimiques (CGI, extraction) et structurales (SAXS, WAXS, DSC) nous a mene a la differenciation de deux etats d'adsorption references thermodynamiquement et structuralement et semblable quantitativement, l’un correspondant a l’echange cationique pur, l’autre a la physisorption du tensioactif. Ce dernier s’est revele propice a un agrandissement plus consequent de l’espace interfoliaire et a une organisation cristalline des molecules organiques dont la fusion est mise en evidence par DRX et DSC. Les etudes des compor...
European Polymer Journal, 2021
Polymer Chemistry, 2019
Diblock copolymer nanoparticles were prepared by photomediated polymerization-induced self-assemb... more Diblock copolymer nanoparticles were prepared by photomediated polymerization-induced self-assembly (“photo-PISA”) in dispersion.
ACS Omega, 2019
Base catalyst and oxidant are usually necessary to promote the polymerization of poly(disulfide) ... more Base catalyst and oxidant are usually necessary to promote the polymerization of poly(disulfide) oligomers through oxidative coupling of the terminal SH groups into S− S bonds. In this study, we prove that self-polymerization of bifunctional (disulfide) oligomer films can take place in a matter of minutes under UVC irradiation (254 nm, 10.5 mW cm −2). The resulting insoluble polymer is characterized using solid-state NMR, 1 H T 2 NMR relaxation measurements, thermal analysis, and Fourier-transform infrared spectroscopy and proves to have similar composition as a model poly(disulfide) prepared under oxidative conditions, but distinct physical properties. These differences are explained by a change in polymer architecture due to a higher ratio of cyclization relative to linear polymerization. Homolytic photocleavage of internal S−S bonds creates thiyl groups close to each other, driving an increased kinetic feasibility for the cyclization reaction by radical coupling. The subsequent formation of mechanically interlocked macrocycles (polycatenane network) is proposed to account for film properties analogous to those of a cross-linked polymer.
Food Structure, 2017
We studied the impact of temperature of cooking on meat microstructure. The cooking temperature w... more We studied the impact of temperature of cooking on meat microstructure. The cooking temperature was verified by calorimetry, showing the disappearance of endothermic peaks when cooking temperature was increased. These observations correspond to the denaturation of different protein fractions at specific temperatures. 1H-low field NMR and neutron tomography were used to further understand the relationship between the observed protein denaturation and changes in meat microstructure after heating. Hahn’s echo and solid echo NMR sequences were applied to observe fast relaxation time corresponding to rigid protons. These protons were found to be associated with pools of protons with a strong interaction with the meat matrix. Their relaxation times (T2) are of order of 500–900 μs (for Hahn’s echo sequence) and 10 μs (for solid echo’s sequence). These protons become more rigid upon increasing the temperature. 3D neutron tomography analysis demonstrated the defects created by the contraction of meat fibers and allowed measurement of their volume, which increase for the highest cooking degrees. This analysis allowed classification of the defects as a function of their position (surface or interior) and size (threshold 0.075 % v/v). Our results demonstrate that large defects increase increasing cooking temperature and are located at the surface of the meat slice.
Materials, Dec 16, 2022
This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY
HAL (Le Centre pour la Communication Scientifique Directe), May 18, 2015
National audienc
Materials Chemistry Frontiers
In this work, the LTA-5A zeolite and Al2O3 are used as fillers in composites prepared by photopol... more In this work, the LTA-5A zeolite and Al2O3 are used as fillers in composites prepared by photopolymerization.
Industrial & Engineering Chemistry Research
Materials
Photo-catalysts based on titanium dioxide, and modified with highly dispersed metallic nanopartic... more Photo-catalysts based on titanium dioxide, and modified with highly dispersed metallic nanoparticles of Au, Ag, Pd and Pt, either mono- or bi-metallic, have been analyzed by multiple characterization techniques, including XRD, XPS, SEM, EDX, UV-Vis and N2 adsorption/desorption. Mono-metallic photo-catalysts were prepared by wet impregnation, while bi-metallic photocatalysts were obtained via deposition-precipitation (DP). The relationship between the physico-chemical properties and the catalyst’s behavior for various photo-synthetic processes, such as carbon dioxide photo-reduction to liquid products and glucose photo-reforming to hydrogen have been investigated. Among the tested materials, the catalysts containing platinum alone (i.e., 0.1 mol% Pt/TiO2) or bi-metallic gold-containing materials (e.g., 1 wt% (AuxAgy)/TiO2 and 1 wt% (AuxPtz)/TiO2) showed the highest activity, presenting the best results in terms of productivity and conversion for both applications. The textural, struc...
Solar Energy Materials and Solar Cells, 2022
Fuel Processing Technology, 2022
Energy Advances, 2022
Oxygen physi- and chemisorption were used to determine the hard carbon total specific and active ... more Oxygen physi- and chemisorption were used to determine the hard carbon total specific and active surface areas, respectively, which have been correlated with irreversible capacity loss during the first charge/discharge...
Materials, 2022
The present study investigates the potential of waste tires to produce a valuable adsorbent mater... more The present study investigates the potential of waste tires to produce a valuable adsorbent material for application in wastewater treatment. In the first stage, the pyrolysis of ground rubber tire was explored using non-isothermal and isothermal thermogravimetric analysis experiments. The effect of operating parameters, such as heating rate and pyrolysis temperature, on the pyrolysis product yields was considered. The slow pyrolysis of ground rubber tire was taken up in a large-scale fixed-bed reactor for enhanced char recovery. Four pyrolysis temperatures were selected by thermogravimetric data. The product yields were strongly influenced by the pyrolysis temperature; at higher temperatures, the formation of more gases and liquid was favored, while at lower pyrolysis temperatures, more char (solid fraction) was formed. The produced chars were characterized in terms of mineral composition, textural properties, proximate analysis, and structural properties to identify the relationsh...
Renewable and Sustainable Energy Reviews, 2022
The hydrolytic degradation of fully cured polyester-urethane networks polymerized in the presence... more The hydrolytic degradation of fully cured polyester-urethane networks polymerized in the presence of several weight ratios of triacetin was monitored by the residual concentration in elastically active chains obtained from modulus and equilibrium solvent swelling measurements. The presence of triacetin does not change the water uptake but induces a lower rate of degradation. Comparisons were performed with networks in which triacetin was removed before ageing, and with networks in which polyester-urethane was first polymerized and then impregnated by triacetin. Data suggest that the presence of triacetin during polymerization induces the presence of elastically inactive chains such as dangling chains, loops… the hydrolysis of which does not change the elastic properties of the network. This explanation was checked from relaxation measurements by n.m.r and d.m.a, and by the analysis of the soluble fraction generated by hydrolysis.
Confronte a la comprehension des mecanismes de formation de materiaux nanocomposites par intercal... more Confronte a la comprehension des mecanismes de formation de materiaux nanocomposites par intercalation ou exfoliation d’argile dans des matrices polymeres, ce travail s’est inscrit dans une approche multidisciplinaire. Pour en controler les proprietes, la montmorillonite a ete synthetisee selon un procede hydrothermal et modifiee organiquement par un tensioactif cationique alkylammonium (C18TMABr) pour accroitre la distance interfoliaire. L’etude des proprietes physico-chimiques (CGI, extraction) et structurales (SAXS, WAXS, DSC) nous a mene a la differenciation de deux etats d'adsorption references thermodynamiquement et structuralement et semblable quantitativement, l’un correspondant a l’echange cationique pur, l’autre a la physisorption du tensioactif. Ce dernier s’est revele propice a un agrandissement plus consequent de l’espace interfoliaire et a une organisation cristalline des molecules organiques dont la fusion est mise en evidence par DRX et DSC. Les etudes des compor...
European Polymer Journal, 2021
Polymer Chemistry, 2019
Diblock copolymer nanoparticles were prepared by photomediated polymerization-induced self-assemb... more Diblock copolymer nanoparticles were prepared by photomediated polymerization-induced self-assembly (“photo-PISA”) in dispersion.
ACS Omega, 2019
Base catalyst and oxidant are usually necessary to promote the polymerization of poly(disulfide) ... more Base catalyst and oxidant are usually necessary to promote the polymerization of poly(disulfide) oligomers through oxidative coupling of the terminal SH groups into S− S bonds. In this study, we prove that self-polymerization of bifunctional (disulfide) oligomer films can take place in a matter of minutes under UVC irradiation (254 nm, 10.5 mW cm −2). The resulting insoluble polymer is characterized using solid-state NMR, 1 H T 2 NMR relaxation measurements, thermal analysis, and Fourier-transform infrared spectroscopy and proves to have similar composition as a model poly(disulfide) prepared under oxidative conditions, but distinct physical properties. These differences are explained by a change in polymer architecture due to a higher ratio of cyclization relative to linear polymerization. Homolytic photocleavage of internal S−S bonds creates thiyl groups close to each other, driving an increased kinetic feasibility for the cyclization reaction by radical coupling. The subsequent formation of mechanically interlocked macrocycles (polycatenane network) is proposed to account for film properties analogous to those of a cross-linked polymer.
Food Structure, 2017
We studied the impact of temperature of cooking on meat microstructure. The cooking temperature w... more We studied the impact of temperature of cooking on meat microstructure. The cooking temperature was verified by calorimetry, showing the disappearance of endothermic peaks when cooking temperature was increased. These observations correspond to the denaturation of different protein fractions at specific temperatures. 1H-low field NMR and neutron tomography were used to further understand the relationship between the observed protein denaturation and changes in meat microstructure after heating. Hahn’s echo and solid echo NMR sequences were applied to observe fast relaxation time corresponding to rigid protons. These protons were found to be associated with pools of protons with a strong interaction with the meat matrix. Their relaxation times (T2) are of order of 500–900 μs (for Hahn’s echo sequence) and 10 μs (for solid echo’s sequence). These protons become more rigid upon increasing the temperature. 3D neutron tomography analysis demonstrated the defects created by the contraction of meat fibers and allowed measurement of their volume, which increase for the highest cooking degrees. This analysis allowed classification of the defects as a function of their position (surface or interior) and size (threshold 0.075 % v/v). Our results demonstrate that large defects increase increasing cooking temperature and are located at the surface of the meat slice.