The Experts below are selected from a list of 318 Experts worldwide ranked by ideXlab platform
Alain Dereux - One of the best experts on this subject based on the ideXlab platform.
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selective surface modification of sio2 tio2 supports with Phosphonic Acids
Chemistry of Materials, 2004Co-Authors: Hubert P Mutin, Vincent Lafond, Aurelian F. Popa, Michel Granier, Laurent Markey, Alain DereuxAbstract:The selective surface modification by Phosphonic Acids of SiO2−TiO2 supports at the micrometer and molecular scale was investigated. Under aqueous conditions, Phosphonic Acids bind to TiO2 and not to SiO2 surfaces. A micropatterned support was prepared by electron beam microlithography and selectivity, of the surface modification was evidenced using scanning Auger electron spectroscopy (SAES). The second support was a mesoporous SiO2−TiO2 mixed oxide (10 mol % Ti) epoxidation catalyst prepared by sol−gel processing. Selectivity was deduced from the decrease of the catalytic activity upon modification and from chemical analysis; bonding modes to the surface were investigated using solid-state 29Si and 31P MAS NMR. The possibility to introduce different organic groups by successive treatments with a Phosphonic acid and a silylating agent was illustrated in the case of the mixed oxide.
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Selective Surface Modification of SiO2−TiO2 Supports with Phosphonic Acids
Chemistry of Materials, 2004Co-Authors: P. Hubert Mutin, Vincent Lafond, Aurelian F. Popa, Michel Granier, Laurent Markey, Alain DereuxAbstract:The selective surface modification by Phosphonic Acids of SiO2−TiO2 supports at the micrometer and molecular scale was investigated. Under aqueous conditions, Phosphonic Acids bind to TiO2 and not to SiO2 surfaces. A micropatterned support was prepared by electron beam microlithography and selectivity, of the surface modification was evidenced using scanning Auger electron spectroscopy (SAES). The second support was a mesoporous SiO2−TiO2 mixed oxide (10 mol % Ti) epoxidation catalyst prepared by sol−gel processing. Selectivity was deduced from the decrease of the catalytic activity upon modification and from chemical analysis; bonding modes to the surface were investigated using solid-state 29Si and 31P MAS NMR. The possibility to introduce different organic groups by successive treatments with a Phosphonic acid and a silylating agent was illustrated in the case of the mixed oxide.
P. Hubert Mutin - One of the best experts on this subject based on the ideXlab platform.
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Tuning Local Nanoparticle Arrangements in TiO2-Polymer Nanocomposites by Grafting of Phosphonic Acids
Macromolecules, 2017Co-Authors: Anne-caroline Genix, P. Hubert Mutin, Celine Schmitt-pauly, Johan G. Alauzun, Thomas Bizien, Julian OberdisseAbstract:The influence of surface-modification of TiO2-nanoparticles with Phosphonic acid molecules on the structure of polymer nanocomposites has been studied by small-angle scattering and transmission electron microscopy. The grafting of Phosphonic Acids was done by phase transfer into chloroform, and polymer nanocomposites have been formulated by solvent casting with two polymers of slightly different hydrophobicity, PMMA and PEMA. By analyzing the shape of the scattering curves around the interparticle correlation peak, and in particular the depth of the correlation hole, information on nearest neighbor correlations between nanoparticles is obtained. While local nanoparticle arrangements are found to be independent of the global particle volume fraction, they are controlled by the degree of hydrophobicity of the alkyl Phosphonic acid grafts with respect to hydrophobicity of matrix. Quantitative analysis of the correlation hole thus evidences the fine-tuning of local nanocomposite structure with Phosphonic Acids.
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Surface modification of alumina-coated silica nanoparticles in aqueous sols with Phosphonic Acids and impact on nanoparticle interactions.
Physical Chemistry Chemical Physics, 2015Co-Authors: Celine Schmitt-pauly, Anne-caroline Genix, Johan G. Alauzun, Julian Oberdisse, Michael Sztucki, P. Hubert MutinAbstract:It is often necessary to tailor nanoparticle (NP) interactions and their compatibility with a polymer matrix by grafting organic groups, but the commonly used silanization route offers little versatility, particularly in water. Herein, alumina-coated silica NPs in aqueous sols have been modified for the first time with low molecular-weight Phosphonic Acids (PAs) bearing organic groups of various hydrophobicities and charges: propyl, pentyl and octyl PAs, and two PAs bearing hydrophilic groups, either a neutraldiethylene glycol (DEPA) or a potentially charged carboxylic acid (CAPA) group. The interactions and aggregation in the sols have been investigated using zeta potential measurements, dynamic light scattering, transmission electron microscopy, and small-angle scattering methods. The surface modification has been studied using FTIR and 31P MAS NMR spectroscopies. Both high grafting density r and high hydrophobicity of the groups on the PAs induced aggregation, whereas suspensions of NPsgrafted by DEPA remained stable up to the highestr . Unexpectedly, CAPA-modified NPs showedaggregation even at low r, suggesting that the carboxylic end group was also grafted to the surface. Surface modification of aqueous sols with PAs allows thus for the grafting of a higher density and a wider variety of organic groups than organosilanes, offering an increased control of the interactions between NPs, which is of interest for designing waterborne nanocomposites.
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Selective Surface Modification of SiO2−TiO2 Supports with Phosphonic Acids
Chemistry of Materials, 2004Co-Authors: P. Hubert Mutin, Vincent Lafond, Aurelian F. Popa, Michel Granier, Laurent Markey, Alain DereuxAbstract:The selective surface modification by Phosphonic Acids of SiO2−TiO2 supports at the micrometer and molecular scale was investigated. Under aqueous conditions, Phosphonic Acids bind to TiO2 and not to SiO2 surfaces. A micropatterned support was prepared by electron beam microlithography and selectivity, of the surface modification was evidenced using scanning Auger electron spectroscopy (SAES). The second support was a mesoporous SiO2−TiO2 mixed oxide (10 mol % Ti) epoxidation catalyst prepared by sol−gel processing. Selectivity was deduced from the decrease of the catalytic activity upon modification and from chemical analysis; bonding modes to the surface were investigated using solid-state 29Si and 31P MAS NMR. The possibility to introduce different organic groups by successive treatments with a Phosphonic acid and a silylating agent was illustrated in the case of the mixed oxide.
Aurelian F. Popa - One of the best experts on this subject based on the ideXlab platform.
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selective surface modification of sio2 tio2 supports with Phosphonic Acids
Chemistry of Materials, 2004Co-Authors: Hubert P Mutin, Vincent Lafond, Aurelian F. Popa, Michel Granier, Laurent Markey, Alain DereuxAbstract:The selective surface modification by Phosphonic Acids of SiO2−TiO2 supports at the micrometer and molecular scale was investigated. Under aqueous conditions, Phosphonic Acids bind to TiO2 and not to SiO2 surfaces. A micropatterned support was prepared by electron beam microlithography and selectivity, of the surface modification was evidenced using scanning Auger electron spectroscopy (SAES). The second support was a mesoporous SiO2−TiO2 mixed oxide (10 mol % Ti) epoxidation catalyst prepared by sol−gel processing. Selectivity was deduced from the decrease of the catalytic activity upon modification and from chemical analysis; bonding modes to the surface were investigated using solid-state 29Si and 31P MAS NMR. The possibility to introduce different organic groups by successive treatments with a Phosphonic acid and a silylating agent was illustrated in the case of the mixed oxide.
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Selective Surface Modification of SiO2−TiO2 Supports with Phosphonic Acids
Chemistry of Materials, 2004Co-Authors: P. Hubert Mutin, Vincent Lafond, Aurelian F. Popa, Michel Granier, Laurent Markey, Alain DereuxAbstract:The selective surface modification by Phosphonic Acids of SiO2−TiO2 supports at the micrometer and molecular scale was investigated. Under aqueous conditions, Phosphonic Acids bind to TiO2 and not to SiO2 surfaces. A micropatterned support was prepared by electron beam microlithography and selectivity, of the surface modification was evidenced using scanning Auger electron spectroscopy (SAES). The second support was a mesoporous SiO2−TiO2 mixed oxide (10 mol % Ti) epoxidation catalyst prepared by sol−gel processing. Selectivity was deduced from the decrease of the catalytic activity upon modification and from chemical analysis; bonding modes to the surface were investigated using solid-state 29Si and 31P MAS NMR. The possibility to introduce different organic groups by successive treatments with a Phosphonic acid and a silylating agent was illustrated in the case of the mixed oxide.
Michel Granier - One of the best experts on this subject based on the ideXlab platform.
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selective surface modification of sio2 tio2 supports with Phosphonic Acids
Chemistry of Materials, 2004Co-Authors: Hubert P Mutin, Vincent Lafond, Aurelian F. Popa, Michel Granier, Laurent Markey, Alain DereuxAbstract:The selective surface modification by Phosphonic Acids of SiO2−TiO2 supports at the micrometer and molecular scale was investigated. Under aqueous conditions, Phosphonic Acids bind to TiO2 and not to SiO2 surfaces. A micropatterned support was prepared by electron beam microlithography and selectivity, of the surface modification was evidenced using scanning Auger electron spectroscopy (SAES). The second support was a mesoporous SiO2−TiO2 mixed oxide (10 mol % Ti) epoxidation catalyst prepared by sol−gel processing. Selectivity was deduced from the decrease of the catalytic activity upon modification and from chemical analysis; bonding modes to the surface were investigated using solid-state 29Si and 31P MAS NMR. The possibility to introduce different organic groups by successive treatments with a Phosphonic acid and a silylating agent was illustrated in the case of the mixed oxide.
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Selective Surface Modification of SiO2−TiO2 Supports with Phosphonic Acids
Chemistry of Materials, 2004Co-Authors: P. Hubert Mutin, Vincent Lafond, Aurelian F. Popa, Michel Granier, Laurent Markey, Alain DereuxAbstract:The selective surface modification by Phosphonic Acids of SiO2−TiO2 supports at the micrometer and molecular scale was investigated. Under aqueous conditions, Phosphonic Acids bind to TiO2 and not to SiO2 surfaces. A micropatterned support was prepared by electron beam microlithography and selectivity, of the surface modification was evidenced using scanning Auger electron spectroscopy (SAES). The second support was a mesoporous SiO2−TiO2 mixed oxide (10 mol % Ti) epoxidation catalyst prepared by sol−gel processing. Selectivity was deduced from the decrease of the catalytic activity upon modification and from chemical analysis; bonding modes to the surface were investigated using solid-state 29Si and 31P MAS NMR. The possibility to introduce different organic groups by successive treatments with a Phosphonic acid and a silylating agent was illustrated in the case of the mixed oxide.
Vincent Lafond - One of the best experts on this subject based on the ideXlab platform.
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selective surface modification of sio2 tio2 supports with Phosphonic Acids
Chemistry of Materials, 2004Co-Authors: Hubert P Mutin, Vincent Lafond, Aurelian F. Popa, Michel Granier, Laurent Markey, Alain DereuxAbstract:The selective surface modification by Phosphonic Acids of SiO2−TiO2 supports at the micrometer and molecular scale was investigated. Under aqueous conditions, Phosphonic Acids bind to TiO2 and not to SiO2 surfaces. A micropatterned support was prepared by electron beam microlithography and selectivity, of the surface modification was evidenced using scanning Auger electron spectroscopy (SAES). The second support was a mesoporous SiO2−TiO2 mixed oxide (10 mol % Ti) epoxidation catalyst prepared by sol−gel processing. Selectivity was deduced from the decrease of the catalytic activity upon modification and from chemical analysis; bonding modes to the surface were investigated using solid-state 29Si and 31P MAS NMR. The possibility to introduce different organic groups by successive treatments with a Phosphonic acid and a silylating agent was illustrated in the case of the mixed oxide.
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Selective Surface Modification of SiO2−TiO2 Supports with Phosphonic Acids
Chemistry of Materials, 2004Co-Authors: P. Hubert Mutin, Vincent Lafond, Aurelian F. Popa, Michel Granier, Laurent Markey, Alain DereuxAbstract:The selective surface modification by Phosphonic Acids of SiO2−TiO2 supports at the micrometer and molecular scale was investigated. Under aqueous conditions, Phosphonic Acids bind to TiO2 and not to SiO2 surfaces. A micropatterned support was prepared by electron beam microlithography and selectivity, of the surface modification was evidenced using scanning Auger electron spectroscopy (SAES). The second support was a mesoporous SiO2−TiO2 mixed oxide (10 mol % Ti) epoxidation catalyst prepared by sol−gel processing. Selectivity was deduced from the decrease of the catalytic activity upon modification and from chemical analysis; bonding modes to the surface were investigated using solid-state 29Si and 31P MAS NMR. The possibility to introduce different organic groups by successive treatments with a Phosphonic acid and a silylating agent was illustrated in the case of the mixed oxide.