The new alkaline sol-gel route presented here allows preparing meso-macrocellular self-standing a... more The new alkaline sol-gel route presented here allows preparing meso-macrocellular self-standing aluminosilicate monoliths that are easy to cast and manipulate and that exhibit open and interconnected macroporosity, high surface area and strong acidic properties. Strong acidity is brought about by the formation of a true mixed oxide. Effectiveness of these catalysts is demonstrated here in the case of bioethanol dehydration, and good performance can be expected in other processes like cracking, isomerization, alkylation reactions, etc.
Novel meso-/macroporous SiO2 monoliths have been reached by applying a nanotectonic pathway withi... more Novel meso-/macroporous SiO2 monoliths have been reached by applying a nanotectonic pathway within a confined geometry, i.e. a non-static air-liquid foam patterning process. Final scaffolds are a very close transcription of the tailored periodic air-liquid foam template while coalesced silica particles are texturing the as-synthesized foam walls. The interconnected nanoparticles and associated void space between adjacent particles allow generating intrinsic mesopores, thereby defining hierarchically organized porous scaffolds. The good control over both the air-liquid foam’s water volume fraction and the bubble size allow a rational tuning of the macropore shape (diameter, Plateau border’s width). In contrast with previous study, closed-cell structures can be reached, while the opal like scaffold structure is maintained with thermal treatment, avoiding thus strong shrinkage associated to the sintering effect.
Titanium dioxide macro-cellular monolith-type materials have been obtained with emphases toward c... more Titanium dioxide macro-cellular monolith-type materials have been obtained with emphases toward controlling porosity at the meso- and macroscopic length scales, leading thus to hierarchically organized porous architectures. First, at the microscopic length scale, either monophasic Anatase, biphasic Anatase-Rutile or monophasic Rutile allotropic forms are generated by varying the applied thermal treatment. At the meso- and/or nanoscopic length scales either lyotropic templates or latex colloids have been used to promote meso- or super-mesoporosity. Particularly, a Pluronic copolymer P-123 combined with cationic surfactant (TTAB) induces vermicular-like mesoporosity associated with a specific surface area around 450 m2·g-1. At the macroscopic length scale a non-static air-liquid foam strategy allows a strong control over the open-cell morphologies.
ABSTRACT Ces microcapsules sont constituées d'un coeur de cire, c'est-à-dire d&am... more ABSTRACT Ces microcapsules sont constituées d'un coeur de cire, c'est-à-dire d'huile cristallisée, entouré d'une écorce de silice obtenue par la minéralisation de l'interface eau-huile. En chauffant, l'huile devient liquide et ce changement d'état est accompagné d'une expansion volumique qui provoque la rupture de l'écorce rigide et cassante, permettant la libération de l'huile. Ces capsules, dont la rupture est déclenchée par un stimulus extérieur font partie de la classe des matériaux dits « intelligents ». La température de rupture de la coque, et en conséquence, de libération du contenu, est déterminée par la température de fusion de l'huile ; la taille des capsules est quant à elle, fixée par la formulation d'émulsions dites de Pickering, c'est-à-dire stabilisées par des particules colloïdales.
L'invention est relative a un procede de fabrication de fibres macroscopiques de dioxyde de t... more L'invention est relative a un procede de fabrication de fibres macroscopiques de dioxyde de titane (TiO2) par extrusion en continu en flux unidirectionnel, aux fibres macroscopiques de Ti02 susceptibles d'etre obtenues par un tel procede, a l'utilisation de ces fibres en photocatalyse heterogene pour la decontamination en polluants organiques de milieux gazeux ainsi qu'a un procede de decontamination de milieux gazeux, notamment de l'air, mettant en œuvre de telles fibres.
The precipitation of calcium oxalate monohydrate (COM) at phospholipid monolayers has been observ... more The precipitation of calcium oxalate monohydrate (COM) at phospholipid monolayers has been observed in-situ by Brewster angle microscopy (BAM). A monolayer of 1,2-dipalmitoylsn-glycero-3-phosphocholine (DPPC) compressed to a LC state over a calcium oxalate subphase shows the growth of COM as very bright spots. The identity of COM was confirmed in a transferred film by scanning electron microscopy. BAM can also be used to determine where COM precipitates when the monolayer has two phases at equilibrium. Monolayers of DPPC and 1,2-dipalmitoyl-sn-glycero-3-[phospho-rac-(1-glycerol)] (DPPG) crystallize COM at phase boundaries. In addition, phase separated binary phospholipid mixtures of DPPC and 1,2-dimiristoyl-sn-glycero-3-phosphocholine (DMPC) have been prepared and monitored by BAM. The crystal growth in this case is confined to domains of DPPC due to its ability to form a liquid condensed phase.
The new alkaline sol-gel route presented here allows preparing meso-macrocellular self-standing a... more The new alkaline sol-gel route presented here allows preparing meso-macrocellular self-standing aluminosilicate monoliths that are easy to cast and manipulate and that exhibit open and interconnected macroporosity, high surface area and strong acidic properties. Strong acidity is brought about by the formation of a true mixed oxide. Effectiveness of these catalysts is demonstrated here in the case of bioethanol dehydration, and good performance can be expected in other processes like cracking, isomerization, alkylation reactions, etc.
Novel meso-/macroporous SiO2 monoliths have been reached by applying a nanotectonic pathway withi... more Novel meso-/macroporous SiO2 monoliths have been reached by applying a nanotectonic pathway within a confined geometry, i.e. a non-static air-liquid foam patterning process. Final scaffolds are a very close transcription of the tailored periodic air-liquid foam template while coalesced silica particles are texturing the as-synthesized foam walls. The interconnected nanoparticles and associated void space between adjacent particles allow generating intrinsic mesopores, thereby defining hierarchically organized porous scaffolds. The good control over both the air-liquid foam’s water volume fraction and the bubble size allow a rational tuning of the macropore shape (diameter, Plateau border’s width). In contrast with previous study, closed-cell structures can be reached, while the opal like scaffold structure is maintained with thermal treatment, avoiding thus strong shrinkage associated to the sintering effect.
Titanium dioxide macro-cellular monolith-type materials have been obtained with emphases toward c... more Titanium dioxide macro-cellular monolith-type materials have been obtained with emphases toward controlling porosity at the meso- and macroscopic length scales, leading thus to hierarchically organized porous architectures. First, at the microscopic length scale, either monophasic Anatase, biphasic Anatase-Rutile or monophasic Rutile allotropic forms are generated by varying the applied thermal treatment. At the meso- and/or nanoscopic length scales either lyotropic templates or latex colloids have been used to promote meso- or super-mesoporosity. Particularly, a Pluronic copolymer P-123 combined with cationic surfactant (TTAB) induces vermicular-like mesoporosity associated with a specific surface area around 450 m2·g-1. At the macroscopic length scale a non-static air-liquid foam strategy allows a strong control over the open-cell morphologies.
ABSTRACT Ces microcapsules sont constituées d'un coeur de cire, c'est-à-dire d&am... more ABSTRACT Ces microcapsules sont constituées d'un coeur de cire, c'est-à-dire d'huile cristallisée, entouré d'une écorce de silice obtenue par la minéralisation de l'interface eau-huile. En chauffant, l'huile devient liquide et ce changement d'état est accompagné d'une expansion volumique qui provoque la rupture de l'écorce rigide et cassante, permettant la libération de l'huile. Ces capsules, dont la rupture est déclenchée par un stimulus extérieur font partie de la classe des matériaux dits « intelligents ». La température de rupture de la coque, et en conséquence, de libération du contenu, est déterminée par la température de fusion de l'huile ; la taille des capsules est quant à elle, fixée par la formulation d'émulsions dites de Pickering, c'est-à-dire stabilisées par des particules colloïdales.
L'invention est relative a un procede de fabrication de fibres macroscopiques de dioxyde de t... more L'invention est relative a un procede de fabrication de fibres macroscopiques de dioxyde de titane (TiO2) par extrusion en continu en flux unidirectionnel, aux fibres macroscopiques de Ti02 susceptibles d'etre obtenues par un tel procede, a l'utilisation de ces fibres en photocatalyse heterogene pour la decontamination en polluants organiques de milieux gazeux ainsi qu'a un procede de decontamination de milieux gazeux, notamment de l'air, mettant en œuvre de telles fibres.
The precipitation of calcium oxalate monohydrate (COM) at phospholipid monolayers has been observ... more The precipitation of calcium oxalate monohydrate (COM) at phospholipid monolayers has been observed in-situ by Brewster angle microscopy (BAM). A monolayer of 1,2-dipalmitoylsn-glycero-3-phosphocholine (DPPC) compressed to a LC state over a calcium oxalate subphase shows the growth of COM as very bright spots. The identity of COM was confirmed in a transferred film by scanning electron microscopy. BAM can also be used to determine where COM precipitates when the monolayer has two phases at equilibrium. Monolayers of DPPC and 1,2-dipalmitoyl-sn-glycero-3-[phospho-rac-(1-glycerol)] (DPPG) crystallize COM at phase boundaries. In addition, phase separated binary phospholipid mixtures of DPPC and 1,2-dimiristoyl-sn-glycero-3-phosphocholine (DMPC) have been prepared and monitored by BAM. The crystal growth in this case is confined to domains of DPPC due to its ability to form a liquid condensed phase.
Uploads
Papers