Extrusion-based <i>Integrative Chemistry</i>: Generation and applications of inorganic fibers

International audienceIn this review we depict how fibers can be obtained by combining sol-gel and polymer chemistry with extrusion processes acting as an external shaping mode. Thanks to this Integrative Chemistry-based synthetic path, it was possible to organize nano-building blocks such as V2O5 ribbons and ZnO nanorods on a greater length scale yielding highly anisotropic fibers. It has been demonstrated that when aligning a whole population of nano-building block objects along a single main axis, collective properties were obtained, thereby enhancing their sensing, mechanical or photonic properties. This method can be extended toward fiber morphogenesis by using isotropic nanoparticles such as TiO2, and can be scaled-up toward the one-step generation of several hundred meter long fibers with both high surface to volume ratio and high surface roughness. Specifically, when addressing photocatalytic-based VOC pollutant degradation, these TiO2 fibers appear to be outstanding candidates regarding both pollutant degradation and associated mineralization(production of water and carbon dioxide)

Integrative chemistry for the synthesis of advanced functional materials

Une porosité hiérarchisée au sein de mousses solides permet la combinaison des avantages offerts par différentes échelles de structuration : les macropores offrent un grand volume poreux et une diffusion facilitée des réactifs, tandis que mésopores et micropores permettent confinement et grande surface spécifique. La chimie intégrative, en associant la matière molle et la chimie douce, dispose d’une variété de voies de synthèse pour obtenir de tels matériaux. Nous avons ainsi utilisé des émulsions et des tensioactifs comme empreintes pour la chimie sol-gel afin d’obtenir des mousses de silice présentant une porosité hiérarchisée. Elles ont ensuite été employées comme empreintes dures pour synthétiser des mousses de carbone, utilisées comme électrodes de batteries lithium-soufre présentant de grandes capacités. Nous avons ensuite étudié l’effet sur leurs performances de nanoparticules métalliques. Ces mousses ont également été testées pour le stockage de l’hydrogène, et nous avons montré un cyclage avec LiBH4 en présence de nanoparticules métalliques. Enfin, les mousses de silices ont été étudiées en tant que support pour la croissance bactérienne. En effet, lorsque des bactéries croissent dans un milieu confiné, leur cinétique de croissance et leur concentration finale peuvent être totalement différentes de ce qui est observé dans des cultures classiques, ce qui a un grand intérêt dans des domaines comme la biocatalyse.Hierarchical porosity in solid foams allows the combination of the advantages offered by the different scales of structuration : macropores allow high porous volume and easy diffusion of reagents, while mesopores and micropores allow confinement and high specific surface areas. Integrative chemistry, associating soft matter and soft chemistry, offers a variety of synthetic pathways to generate such materials. We used emulsions and surfactants to template sol-gel chemistry in order to obtain silica foams bearing hierarchical porosity. These silica foams were employed as hard templates to synthesize carbon foams, used as electrodes in lithium-sulfur batteries bearing high capacities. We then explored the impact on performances of loading them with metallic nanoparticles. We also studied the potential of those carbon foams for hydrogen storage, and we obtained cycling capabilities with LiBH4 after loading them with metallic nanoparticles. Finally, the silica foams were used as a support for bacterial growth. Indeed, when bacteria grow in a confined medium, the kinetics of growth and their final concentration can be totally different than what is observed in classical cultures, which is of high interest for applications such as biocatalysis

Integrative chemistry for the synthesis of advanced functional materials

Une porosité hiérarchisée au sein de mousses solides permet la combinaison des avantages offerts par différentes échelles de structuration : les macropores offrent un grand volume poreux et une diffusion facilitée des réactifs, tandis que mésopores et micropores permettent confinement et grande surface spécifique. La chimie intégrative, en associant la matière molle et la chimie douce, dispose d’une variété de voies de synthèse pour obtenir de tels matériaux. Nous avons ainsi utilisé des émulsions et des tensioactifs comme empreintes pour la chimie sol-gel afin d’obtenir des mousses de silice présentant une porosité hiérarchisée. Elles ont ensuite été employées comme empreintes dures pour synthétiser des mousses de carbone, utilisées comme électrodes de batteries lithium-soufre présentant de grandes capacités. Nous avons ensuite étudié l’effet sur leurs performances de nanoparticules métalliques. Ces mousses ont également été testées pour le stockage de l’hydrogène, et nous avons montré un cyclage avec LiBH4 en présence de nanoparticules métalliques. Enfin, les mousses de silices ont été étudiées en tant que support pour la croissance bactérienne. En effet, lorsque des bactéries croissent dans un milieu confiné, leur cinétique de croissance et leur concentration finale peuvent être totalement différentes de ce qui est observé dans des cultures classiques, ce qui a un grand intérêt dans des domaines comme la biocatalyse.Hierarchical porosity in solid foams allows the combination of the advantages offered by the different scales of structuration : macropores allow high porous volume and easy diffusion of reagents, while mesopores and micropores allow confinement and high specific surface areas. Integrative chemistry, associating soft matter and soft chemistry, offers a variety of synthetic pathways to generate such materials. We used emulsions and surfactants to template sol-gel chemistry in order to obtain silica foams bearing hierarchical porosity. These silica foams were employed as hard templates to synthesize carbon foams, used as electrodes in lithium-sulfur batteries bearing high capacities. We then explored the impact on performances of loading them with metallic nanoparticles. We also studied the potential of those carbon foams for hydrogen storage, and we obtained cycling capabilities with LiBH4 after loading them with metallic nanoparticles. Finally, the silica foams were used as a support for bacterial growth. Indeed, when bacteria grow in a confined medium, the kinetics of growth and their final concentration can be totally different than what is observed in classical cultures, which is of high interest for applications such as biocatalysis

Integrative chemistry: Positioning chemical reactors within the geometric space as a tool for the design of advanced functional materials

AbstractChemical sciences are on continuous evolution offering more and more complex synthetic strategies that rely on emerging inter- and trans-disciplinary vocation. In this tutorial review, we demonstrate how integrative chemistry, through combining soft matter and soft chemistry, allows positioning chemical reactors within the geometric space. Therefore, we focus the examples on biliquid foam oil/water interfaces and sol–gel chemistry. In this view we distinguish between diluted and concentrated emulsions, acting respectively as discrete chemical reactors and percolated ones. Along the manuscript, non-exhaustive morphosyntheses of advanced functional materials are proposed when dedicated either to heterogeneous biocatalysts, energy conversion systems and thermo-stimulated delivery of encapsulated substances

Extrusion-based Integrative Chemistry: Generation and applications of inorganic fibers

AbstractIn this review we depict how fibers can be obtained by combining sol-gel and polymer chemistry with extrusion processes acting as an external shaping mode. Thanks to this Integrative Chemistry-based synthetic path, it was possible to organize nano-building blocks such as V2O5 ribbons and ZnO nanorods on a greater length scale yielding highly anisotropic fibers. It has been demonstrated that when aligning a whole population of nano-building block objects along a single main axis, collective properties were obtained, thereby enhancing their sensing, mechanical or photonic properties. This method can be extended toward fiber morphogenesis by using isotropic nanoparticles such as TiO2, and can be scaled-up toward the one-step generation of several hundred meter long fibers with both high surface to volume ratio and high surface roughness. Specifically, when addressing photocatalytic-based VOC pollutant degradation, these TiO2 fibers appear to be outstanding candidates regarding both pollutant degradation and associated mineralization (production of water and carbon dioxide)

A multiscale study of bacterial proliferation modes within novel E. coli@Si(HIPE) hybrid macrocellular living foams

International audienceFor the first time the study at various length scales of E. coli proliferation modes within Si(HIPE) inorganic macrocellular foams is proposed. Both qualitatively and semi-quantitatively, the bacterial proliferation within the foam is not homogeneous and is directly linked to the Si(HIPE)'s macroscopic cells random distribution. When inoculated in a nutrients loaded Si(HIPE), the bacterial growth is enhanced within the Si(HIPE) matrices compared to the surrounding LB media. The bacteria growth kinetics tends to be faster and the concentration at saturation is roughly 100% times higher. In the case of a Si(HIPE) host free of nutrients, the bacterial motion is occurring as an infiltration wave, the peak of this propagation wave moving at a constant speed of 88 µm h-1 , while bacterial concentrations within the Si(HIPE) reach levels far above the ones reached with the presence of nutrients, suggesting a real synergetic relation between the bacterial colony guests and the Si(HIPE) host. When a nutrients reservoir is present at the opposite position from which bacteria were inoculated, the bacterial proliferation is associated to a coalescence process between the growing colonies that were rapidly established within the first hours. When the Si(HIPE) is fully colonized we found out a specific distance between adjacent colonies of 5 to 15 µm in good correspondence with the repartition of the wall to wall distances of the Si(HIPE)'s macroscopic cells, meaning that the bacterial repartition once the colonization occurred is optimum. These results show that Si(HIPE) foams represent outstanding candidates for strengthened bacterial proliferation without the motion restriction imposed by conventional silica gels