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Séminaire Chimie ED459

Monolithic porous materials via sol-gel accompanied by phase separation

Prof. Kazuki Nakanishi (Department of Chemistry</I>, Graduate School of Science, Kyoto University, Kyoto, Japan)

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Le Jeudi 22 Septembre 2011 à 13h45
UM2, salle de cours SC-16.01

En complément de ce séminaire, K. Nakanishi donnera trois cours sur le même thème les 19, 21 et 26 septembre après-midi.

1. Résumé du séminaire du jeudi 22 septembre :

Polymerization-induced phase separation in chemically cross-linking systems has been applied to obtain hierarchically porous materials in a broad range of compositions from metal oxides, metalloxane-based hybrids and even to fully organic polymers.

In conventional silica compositions, highly-tenuous macroporous gels composed of fully templated cylindrical mesopores have been synthesized and characterized. Independent control of macro- and mesopores has been achieved. The ultra-high porosity silica monoliths with sub-micron sized skeletons are now evaluated as a next generation monolithic silica column, improving the first generation Chromolith (Merck KGaA). Alkyl- or alkylene-bridged siloxane networks can also be designed to have hierarchical porosity in monolithic forms.

In alkoxy-derived pure titania and zirconia systems, polymeric additives are used to modify the dynamics of phase domains in the course of sol-gel transition. They are useful to separate or concentrating phosphorylated biomolecules. In pure alumina and aluminate systems containing aluminum chloride as a precursor, where propylene oxide was employed to induce homogeneous gelation, macroporous monoliths could be prepared to have varied crystalline phases depending on heat-treatment temperature. Polycrystalline calcium phosphates can also be prepared into porous monolith typically in hydroxyapatite phase.

In pure organic polymer systems, the living radical polymerization of vinyl or acrylate monomers enabled one to obtain monolithic macroporous polymer with dramatically improved homogeneity in macropore structure. As a result of highly interconnected micron-scale skeletons, the mechanical strength has been significantly improved. They can also be converted to monolithic carbon with well-defined macropores.

These macro/mesoporous oxides, hybrids and polymers are being optimized for HPLC columns and other separation/purification devices with improved permeability and efficient accessibility of external molecules to the solid surfaces.

2. Trois cours de niveau Master/Doctorat (en anglais) à l’UM2 par Kazuki Nakanishi :

  • Lundi 19 Septembre 2011 de 15h à 16h30, salle TD-16.01 : Basics of sol-gel chemistry and materials synthesis
  • Mercredi 21 Septembre 2011 de 13h15 à 14h45, salle TD-16.01 : Principles of polymerization-induced phase separation in sol-gels
  • Lundi 26 Septembre 2011 de 15h à 16h30, salle TD-31.12 (Polytech) : Materials with hierarchically controlled pores and their applications

Le Prof. Kazuki Nakanishi est Professeur Invité UM2 (ICGM) / Région Languedoc-Roussillon en septembre 2011.
Contact local ICGM : Dr. Hubert Mutin (équipe CMOS)

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