Solvent-free synthesis of reactive inorganic precursors for preparation of organic/inorganic hybrid materials

0363826 - ÚMCH 2012 RIV US eng J - Journal Article
Beneš, Hynek - Galy, J. - Gérard, J. F. - Pleštil, Josef - Valette, L.
Solvent-free synthesis of reactive inorganic precursors for preparation of organic/inorganic hybrid materials.
Journal of Sol-Gel Science and Technology. Roč. 59, č. 3 (2011), s. 598-612. ISSN 0928-0707. E-ISSN 1573-4846
Institutional research plan: CEZ:AV0Z40500505
Keywords : sol–gel * alkoxysilane * epoxy
Subject RIV: CD - Macromolecular Chemistry
Impact factor: 1.632, year: 2011

Prehydrolyzed-condensed precursors containing amino or glycido groups were prepared via sol gel process without addition of solvent in any step of their preparation. The influence of the experimental set-up, the functionality and ratio of alkoxysilanes, and type of catalyst, on the structure buildup was studied. In the case of amino precursors, the sol–gel process was carried out at weak basic conditions while in the case of glycido precursors the sol–gel process was catalyzed by acid or neutral pH. The systems with high content of tetraethoxysilane led to the fast gel formation. In weak acid medium tetraethoxysilane formed larger, more condensed species as well as small structures with silanol groups. Strong acidic conditions led to the fast formation of insoluble silica particles in liquid (sol) phase containing monomeric alkoxysilanes.
Permanent Link: http://hdl.handle.net/11104/0199478