Microporous nanocomposite material synthesized by sol-gel processing in the presence of cyclodextrins

摘要

It is shown that the addition of precursor, tetrakis(2-hydroxyethyl) orthosilicate, that is absolutely soluble in water to a solution of cyclodextrins (CDs) leads to the formation of a hydrogel as a result of sol-gel processes. The synthesis is performed with neither a catalyst nor heating under the conditions that are inapplicable for traditionally employed precursors (tetraethoxy- and tetramethoxysilanes). The occurrence of sol-gel processes is due to the catalytic action of CDs. At the same time, their molecules act as matrix for precipitating polysilicic acids. As a result of hydrogel calcination, xerogels were prepared with micropores and microparticles dimensions of which were determined by the sizes of CD molecules.