Silica−Dimethylsiloxane HybridsNon-Hydrolytic Sol−Gel Synthesis and Characterization by NMR Spectroscopy

Abstract

The non-hydrolytic sol−gel process provides a facile route to silica−dimethylsiloxane (DMS) hybrids starting from silicon(IV) chloride, tetraethoxysilane (TEOS), and hexamethylcyclotrisiloxane, D3. Both the non-hydrolytic sol−gel silica synthesis and ring-opening polymerization of the D3 are initiated simultaneously by the presence of an iron(III) chloride catalyst. Evidence for the structures of these hybrids is presented from the results of solid-state 2D NMR correlation spectroscopy. The siloxane component consists of short D units, which show good compatibility with the silica on a molecular level, probably as a result of copolymerization between Q and D units.