INFRARED SPECTRAL STRUCTURAL INVESTIGATION OF THE HEAT-TREATMENT OF TETRAMETHOXYSILANE DIETHOXYDIMETHYLSILANE-DERIVED GELS

Structural changes occurring during the heat treatment of gels that we re prepared from binary tetramethoxysilane (TMOS)/diethoxydimethylsila ne (DEDMS) mixtures were investigated using infrared spectra. Analysis of the spectral data indicated that the Si-O networks of the heat-tre ated gels increased their connectivity with increased dehydration due to increased treatment temperature or time. Four- and three-membered ( Si-O)n rings were noted for appropriate heat-treated gel compositions. At higher heat-treatment temperatures, methyl groups were removed fro m the gel network.