Abstract
Structural changes occurring during the heat treatment of gels that were prepared from binary tetramethoxysilane (TMOS)/diethoxydimethylsilane (DEDMS) mixtures were investigated using infrared spectra. Analysis of the spectral data indicated that the Si-O networks of the heat-treated 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 from the gel network.