Abstract
Organosiloxane (RnSiO(4-n)/2) gels can be prepared from organoalkoxysilanes using the sol-gel process. In general, however, formation of uniform networks from these precursors is strongly inhibited due to cyclization reactions. In addition, phase separation of hydrophobic condensates from polar solvent leads to inhomogeneous gels in these systems. A careful control of the hydrolysis and polycondensation reactions is therefore required to obtain a monolithic gel with desired properties. We have been trying to control the sol-gel reactions as well as phase separation in these systems to obtain unique porous materials particularly from methyltrimethoxysilane (MTMS) and dimethyldimethoxysilane (DMDMS). Flexible aerogels and xerogels based on the methylsiloxane networks are discussed.
