Spherical particles from tetraorthosilicate (TEOS) sol–gel process with dimethyldiethoxysilane (DDS) and diphenyldiethoxysilane (DPDS) addition

In acid-catalyzed tetraorthosilicate(TEOS) sol–gel process, dimethyldiethoxysilane (DDS) and diphenyldiethoxysilane (DPDS) were added to obtain TDP spherical particles which, according to scanning electron microscopy (SEM) and thermogravimetric (TG) analysis, showed smooth surface and good thermal stability. The formation of the final TDP particles are discussed following three steps, which were much related with the formation of TEOS oligomer and TEOS–DDS reactive skeleton.