Microstructures and mechanical properties of organically modified silicate prepared under various process conditions

Inorganic–organic hybrids or organically modified silicates (ORMOSILs), with tailorable optical and electrical properties depending on the inorganic and organic components chosen, processing conditions, etc., offer many new exciting properties that lead to different applications. In this study, tetraethoxysilane (TEOS) and poly(dimethylsiloxane) (PDMS) were chosen as the inorganic and organic components respectively, to prepare ORMOSIL matrix. Silanol-terminated PDMS can condense with oxide precursors to produce metal–O–Si bond and is known for its superior relaxation. The effects of H2O/TEOS ratio, PDMS molecular weight and different reaction schemes (i.e. reaction order) on the microstructures and mechanical properties of the SiO2–PDMS ORMOSILs have been studied. Attempts are made to explain the results in the light of presently available theories.