Synthesis and applications of TEOS PDMS hybrid material by the sol-gel process

An organically modified silicate, ormosil, was synthesized with an inorgani c precursor, (tetraethoxysilane, TEOS) and an organic precursor [poly(dimet hylsiloane), PDMS] through sol-gel chemistry. The bonding characteristics o f the composite were investigated via glass transition temperatures (T-g) a nd a hybridization model of TEOS and PDMS was illustrated schematically. Th e variation of T-g with the ratios of HCI/TEOS and TEOS/PDMS was observed. Ormosil sols for coating were obtained with TEOS/PDMS ratios from 60:40 to 90:10 and the best ormosil sol as the host of a dye laser was obtained from a ratio of 90:10. As the HCI/TEOS ratio was increased, higher T-g values w ere obtained but holes formed in the coated surface and laser output dimini shed. Dimerization of organic molecules was detected in the enlarged pore s ize of the host due to an increase in the ratio. The effects of HCl and PDM S on bonding characteristics were measured by dynamic mechanical thermal an alyser (DMTA). UV/VIS spectrophotometry, spectrofluorimetry and scanning el ectron micrography (SEM) were used to obtain the properties relating to thi s study of inorganic-organic composites. Copyright (C) 1999 John Wiley & So ns, Ltd.