Structural analysis of poly(dimethylsiloxane) modified silica xerogels

A new type of inorganic-organic hybrid material incorporating poly(dimethylsiloxane) (PDMS) in tetraethoxysilane (TEOS) based glassy gels has been produced by a sol-gel process. SAXS and SEM studies indicate that these PDMS modified silica xerogels possess multiple size-scale morphologies, ranging from Angstroms to micrometers. The multiple-level hybrid materials show improved structural integrity relative to pure sol-gel glasses (xerogels). The effect of reaction time, water content, as well as content and molecular weight of PDMS on the structure of such materials were studied. These processing variables affect the relative rates of hydrolysis and condensation reactions, and consequently change the microstructure of the final product. (C) 1999 Published by Elsevier Science B.V. All rights reserved.