A Preliminary Investigation of a Novel Series of Silica Gels

Abstract

Silica gels may be produced by the hydrolytic polycondensation of organic silicates such as tetraethyl ortho silicate (TEOS) under appropriate conditions. These systems are of interest to the ceramic industry for making high purity silicate glasses at low temperatures. These silica gels may have application as drug delivery systems.

The gelation rates due to the hydrolytic polycondensation process depend on the concentration of TEOS and water, the temperature, and the presence of acid or base catalysts. A wide variety of polymeric silica gels having different polymeric matrices and pore sizes are possible. Of the alcohols and glycols screened for silica gel formulation, ethanol and glycerol appear to have a unique role in the gelation process although they do not appear to contribute directly to the hydrolytic polycondensation process.