Water-Resistant Poly( vinyl alcohol)-Silica Hybrids through Sol-Gel Processing

Poly(vinyl alcohol) (PVA)-silica hybrids with exceptionally reduced solubility in water were synthesized. The hybrid xerogels were fabricated through sol-gel processing of a mixture of PVA and the acid-catalyzed silica precursor tetraethoxysilane. The effects of varying ratios of PVA and silica precursor on the surface structure, thermal properties, crystallinity, and solubility of the hybrids were investigated. Unlike the highly water-soluble nature of PVA, all the hybrids displayed considerably reduced solubility in water. This anomalous behavior of PVA in the hybrids can be attributed to the unavailability of its pendant -OH groups. Water-resistant PVA-silica hybrids can find applications in various technologies requiring biocompatible systems that are stable in aqueous environments.