Rsa. Delange et al., POLYMERIC-SILICA-BASED SOLS FOR MEMBRANE MODIFICATION APPLICATIONS - SOL-GEL SYNTHESIS AND CHARACTERIZATION WITH SAXS, Journal of non-crystalline solids, 191(1-2), 1995, pp. 1-16
Polymeric SiO2 and binary SiO2/TiO2, SiO2/ZrO2 and SiO2/Al2O3 sols, fo
r ceramic membrane modification applications, have been prepared by ac
id-catalyzed hydrolysis and condensation of alkoxides in alcohol. The
sols were characterized with small angle X-ray scattering, using synch
rotron radiation. Directly after synthesis, the sols were found to con
sist of weakly branched polymeric structures with typical fractal dime
nsions of around 1.5 and radii of gyration of approximate to 2 nm. The
aggregation for silica sols obeys the tip-to-tip cluster-cluster aggr
egation model in the initial stages. Prehydrolysis of TEOS was found t
o be the best method to synthesize polymeric binary systems. Based on
an analysis of film formation from sols consisting of weakly branched
polymers, it is expected that consolidation of these polymers will res
ult in microporous materials.