Al2O3-SiO2-TiO2 composite ceramic membranes from sol-gel processing

The effects of the composition on sol stability, membrane microstructure and surface morphology are discussed. The results showed that the Ti content decreased the gelation time while the effects of Al and Si were not distinct. Large amounts of Ti led to cluster formation in the membranes and the porous structure was destroyed by excessive Si. The presence of Al was helpful in preparing composite membranes with uniform particles and pores. Significantly different morphologies were observed for membranes with different compositions. The more Si the membrane had, the rougher the surface. The existence of Ti smoothed the surface. The composite ceramic membranes have potential for surface modification. 11 refs.