Mesoporous TMOS–MTMS copolymer silica gels catalyzed by fluoride

Abstract Mesoporous HF-catalyzed tetramethoxysilane-methyltrimethoxysilane (TMOS–MTMS) copolymer silica gels with average pore diameter from 80 to 100 A and narrow pore size distribution have been obtained. Mesoporous TMOS–MTMS copolymer gels with tetramethoxysilane ranging from 10% to 100% were also produced with tetrabutylammonium fluoride (TBAF) catalyst. The pore sizes of TBAF-catalyzed copolymer gels were controlled over a range from 25 to 194 A. Their pore sizes increased with increasing fluoride content to R 2 =0.112 ( R 2 , molar ratio of F/Si) and then level off. The catalytic effect of fluoride on the sol–gel process was investigated. The results suggest that multi-fluorinated silicon species catalyze the silica polymerization.