Author/Authors :
He، نويسنده , , Liu and Powers، نويسنده , , Kevin and Baney، نويسنده , , Ronald H. and Gower، نويسنده , , Laurie and Duran، نويسنده , , Randolph S. and Sheth، نويسنده , , Piyush and Carino، نويسنده , , Stephen R.، نويسنده ,
Abstract :
Mesoporous HF-catalyzed tetramethoxysilane-methyltrimethoxysilane (TMOS–MTMS) copolymer silica gels with average pore diameter from 80 to 100 Å 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 Å. Their pore sizes increased with increasing fluoride content to R2=0.112 (R2, 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.
