Tetramethoxysilane as a convenient silicon source for phase control of cubic SBA-1 mesostructures

Abstract: The critical role of silica precursors in the synthesis of the cubic SBA-1 mesophase under strongly acidic conditions at different synthesis temperatures has been investigated. The undesirable phase selection in the synthesis of SBA-1 that occurred at high temperatures can be prevented when the conventional silica source tetraethoxysilane (TEOS) is replaced by tetramethoxysilane (TMOS). The presence of higher concentration of methanol due to the faster hydrolysis rate of TMOS, which effectively serves as cosolvent to maintain the high surface curvature of surfactant micelles, is a key factor for preservation of the cubic SBA-1 mesostructure at synthesis temperature higher than 313K. [Copyright &y& Elsevier]