Synthesis of SBA-15 mesoporous silica via dry-gel conversion route

Abstract

Dry-gel conversion method has been successfully applied for the synthesis of mesostructured silica SBA-15 materials with the particle size in submicron range. The effects of duration of self-assembly and dry-gel conversion on the structure of SBA-15 are investigated. Submicron particles with uniform mesoporous structure were formed during the first 2 h of static hydrolysis and self-assembly. The particle morphology and pore properties were not obviously influenced by the duration of self-assembly. Without dry-gel conversion, the mesoporous structure significantly shrank after calcination due to its weak stability of mesostructure. After steam-assisted dry-gel conversion at 100 °C, the pore wall is consolidated without damaging the mesostructure because of the support of surfactant micelles inside the pore channels. The larger surface area and pore volume of mesostructured silica were well preserved after calcination. In addition, the surface morphology and particle size were not affected by dry-gel conversion, and submicron particles of mesostructured silica SBA-15 materials were obtained after calcination at 550 °C.