Structural and textural evolution of bimodal mesopore silica xerogels during aging and drying

The effects of aging and drying conditions on the structural and textural properties of surfactant-templated silica xerogel with bimodal mesopore distribution characteristic (designated as BMS) prepared under base-catalyzed sol-gel process were investigated. It was found that the change of aging and drying conditions would influence not only the size and the packing geometry of surfactant-encapsulated silica primary particles, in turn the textural mesoporosity, but also the polymerization extent of framework pore wall which would determine the framework mesopore properties. Both the lower aging temperature and the higher drying temperature are conducible to the formation of a high-quality BMS silica xerogel. However, over the range studied, aging and drying conditions had no significant effect on the framework mesopore sizes, though the corresponding specific surface areas and pore volumes can be varied markedly.