PROCESS FOR PRODUCING POROUS SILICA, AND POROUS SILICA

摘要

Provide a porous silica which can be easily formed into various shapes excellent transparency, capable to be nanoparticulated, capable to be obtained at a high efficiency even when a cationic surfactant having 7 or less carbon atoms is used. Alkoxysilane is dispersed with a cationic surfactant in which a hydrophobic moiety has 2 to 7 of carbon atoms, and added water of which pH is adjusted to 0-2 with the amount of 2-4 equivalents to the alkoxysilane, and mildly hydrolyzed to obtain a monolithic mesoporous silica of which a pore diameter is not less than 0.5 nm and less than 2 nm. Furthermore, a pore diameter can be slightly controlled by adding an organic silane to the system. By adding polyethylene glycol to the synthesis system, a monolithic mesoporous silica nanoparticle is obtained. A precursor solution prior to gelation is: (1) droped to a basic aqueous solution to obtain a mesoporous silica bead or the like; (2) spincoated on a substrate to obtain a thin film; or (3) sprayed with a spinner to obtain a fiber, respectively.