Preparation and characterization of vinyl-functionalized mesoporous SBA-15 silica by a direct synthesis method

摘要

Vinyl groups were used to functionalize the pore channels of mesoporous SBA-15 materials by the co-condensation of tetraethyl orthosilicate (TEOS) and triethoxyvinylsilane (TEVS) in the presence of poly(ethylene glycol)-B-poly(propylene glycol)-B-poly(ethylene glycol) (P123) surfactants under acidic conditions. The final materials were investigated in detail by means of FT-IR, XRD, TEM, solid state NMR and N_2 adsorption, in order to study the effect of vinyl concentration on their mesoscopic order and pore structure. The results show that vinyl groups are attached covalently to the pore wall of SBA-15 after modification. The mesoscopic architecture almost remains intact upon functionalization, with only a minor decrease of the intensity of (110) diffractions for the 20 mol% TEVS-functionalized samples, which still preserve a desirable pore structure, with a surface area of 883.7 m~2/g, a pore volume of 0.98 cm~3/g and a mean pore size of 4.4 nm.