Spray-dried mesoporous silica spheres functionalized with carboxylic groups

Abstract

Spherical mesoporous particles functionalized with carboxylic groups were prepared through a co-condensation route by spraying a solution containing hydrolyzed alkoxide (tetraethoxysilane) and an organosilane (4-(triethoxysilyl) butyronitrile)), in the presence of nonionic block copolymer as template. Samples have been then treated with sulfuric acid to remove the template and to hydrolyze simultaneously the –CN to –COOH groups. The mesoporous spheres show high specific surface area and narrow pore size distribution. TG and FT-IR analysis confirm the incorporation of the carboxylic moieties, whose amount results ca 1meqg−1 by titration with alkali solution. The mean size of mesoporous spheres can be ranged from few microns to submicron by varying the initial precursor concentration of spray-dried synthesis solution.