Ultrafast Sonochemical Synthesis of Methane and Ethane Bridged Periodic Mesoporous Organosilicas

Abstract

Periodic mesoporous organosilicas (PMOs) with methane and ethane bridging groups were synthesized by the condensation of bis(triethoxysilyl)methane and bis(triethoxysilyl)ethane, respectively, in an ultrafast sonochemical method with a short reaction time of 30 min using a cationic template (1-hexadecyl)trimethylammonium bromide (HTABr). Subsequently, the template HTABr was extracted by another 30 min of sonication in an acetone/HCl mixture. The whole experimental process for the synthesis and extraction of the PMOs took about 1 h, which is much shorter than any other reported methods. Both the PMOs have very high surface areas of 1200-1390 m(2) g(-1) with a narrow pore size distribution of approximately 3 nm. This sonochemical method further extended for the synthesis of large pore (pore size of approximately 5 nm) methane and ethane bridged PMOs using a triblock copolymer Pluronic P123 as template. The methane and ethane bridged PMO materials thus obtained were characterized by small-angle X-ray scattering, transmission electron microscopy, nitrogen sorption, and solid-state NMR techniques.