Preparation of bifunctionalized phenylene-bridged periodic mesoporous organosilica for solid-phase microextraction

Abstract

Well-ordered bifunctionalized periodic mesoporous organosilicas (BPMOs), with various mesostructures (like hexagonal p6mm, cubic Iad symmetry), relatively large mesopores, a phenylene-bridged skeleton and vinyl functional groups, were first prepared by co-condensation of 1,4-bis(triethoxysilyl)benzene (BTEB) and triethoxyvinylsilane (TEVS) with a triblock copolymer (P123) as a template under acid conditions. It was found that the mesostructure of the BPMOs can be facilely tuned by altering the fraction of organosilanes in the synthesis mixture. With an increase of TEVS content, the mesostructure changed from p6mm to Iad, until disordered. The mechanisms of the mesophase transformation were discussed based on the adsorption of vinyl groups into the micelles and the relative reactivities of the organosilane precursors. In addition, the potential application of the BPMOs as an effective fibre-coating absorbent is tested in solid-phase microextraction (SPME) analyses.