Synthesis of periodic mesoporous organosilicas with chemically active bridging groups and high loadings of thiol groups

Abstract

Chemically active isocyanurate-bridged periodic mesoporous organosilica materials with high loadings of pendant thiol groups have been synthesized via co-condensation under acidic conditions, using the triblock copolymer EO20PO70EO20 (P123) as template and a mixture of mercaptopropyl-containing silane and isocyanurate-containing silsesquioxane to form the framework. The obtained SH–ICS–PMOs were characterized by XRD, transmission electron microscopy (TEM), solid state 13C and 29Si MAS NMR spectroscopy, and N2 physical sorption. The data show that well-ordered SH–ICS–PMOs were obtained with 40% of the framework Si atoms bearing the thiol pendant groups. Interestingly, the introduction of the thiol groups improved the mesostructural ordering and favored the cross-linking of the pore walls. The determination of Hg2+ uptake from aqueous solution as a test case showed that both the bridging ICS groups and the pendant thiol groups in the SH–ICS–PMOs are active in adsorbing Hg2+. Our study demonstrated that well-ordered periodic mesoporous organosilicas are capable of supporting both chemically active bridging groups and active pendant groups with high loadings.