Use of Pluronic F108 as a Cosurfactant in a Synthesis of Mesoporous Silica Microspheres with Bimodal Pore Size Distribution

Abstract

Large mesoporous silica microspheres with bimodal pore size distributions will be very promising in a special application. Silica microspheres of 10-100 microm in size were synthesized using n-dodecylamine and polymeric surfactant as co-templating agents at room temperature. Surface area and large pore volume of the mesoporous silica microspheres were 884-1009 m2/g and 1.25-1.68 cm3/g, respectively, depending on the reaction conditions. Mesoporous silica microspheres prepared using a short-chained alkylamine surfactant and a long-chained polymeric surfactant exhibited distinct bimodal pore size distribution, that is, small (< 3 nm) and large mesopores (> 20 nm). Pluronic F108, which is a poly(ethylene glycol)-poly(propylene glycol) triblock copolymer, played an important role in the formation of the large mesopores as well as the formation of stable silica microspheres without strong aggregation between particles.