One-step synthesis of hydrophobic mesoporous silica ellipsoidal particles with a bimodal mesopore system

Abstract

Highly CH3-functionalized mesoporous silica ellipsoidal particles with bimodal mesopore structure were prepared via a one-step route using polymethylhydrosiloxane (PMHS) and tetraethoxysilane (TEOS) with triblock copolymer P123 as template under acidic conditions. N2 adsorption–desorption, XRD, HRTEM, SEM and 29Si MAS NMR were used to characterize the obtained material. The introduction of PMHS into the synthetic system led to the formation of a bimodal mesopore system consisting of framework mesopores of ∼7.2nm and textural mesopores of ∼29.4nm. The two scale pores were directly observed in HRTEM images and indirectly proved by the two-step increase in N2 adsorption–desorption isotherm. Also, PMHS played an important role in morphology controlling and organic functionalization, ensuring monodisperse ellipsoidal particle morphology and high CH3 functionalization degree of the mesoporous silica product. Subjected to removing highly diluted nonylphenol from aqueous solution, the hydrophobic bimodal mesoporous silica ellipsoidal particles showed high adsorption performance.