A hybrid mesoporous membrane synthesized by microwave-assistance: Preparation and characterization

A hybrid mesoporous membrane composed of mesoporous silica rods inside the channels of polycarbonate (PC) filtration membrane was synthesized for the first time by employing a microwave-assisted method. In order to retain the structural integrity of final product as membrane, surfactants were removed from as-synthesized hybrid membrane by solvent extraction instead of calcination. The results of scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), transmission electron microscopy (TEM), N2 adsorption–desorption and thermal gravimetric analysis (TGA) indicate that silica rods with 200 nm in diameter and 9 μm in length grew in the confined cylindrical spaces of PC membrane. Both of columnar and circular mesopore orientations were observed in the silica rods while the average diameter of the mesopores is about 3.0 nm. Moreover, the compactness of hybrid mesoporous membranes with or without solvent extraction was investigated through the molecule permeation experiments with a U-tube molecule transport setup. The results show that such a hybrid mesoporous membrane is permeable for small molecule but impermeable for biomacromolecule, and the transport flux of small molecule across the PC-templated hybrid mesoporous membrane with removal of surfactants is larger than that across the PAA (porous anodic alumina)-templated or the PC-templated hybrid mesoporous membrane without removal of surfactants, which indicates that the transport flux of molecule across such hybrid mesoporous membranes is related to the surfactants existed in the membranes.