Preparation of La-doped TiO₂ ultrafiltration membrane by templating of block copolymer

La-doped TiO₂ ultrafiltration membrane was prepared via a block copolymer assisted polymeric Sol-Gel process. The effects of La doping on the mechanical property of TiO₂ gel, the crystal phase transformation and mesostructure of TiO₂ materials were investigated by dynamic mechanical analysis (DMA), N₂ adsorption-desorption, X-ray diffraction (XRD), and X-ray photoelectron spectroscope (XPS) analysis. Results showed that the mechanical strength of the formed gel was significantly improved by the introduction of lanthanum, by which the risk of the membrane cracking could be reduced largely. X-ray diffraction analysis showed that La doping inhibited the TiO₂ crystal phase transformation and the anatase phase could still keep stable at 800℃. Furthermore, the BET surface area and porosity of the materials were also increased. The optimal La doping amount was 0.74 g, and the formed TiO₂ sol particle size was 10 nm. Futher more, the filtration experiments showed that the La-doped TiO₂ ultrafiltration membrane possessed a pore size of 2.3 nm, while the pore size of the La-undoped TiO₂ membrane was 2.7 nm.