超声辅助溶胶–凝胶法制备中空纤维 TiO₂ 超滤膜

TiO₂ membranes have been applied in ultrafiltration (UF) separation due to their strong hydrophilicity and good thermochemical stability, but most of them are tubular membranes with low permeation flux and time-consuming preparation. To improve the flux and save the preparation time of TiO₂ membrane, hollow fiber supported TiO₂ UF membranes were prepared via ultrasound-assisted Sol-Gel method by using tetrabutyl titanate as precursor. Effects of acid/titanium molar ratio, ultrasound time and calcination temperature on TiO₂ sols and UF performance of membranes were investigated extensively. The results showed that when the acid/titanium ratio was 0.25, the obtained TiO₂ sol showed an average particle size of 3252 nm, which would be reduced to 1817 nm after ultrasonic treatment for 30 s. Coating with the above TiO₂ sol, defect-free TiO₂ UF membrane with average thickness of 1 μm can be prepared on hollow fiber support by calcining at 350 °C twice. The pure water flux of the obtained membrane was 145 L·m^–2·h^–1·bar^–1, and the dextran molecular weight at 90% rejection of membrane was 2586 Da with corresponding average pore size of 2.5 nm.