Nano-titania/polyethersulfone composite ultrafiltration membranes with optimized antifouling capacity

TiO2 nanoparticles synthesized via the sol-gel technique were used as an antifouling additive to produce polyethersulfone membranes by the isothermal immersion-precipitation method. In order to finely disperse the TiO2 in the dope, the sol-gel process for their formation involved DMAc as the solvent, same as that used for preparing the dopes. The pore size, water flux, tensile strength, and molecular weight cut-off of the membranes, as affected by the added amounts of TiO2 sol in the dope, exhibited an increase-then-decrease trend. All membranes demonstrated high rejections (>= 92.3%) on filtration against BSA aqueous solutions. In the optimal case, nearly perfect rejection at the permeation flux of 91 LMH/bar was achieved for the membrane containing 1.68 wt% TiO2. This membrane also possessed the highest water flux (181 LMH/bar) and antifouling capability among all prepared membranes; specifically, the flux recovery ratio value remained as high as 94% even after three cycles of filtration-cleaning tests. (C) 2020 Taiwan Institute of Chemical Engineers. Published by Elsevier B.V. All rights reserved.