Ultrafiltration membranes based on hybrids of an amphiphilic graft copolymer and titanium isopropoxide

Abstract

Graft copolymer poly(vinyl chloride)-g-poly(oxyethylene methacrylate) (PVC-g-POEM) is combined with titanium isopropoxide (TTIP) to form hybrids that undergo phase separation in a water bath. The water permeance of the PVC-g-POEM membrane increases by hybridization with TTIP owing to an increase in the surface pore size and porosity. Upon heating to 80 8C, the water permeances of PVC-g-POEM and PVC-g-POEM/TTIP decrease owing to the increased thickness of the top layer. However, the bovine serum albumin (BSA) rejection of PVC-g-POEM increases, while that of PVC-g-POEM/TTIP decreases. This is attributed to accelerated dissolution of TTIP at 80 8C, resulting in a large number of surface pores. The antifouling performance is significantly improved by TTIP addition and heating owing to increased hydrophilicity, as confirmed by contact angle, O/C atomic ratio, and water content measurements. The PVC-g-POEM/TTIP membrane prepared at 25 8C shows the best performance [338 L m 22 h 21 bar 21 (LMH) water permeance, 89.4% BSA rejection, and 91.9% flux ratio recovery].

Fluorine-Containing, Self-Assembled Graft Copolymer for Tuning the Hydrophilicity and Antifouling Properties of PVDF Ultrafiltration Membranes

“…However, these methods often result in decreased water permeance because the surface pores of the membranes are easily blocked. Alternatively, blending copolymers as additives during membrane preparation yields membranes with controlled pores and high porosity [19,[24][25][26]. This approach allows for the efficient rejection of foulants without sacrificing the water permeance.…”