Facile and low-cost approach towards a PVDF ultrafiltration membrane with enhanced hydrophilicity and antifouling performance via graphene oxide/water-bath coagulation

Addressed herein is a facile and low-cost approach to endow hydrophobic polyvinylidene fluoride (PVDF) membranes with reliable hydrophilicity and antifouling properties. Porous asymmetric hydrophilic membranes with tunable morphology were facilely fabricated via phase inversion using an aqueous solution of graphene oxide (GO) as the coagulation bath. An increment in pore size and surface roughness was observed for membranes treated by a GO/water-coagulation bath (GB). The bovine serum albumin rejection of GB-treated membranes increased by 38.99% when the concentration of GO in the coagulation bath was 0.5 g L-1. The contact angle of membranes decreased from 75.9 degrees to 58.8 degrees and the water flux increased by 140% when the dosage of GO was 2 g L-1. Furthermore, fouling resistances of membranes revealed that GB-treated membranes had a higher flux recovery ratio (85.7%) than pristine PVDF (43.3%). Meanwhile, the protein adsorption of GB-treated membranes was decreased by 69.3% compared with that of pristine PVDF membranes. The cost of the membranes can be lowered by using a GB approach compared with GO-mixed matrix membranes because of the reusability of GO in a coagulation bath. This research presents an effective method to tailor membrane performance via GB rather than embedding GO in the membrane matrix.