Hypochlorite Resistant Graphene Oxide Incorporated Ultrafiltration Membranes with High Sustainable Flux

Poly(ether sulfone) (PES) is commonly used polymer in ultrafiltration (UF) membranes which, due to its hydrophobic nature, frequently incorporates the copolymer, polyvinylpyrrolidone (PVP), to improve its hydrophilicity. Membranes are periodically disinfected using bleach which chemically degrades PVP, thus removing its hydrophilic advantage. The utility of graphene oxide (GO) is compared with PVP as a hydrophilic and chemically stable additive in PES UF membranes. The performances of the membranes were evaluated by comparing pure water flux, contact angle, and fluxes during fouling tests before and after hypochlorite chemical washing after fouling (CWAF). Membranes containing low concentrations (<0.05% wt) of GO had an increase in rejection, lower porosity on average leading to less severe fouling, a higher sustainable flux, and greatly improved reversible fouling especially after CWAF tests compared with membranes containing PVP (1% wt). This research indicates that low concentrations of GO to PES can greatly improve the fouling of PES UF membranes while retaining a hydrophilic properties and provide improved chemical stability after hypochlorite exposure.