Novel GO-blended PVDF ultrafiltration membranes

Using the immersion phase inversion process, polyvinylidene fluoride (PVDF) and graphene oxide (GO) dissolved in N, N-dimethylacetamide (DMAc) were combined to prepare organic–inorganic-blended ultrafiltration membranes. The prepared GO-blended PVDF membranes were characterized by several analytical methods, such as Fourier transform infrared (FT-IR) spectroscopy, scanning electron microscopy (SEM), contact angle measurements and permeation tests. Owing to the hydrophilic nature of GO, the GO-blended PVDF membranes appeared to be more hydrophilic and have higher pure water fluxes recovery ratio than the unblended PVDF membranes. The beneficial effects of adding GO to the PVDF membrane, in terms of mechanical strength, permeation properties, and anti-fouling performance, were also examined. The results show that, when the content of GO added in the casting solution was 0.20 wt.%, the properties and structure of the blended membranes can be improved obviously. The permeability of the blended membrane increases by 96.4% with a slight change of retention; the tensile strength increases by 123%. Moreover, the contact angle decreases from 79.2° to 60.7°, which implies that the anti-fouling ability of the membrane is improved.