Methylene blue rejection and antifouling properties of different carbonaceous additives-based polyvinylidene fluoride membrane

In the present study, various polyvinylidene fluoride (PVDF)-based membranes were successfully fabricated via non-solvent induced phase separation (NIPS) method utilising different carbon-based materials as additive. The incorporation of reduced graphene oxide (rGO), multi-walled carbon nanotubes (MWCNTs) and GO-MWCNTs hybrid along with titanium dioxide (TiO2) definitely affect the fabricated membrane's morphology, hydrophilicity, porosity, filtration performance and antifouling properties. Based on dead-end filtration measurement, rGO-based PVDF/TiO2 membrane presented excellent pure water flux (2446.887 L/m(2)h) with membrane permeability of 1143.850 L/m(2)hMPa compared to other membranes. Furthermore, the inclusion of rGO and TiO2 also resulted in the highest methylene blue (MB) dye rejection rate (similar to 92%) compared to MWCNTs (62.22%) and GO-MWCNTs (86.69%). It was believed that steric hindrance effect played a major role in enhancing dye rejection performance of PVDF@rGO/TiO2 membrane. Interestingly, in terms of antifouling properties, PVDF@GO-MWCNTs/TiO2 possessed better antifouling properties as indicated by its higher flux recovery ratio (FRR) value of 95.30%. The existence of hydration layer on membrane surface endowed by oxygen-functional groups prevents the contaminant accumulation thus resulted high FRR value.