Mussel-inspired graphene oxide-based mixed matrix membranes for improving permeability and antifouling property

Abstract

A multi-functional bio-inspired graphene oxide (GO) nanosheet was prepared firstly by successively modifying GO nanosheets with polydopamine (GO-PDA) and lysine (GO-PDA-LYS). Subsequently, the modified GO-blended polyvinylidene fluoride (PVDF) (PVDF/(GO-PDA-LYS)) MMMs were fabricated via non-solvent induced phase separation (NIPS) method. The presence of biomimetic GO-based nanosheets with good compatibility further improves the hydrophilicity of MMMs and endows them with favorable antifouling and antibacterial properties. The resultant MMMs show a competitive rejection rate (95.2%) of bovine serum albumin (BSA) and high pure water permeability of 850 L m-2h−1 bar−1, which is 7 times higher than that of the original PVDF membrane, as well as a high flux recovery ratio of over 80%. Moreover, the results of the Raman spectroscopy demonstrate that GO-PDA-LYS nanosheets are more evenly dispersed on the membrane surface than GO or GO-PDA nanosheets due to their better compatibility, thereby further improving antifouling and antibacterial performance of MMMs. This multi-functional biomimetic GO-PDA-LYS nanosheet provides new insights into an effective strategy for synchronously enhancing the water permeability, antifouling and antibacterial performance of MMMs.