Sulfonated graphene oxide incorporated thin film nanocomposite nanofiltration membrane to enhance permeation and antifouling properties

Thin film nanocomposite (TFN) membranes embedded with sulfonated graphene oxide (SGO) were fabricated to improve the hydrophilicity, salt rejection and antifouling of nanofiltration (NF) membrane. In this study, the surface properties and structure of polyamide (PA) layer were improved by incorporating SGO into the PA layer. It was prepared by interfacial polymerization of piperazine (PIP) and trimesoyl chloride (TMC) on the polysulfone substrate surface. The PA layer thickness of TFN membranes decreased and the hydrophilicity and zeta potential of them were improved after incorporating the SGO. According to NF filtration tests, TFN membrane including 0.3 wt% of SGO (TFN 0.3) gave the highest water flux, which was 87.3% higher than that of TFC membrane. Interestingly, despite the significant increase in water permeability, the salt rejection of both membranes was similar due to the improved cross-linking and low molecular weight cut-off (MWCO) of the TFN 0.3 membrane. Furthermore, it showed high antifouling property in long-term NF test, compared to the pristine TFC membrane. The current study may lead to a facile strategy by using SGO nanosheets to improve the hydrophilicity and antifouling properties of NF membrane.