Grafting of poly(N-isopropylacrylamide) (NIPAM) on surface of TFC FO membrane to improve fouling-resistance and cleaning efficiency

Abstract

Recently, forward osmosis (FO) process has been considered as a substitute desalination method. Fouling in the FO process is relatively lower than that in pressure-driven membrane process, but the fouling severely limits FO membrane performance. Poly(N-isopropylacrylamide) (PNIPAM), which is one of the thermo-responsive polymer, was grafted on the surface of commercially available HTI thin film composite (TFC) forward osmosis (FO) membranes using radical graft to improve organic fouling resistance and cleaning efficiency. The successful grafting of PNIPAM on TFC membrane surface was confirmed by ATR-FTIR and XPS. PNIPAM-grafted membranes showed better resistance to organic fouling compared to the neat membranes. Additionally, PNIPAM-grafted membrane exhibited higher cleaning efficiency. These results indicate that the application of thermo-responsive polymers to FO membranes can enhance fouling-resistance and cleaning efficiency during the FO desalination process.