BACKGROUND The concentration polarization and membrane fouling are two important factors, which can greatly reduce the forward osmosis (FO) performance and the service life of membranes. Optimizing the supporting layer structure and improving the hydrophilicity of the supporting layer are effective means to improve the FO performance and the anti-fouling performance of thin-film composite (TFC)-type membranes. RESULTS A novel hydrophilic TFC-type FO membrane with a macroporous polymer-brush-grafted polysulfone (PSf) supporting layer was fabricated. The prepared TFC-type FO membrane (g-FO-3) showed remarkable FO and anti-fouling performance. The water flux of g-FO-3 (43.0 L m(-2) h(-1)) was nearly 2.6 times the conventional TFC-type PSf-based FO membrane (16.8 L m(-2) h(-1)) and 1.8 times the TFC-type FO membrane with macroporous PSf supporting layer but without polymer grafting (24 L m(-2) h(-1)) in AL-DS mode (the active layer facing the draw solution), with water as the feed solution and 2 mol L-1 sodium chloride as the draw solution. In addition, the low J(s)/J(w) value of g-FO-3 indicated an excellent separation selectivity. Furthermore, the FO membrane kept a water flux recovery rate of 95% after the eight-cycle fouling tests. CONCLUSION The hydrophilic polymer-brush-grafted PSf macroporous supporting layer of the FO membrane provides a convenient and efficient means to improve the FO and the anti-fouling performance of the TFC-type FO membranes. (c) 2019 Society of Chemical Industry