Optimization of polysulfone support layer for thin-film composite forward osmosis membrane

ABSTRACT Polysulfone (PSf) has been applied to thin-film composite (TFC) membranes for water treatment and desalination due to its good physicochemical resistance and high affinity for polyamide. In this study, the effect of the PSf support layer synthesis conditions on TFC membrane performance was investigated in order to optimize membrane performance for forward osmosis (FO) process. Scanning electron microscopy, pure water permeability, molecular weight cut-off, and lab-scale FO tests were conducted. The polymer concentration and casting thickness of PSf support layer were critical for determining membrane structure, selectivity, and permeability. The results indicated that TFC FO membrane with PSf support layer fabricated by 15 wt% PSf polymer concentration and 100 μm casting thickness showed the best performance for FO process. The results of this study could contribute to the development of a commercial TFC FO membrane for water treatment and desalination applications.