Performance of polysulfone/carboxylated polysulfone membranes

Abstract

Membranes were made from miscible blends of polysulfone (PSf) and carboxylated polysulfone (CPSf) having an average of 0.45 and 0.87 -COOH groups per repeated unit. Membranes made from PSf and CPSf alone showed low separation for NaCl, glucose, polyethylene glycol (PEG) of various molecular weights and bovine albumin, from aqueous solutions under an applied pressure of 50 psig and higher. Membranes made from PSf/CPSf of varied blend composition showed higher separation factors for the above solutes. Highest separation was observed in membranes made from an 80/20 wt% PSf/CPSf 0.45 blend, which yielded a separation factor of 0.60 for NaCl, 0.97 for glucose, 0.98 for PEG and 0.99 for bovine albumin under an applied pressure in the range 50-150 psig. This higher performance is believed to be a result of a synergism between PSf and CPSf 0.45 to give a membrane morphology unique among the PSf/CPSf membranes.