Asymmetric Reverse Osmosis Sulfonated Poly(aryl ether) Sulfone Copolymer Membranes

Reverse osmosis membranes based on partially disulfonated copolymers of biphenol and aryl sulfone (BPS) have been studied in an asymmetric architecture. In these films, BPS represents both the porous support and solute rejection layer of the membrane. A procedure was developed to fabricate these asymmetric films through phase inversion of BPS solutions. Recipe optimization and the inclusion of several post-treatment steps to densify the rejection layer and heal defects are described in detail. To achieve competitiveness with commercial polyamide membranes, several challenges for continued improvements and commercialization are also discussed.