Antifouling membranes with bi-continuous porous structures and high fluxes prepared by vapor-induced phase separation

Antifouling poly(ether sulfone) (PES) composite membranes with novel bi-continuous porous structures, high fluxes and hydrophilic surfaces are successfully prepared by simultaneously manipulating the migration of amphiphilic three-block polymer poly(ethylene glycol)-block-poly(propylene glycol)-block-poly(ethylene glycol) (Pluronic (R) F127) to the membrane surfaces and the microstructures of membranes by vapor-induced phase separation (VIPS) method. Effects of the additive mass ratios of Pluronic (R) F127 to PES and VIPS process parameters, including the dissolution and vapor temperature (T), the relative humidity of vapor (RH) and the exposure time to vapor (t), on microstructures of membranes and the surface hydrophilicity of membranes are systematically investigated. When the additive mass ratio of Pluronic (R) F127 to PES is 100%, PES/Pluronic (R) F127 composite membranes with bi-continuous porous structure across the full cross-section can be easily fabricated. For the composite membranes with additive mass ratio of 100%, when t = 1 min, the water contact angles of membranes decrease remarkably when the temperature increases from T = 25 degrees C to T = 40 degrees C. For the PES/Pluronic (R) F127 composite membranes prepared via VIPS method with T = 25 degrees C, RH = 70% and t = 20 min, the water contact angle is as low as 34.5 degrees, the water flux is as high as 236512 L m(-2) h(-1) bar(-1) and the static adsorption amount of bovine serum albumin (BSA) is only 4.6 mu g cm(-2). Valuable guidance is presented in this study about the design and fabrication of antifouling membranes with high flux and hydrophilic surfaces.