High performance polyethersulfone microfiltration membranes having high flux and stable hydrophilic property

High performance polyethersulfone microfiltration membranes with a high flux and stable hydrophilic character were successfully prepared by vapor induced phase separation coupled with non-solvent induced phase separation method. Pluronic®, a poly(ethylene oxide)-b-poly(propylene oxide)-b-poly(ethylene oxide) triblock copolymer and triethylene glycol (TEG) were used as hydrophilicity modification agent and non-solvent, respectively. Casting solution composition (non-solvent and additive content) and process condition (exposure time before coagulation and relative humidity) were optimized to obtain these membranes. The resulting membrane characteristics, which include hydraulic permeability, pore size distribution, surface hydrophilicity, chemical composition and membrane morphology, were investigated. The membrane performance was examined by investigation of adsorptive fouling and microfiltration using solutions of bovine serum albumin as the model system. The results suggest that the non-solvent content (TEG) and the exposure time were the most critical parameters to obtain high-flux membranes, whereas the concentration of Pluronic was important to obtain hydrophilic property. The increase in resistance towards both adsorptive and microfiltration fouling was clearly observed. The surface chemistry and wettability of the resulting membranes did not change after incubating in water (40 °C) for a period of 10 days.