Tuning the morphology of PVDF membranes using inorganic clusters for oil/water separation

Polyvinylidene fluoride (PVDF) membranes with modified membrane morphology were prepared by phase inversion process using iron alkoxide as a novel pore-forming additive (PFA). Higher pure water flux was observed for PVDF/PFA (iron alkoxide) membranes treated with 5% HCl, due to higher porosity produced by the leaching out of the iron alkoxide additive. The untreated membrane containing 0.04% iron alkoxide showed similar to 99% efficiency oil removal from a surfactant-stabilized oil-water emulsion. After acid treatment, there was a slight decrease in the rejection efficiency (similar to 96.5%); however, this membrane still exhibited the highest emulsion flux. The fouling propensity of the membrane with 0.04 wt % iron alkoxide tested in a crossflow condition decreases indicating a lower amount of oil adsorbed onto the surface and a greater flux recovery ratio. The treated membranes showed appreciable anti-biofouling property when the membranes were challenged with Escherichia coli and Bacillus subtilis obtained from freshwater and/or seawater. (c) 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47641.