Inducing the Skinned-oriented Asymmetrical Nanofiltration Membranes via Controlled Evaporation Times in Dry/Wet Phase Inversion Process

The effect of evaporation time on the fabrication of fine skinned asymmetric polyethersulfone nanofiltration membrane was studied. Nanofiltration experiment and modeling data revealed that the variation of the evaporation time during dry/wet phase inversion process was found to significantly affect the membrane performance and properties. The evaporation times (5 to 25 s) were found to improve the performance and characteristics of the membrane. As good separation performance was achieved, modeling data and morphological analysis discovered that the optimum evaporation time was found to be at 20 s. At these optimal settings, the fabricated membranes demonstrated the finest structural details and morphologies, and the best key properties (rp, Δx/Ak and ζ), which were within the ranges of commercial nanofiltration membranes.