Fabrication of polysulfone ultrafiltration membranes of a density gradient cross section with good anti-pressure stability and relatively high water flux

►The PSF ultrafiltration membrane of a density gradient structure was prepared. ►A good anti-pressure property whereas a rather low flux for PVP ternary system. ►A high flux whereas an unstable anti-pressure property for Ethanol ternary system. ►A good anti-pressure stability and a high flux for the quaternary system.