Efficient preparation of a novel PVDF antifouling membrane based on the solvent-responsive cleaning properties

In this paper, zein was first used as a stimuli-responsive anti-fouling medium to improve the fouling release ability of polyvinylidene fluoride (PVDF) ultrafiltration membranes based on the dissolution properties of zein in various solvent systems. The PVDF/zein blend membrane was prepared by the conventional non-solvent induced phase separation (NIPS) method, and the zein component was introduced into the modified PVDF membrane matrix without decreasing the separation performance. The solvent with a low concentration for zein was used as the cleaning agent to clean the fouled membranes, and the modified PVDF membrane could exhibit a very high water flux recovery ratio (> 95%) with the enhanced fouling release ability. Based on the solvent response characteristics, the preferential adsorption properties of zein for organic solvents such as ethanol and acetone made it preferentially swell in the cleaning agent to change the interfacial properties of the modified PVDF membrane and made pollutants easier to be removed by destroying the physical and chemical attachment of pollutants on the surface and pores of the fouled membranes. This article aims to provide a convenient way to improve the antifouling and long-term separation performances of the porous separation membranes.