Achieving antibiofouling on microporous membranes prepared with a green solvent via spraying an aqueous antifouling copolymer solution

This study highlights a comprehensive investigation into the fabrication and characterization of sustainable membranes for antifouling applications. It utilizes γ-valerolactone as a green solvent to obtain microfiltration polyvinylidene difluoride (PVDF) membranes, and leverages spray-coating technique to modify these membranes. This research aims to enhance the surface and bulk properties of PVDF membranes while promoting sustainable practices. Chemical analyses of the membranes reveal that the surface and bulk of the membranes were successfully modified. Dynamic water contact angle measurements indicated that a 10 mg/mL coating solution (PVDF_10) resulted in the highest hydrophilicity. Different biofouling tests were conducted using proteins and bacteria. In adhesion tests with BSA, and E. coli, the PVDF_10 membrane demonstrated the highest resistance, reducing adhesion by approximately 83 % and 94 %, respectively. Additionally, cyclical water/bacterial filtration tests demonstrated that PVDF_10 membrane achieved a higher flux recovery ratio compared to commercial hydrophilic PVDF membranes. The modification remained stable even after 6 weeks of immersion in water. This study highlights the potential of γ-GVL and the spray-coating technique as environmentally friendly solvents and modification techniques for producing green antifouling PVDF membranes, aligning with sustainable practices and significantly enhancing membrane performance.