Engineering silver‐zwitterionic composite nanofiber membrane for bacterial fouling resistance

Abstract

ABSTRACTBacterial attachment and fouling compromise material performance in applications ranging from marine equipment and biomedical devices to water treatment systems. For membrane‐based water treatment systems, bacterial attachment and biofilm formation decrease water purification efficiency and reduces mechanical durability of the membranes. In this work, we present a concurrent electrospinning and copolymerization approach to engineer composite nanofiber membranes comprising of silver nanoparticle containing poly(vinylidene fluoride‐co‐hexafluoropropylene) (PVDF‐HFP‐Ag) nanofibers and [copolymerized zwitterionic sulfobetaine methacrylate‐methacryl polyhedral oligomeric silsesquioxane]‐poly(methyl methacrylate) nanofibers. We characterized the surface morphology, topography, material chemistry, and wettability of the nanofiber membranes with scanning electron microscopy, atomic force microscopy, Fourier transform infrared spectroscopy, and contact angle measurements. We then challenged these nonwoven membranes with two model microbes, Gram‐negative Pseudomonas aeruginosa and Gram‐positive Staphylococcus aureus, and found that the silver‐zwitterionic composite nanofiber membrane exhibited superior bacterial fouling resistance by reducing >90% of bacterial attachment when compared to neat PVDF‐HFP and PVDF‐HFP‐Ag nanofiber membranes. This study demonstrates that concurrent electrospinning enables free‐standing nanofiber membranes with sustained bacterial fouling resistance, with potential in applications in filtration and water treatment technologies for which antifouling strategies are imperative. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47580.