Fabrication of Highly Efficient and Reusable Antibacterial Membrane-Zeolitic Imidazolate Framework Nanocomposites

In this study, we report the fabrication of a nanocomposite membrane through electrospinning of poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) solution containing zinc chloride, followed by an alternate dipping method to induce in situ growth of zeolitic imidazolate frameworks (ZIFs) directly on the nanofiber surfaces. This approach enabled controlled deposition of ZIF-8 or ZIF-L onto the membrane, optimizing surface exposure while preserving the inherent porosity and hydrophobicity of the fibrous scaffold. Subsequent postsynthetic metalation with dilute silver nitrate solutions (0.05–0.1 wt %) yielded Ag/ZIF-functionalized membranes with tunable silver content, as confirmed by X-ray photoelectron spectroscopy and scanning electron microscopy. Comprehensive characterization of morphology, porosity, thermal stability, and surface chemistry was conducted. Powder X-ray diffraction revealed formation of ZIF-8 at precursor concentrations (≤1.5 wt %), and ZIF-L (≥2 wt %). Silver incorporation was most efficient at lower dipping concentrations, minimizing ZIF degradation and enhancing surface-bound Ag loading, which translated into amplified bactericidal activity. Antibacterial assays against E. coli and S. aureus demonstrated nearly complete inhibition, with minimum inhibitory concentrations as low as 6.6 μg/mL, alongside excellent overall reusability. These results demonstrate the potential of the developed membranes for advanced filtration systems, reusable face masks, and other biomedical devices requiring durable antimicrobial performance.