Multifunctional electrospun CS/PVA/AgNPs nanofiber membranes for dye removal and antimicrobial water purification

Abstract

There is an urgent need for sustainable methods to purify water contaminated with dyes and pathogenic microorganisms. Conventional treatment technologies often face limitations due to the use of toxic chemicals or complex fabrication processes. In this study, electrospun chitosan/poly(vinyl alcohol)/silver nanoparticle (CS/PVA/AgNPs) nanofiber membranes were fabricated and evaluated for their dual functionality in dye removal and antibacterial activity. SEM, XRD, and EDS analyses confirmed the formation of quasi-spherical AgNPs and their uniform distribution within the polymer matrix. Morphological analysis revealed that the incorporation of AgNPs into the CS/PVA matrix reduced the fiber diameter from 120-230 nm to 99-158 nm and significantly decreased bead formation. Congo Red adsorption reached equilibrium within 120-150 min, with capacities increasing with dye concentration. Maximum adsorption occurred at pH 4, and the membrane retained over 60% efficiency after two regeneration cycles. Additionally, the CS/PVA/AgNPs membrane exhibited strong antibacterial activity, achieving up to 99% inhibition against Escherichia coli and Staphylococcus aureus. Overall, these results highlight the potential of CS/PVA/AgNPs nanofiber membranes as multifunctional, eco-friendly materials for simultaneous dye adsorption and antimicrobial water purification.