Green synthesis of silver nanoparticles for ultrafiltration membrane surface modification and antimicrobial activity

This study presents the application of biosynthesized silver nanoparticles (AgNPs) for modifying the surface of ultrafiltration membranes to confer antimicrobial properties. The AgNPs were synthesized using leaf extract of the medicinal plant Mimusops elengi L, and their characterization was carried out using UV spectroscopy, FTIR, XRD, FESEM, HRTEM, and AFM analyses. The optimal conditions for the synthesis of AgNPs were determined to be 240 min of reaction time, pH 9.5, 1:1 (v/v) ratio of initial concentration of precursor to bio-extract, and 323 K temperature. The synthesized AgNPs were found to be spherical with an average size of 20 nm and crystalline in nature. The AgNPs were then deposited on flat sheet polyether sulfone (PES) membranes (MWCO 30 kDa) using the dip coating technique. The deposition of AgNPs on the membrane surface was confirmed using FESEM and EDX analysis. The resulting AgNPs-incorporated membrane demonstrated effective antibacterial activity against E.coli. These findings highlight the potential of biosynthesized AgNPs for developing functionalized ultrafiltration membranes with antimicrobial properties.