A novel photo-induced synthesis of carboxymethyl chitosan-silver nanocomposite: preparation, characterization and antibacterial efficacy of cotton finished fabrics

A novel, facile, and eco-friendly photochemical approach was developed for the synthesis of carboxymethyl chitosan-silver nanocomposites (CMC-Ag-nanocomposites). The synthesis utilized a water-soluble 4-(trimethyl ammonium methyl) benzophenone chloride photo-initiator and a 125W medium-pressure Hg lamp, marking the first time this specific initiation system has been used for CMC-Ag composites. The mechanism of silver ion reduction (Ag + → Ag 0 ) was established, and nanoparticle formation was monitored via UV–Vis spectrophotometry. Optimized nanocomposites were applied to cotton fabrics using a pad-dry-cure technique to impart antibacterial properties. Characterization through FTIR, TEM, and XRD confirmed the successful synthesis, while SEM was used to examine the surface morphology of the finished fabrics. Results revealed that uniform spherical AgNPs (2–20 nm) were well-dispersed within the CMC matrix without significant aggregation. The treated cotton fabrics exhibited outstanding antibacterial efficacy against both Staphylococcus aureus and Escherichia coli , retaining significant activity even after twenty washing cycles. This study demonstrates a sustainable and effective pathway for producing high-performance antibacterial medical textiles.