Green-engineered multifunctional antimicrobial and UV-shielding fabrics using mono- and bimetallic ionic chitosan composite nanogels

We report the green synthesis and functional evaluation of monometallic (Ag#HG) and bimetallic (Ag#HG#Ti) nanocomposite hydrogels using clove essential oil as a reducing agent and poly-triphenylphosphonium chitosan hydrogel (HG) as a stabilizing scaffold. These nanocomposites were applied to cotton fabric (CF) using the pad-dry-cure method to produce multifunctional textile coatings. Characterization confirmed the formation of nanocomposites and their uniform deposition on the fabric surfaces. The fabrics exhibited increased hydrophobicity, with water contact angles ranging from approximately 0° (CF) to 151.3° (CF#Ag#HG#Ti). Testing revealed improved tensile strength (67.1 N to 85.7 N) and surface roughness, with the preservation of breathability. UV-protection capacity improved significantly, with UPF values increasing from 2.1 (CF) to 45.1 (CF#Ag#HG#Ti), indicating excellent UV-blocking from Ag and TiO₂ integration. Antimicrobial assays showed broad-spectrum efficacy, with CF#Ag#HG achieving the largest inhibition zones (up to 36 mm against Candida albicans) and CF#Ag#HG#Ti showing durable activity (> 90% bacterial reduction) after 15 washing cycles. Cytotoxicity testing on human skin fibroblast (HSF) cells confirmed high biocompatibility, maintaining > 60% viability at 250 µg/mL, outperforming 5-fluorouracil (5-Fu) treatment. These multifunctional nanocomposites provide a robust platform for antimicrobial, UV-protective, and water-repellent textile technologies with excellent durability and safety profiles.