Study of physico-chemical and antibacterial properties of DBD plasma treated ahimsa silk coated with natural active agent

Abstract

This study investigated the effect of dielectric barrier discharge (DBD) plasma on the physicochemical and antibacterial properties of ahimsa silk fabric. The fabric was pre-treated for 1–5 min with DBD plasma in ambient air. The leaf extracts of Camellia sinensis (Green Tea) and Ocimum sanctum (Tulsi) were applied to the fabric to impart an antibacterial finish. Wettability, SEM, AFM, and tensile strength analyses demonstrated increased hydrophilicity and surface roughness with a slight reduction in mechanical strength. Both ATR-FTIR and XPS indicated an increase in the concentration of polar functional groups, such as -OH, -NH, -CHO, and -COOH, on the surface of the plasma-treated fabric. Antimicrobial activity against Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) was evaluated using the agar plate method and modified Hohenstein test. The results verified the efficacy of plasma-treated fabric, with an approximately 93% reduction in E. coli and a 96% reduction in S. aureus growth that persisted even after three washing cycles. This study suggests that DBD plasma at atmospheric pressure can be used as an eco-friendly technology for modifying the surface of silk fabrics to promote better adherence of plant extracts to the fabric and subsequently enhance their microbial resistance.