Environmentally-Friendly RF Plasma Treatment of Thai Silk Fabrics with Chitosan for Antibacterial Property

A 13.56 MHz RF plasma discharge was successfully utilized to coat Thai silk fabrics with chitosan for antibacterial property. Uncolored and untreated Thai silk fabrics were activated in Ar plasma for 5 or 10 minutes with the RF power of 50, 100 or 150 W under the Ar pressure of 4 × 10 –1 or 8 × 10 –1 Torr. After plasma activation, specimens were submerged in a 1% (w/v) chitosan solution at room temperature. FTIR analysis confirmed the presence of chitosan. From SEM analysis, chitosan was observed to coat silk fibers almost everywhere. After having been washed up to 3 times, chitosan coating was still present. Unwashed and washed specimens exhibited an excellent antibacterial property against Staphylococcus aureus , as most can reduce > 93% of the bacteria. Thus, RF plasma treatment can effectively induce chitosan to strongly and durably coat onto Thai silk fabrics.