Plasma treatment applied in the pad-dry-cure process for making rechargeable antimicrobial cotton fabric that inhibits S. Aureus

Abstract

In this paper, variables in an environmentally friendly rechargeable antimicrobial finishing process were studied. Cotton fabric was treated with nitrogen plasma after padding with 5,5-dimethylhydantoin (DMH) when fabric was treated through the pad-dry-cure method, that is, pad-plasma-dry-cure. After that, fabric was chlorinated with sodium hypochlorite to impart antimicrobial property and function. An orthogonal array testing strategy was used in the finishing process for finding the optimum treatment condition. Ultraviolet spectroscopy, scanning electron microscopy and Fourier transform infrared spectroscopy were employed to evaluate the properties of treated cotton fabric, including concentration of chlorine on cotton fabric, morphological properties of the surface of cotton fabric and function groups on the cotton fabric. The results showed that cotton fabric finished with DMH with the help of plasma treatment followed by chlorination inhibits microorganisms effectively, the antimicrobial property against Staphylococcus (S.) aureus was rechargeable and durability of antimicrobial property was improved by plasma treatment.

Regenerable Antibacterial Cotton Fabric by Plasma Treatment with Dimethylhydantoin: Antibacterial Activity against S. aureus

“…The DMH padded cotton fabric was then dried at 80 °C for 5 min, similar to previous studies [24][25][26][27]. The dried fabric was then treated with plasma and cured at 120 °C, 140 °C, or 160 °C for 5 min (i.e., pad-dry-plasma-cure).…”

“…Non-ionic detergent, Diadavin EWN-T 200% (Tanatex, Leverkusen, Germany) (2%), was used for cleaning the fabric at pH 7 at 50 • C for 30 min. After cleaning, the fabric was rinsed with deionised water to remove detergent, oil, and impurities and dried at 80 • C for 20 min [23][24][25][26][27]. The cleaned fabric was then conditioned at 65% ± 2% relative humidity and 20 ± 2 • C for at least 24 h prior to further use.…”

“…In the APP treatment system, the plasma jet was placed vertically above the fabric (Figure 2) [23][24][25][26][27]. As described in detail previously [23][24][25][26][27], helium (flow rate = 9.6 L/min) and nitrogen (flow rate = 0.15 L/min) were used as the carrier gas and reactive gas, respectively. The APP discharge power was 80 W, the jet distance was 5 mm, and the movement speed of the fabric was 0.2 m/s.…”

“…The dried fabric was then treated with plasma and cured at 120 • C, 140 • C, or 160 • C for 5 min (i.e., pad-dry-plasma-cure). The fabric samples treated with the same coating process were subsequently chlorinated at room temperature with sodium hypochlorite solution with different active chlorine contents of 0.8%, 1.0%, or 1.2%, in order to transform some of the amino groups on the pad-dry-plasma-cure treated cotton fabric into N-halamines [24][25][26][27]. After chlorination with sodium hypochlorite, these fabrics were rinsed thoroughly with deionised water in order to ensure that no free chlorine remained in the chlorinated fabric.…”

“…Experimental results reveal that CDPD treatment can provide the best antibacterial effect against S. aureus compared with CPD, CWPD, and even the "pad-dry-cure" process without plasma treatment (CD). Further studies were conducted in order to optimize the treatment conditions for CD [25], CPD [26], and CWPD [27] but the optimum condition for the CDPD process has not been reported yet. Therefore, the optimum condition for the CDPD process is investigated in this study.…”