A study of metal oxide on antimicrobial effect of plasma pre-treated cotton fabric

Cotton, a natural fibre that consists of cellulose, is highly popular because it is sweat-absorbing and comfortable to wear. However, cotton fabrics provide an excellent environment for microorganisms to grow, owing to their ability to retain moisture. Therefore, numerous chemicals have been used to enhance anti-microbial activity of cotton textiles. This paper reports results of use of silver oxide (Ag₂O) or zinc oxide (ZnO) as a catalyst in the antimicrobial formulation (halogenated phenoxy compound (Microfresh, MF)) and a binder (Microban, MB) for improved treatment of cotton fabrics and minimisation of side effects of the treatment. In addition, from the morphological study, plasma technology was employed to roughen the surface of the materials to improve loading of metal oxides on the surface. Moreover, the characteristic infra-red bands related to plasma-treated cotton produced results different from untreated fabric, implying plasma treatment can improve hydrophilicity of the fabric. Mechanical strength of the specimens was also increased by plasma treatment. Meanwhile, the research showed that the control fabric slightly inhibited the growth of S. aureus because of the bleach residues on fabric surface. On the other hand, anti-bacterial activity of MF-MB-treated specimen, especially in the presence of metal oxide catalyst, was enhanced, providing a slightly larger zone of inhibition. Moreover, plasma gas contains reactive oxygen species that can enter the cell, eventually causing its death. The hydrophilic nature of carbonyl groups present in oxygen plasma pre-treated specimens also increased the anti-microbial activity after treatment with MF-MB.