Plasma-Aided Antimicrobial and Insect Repellant Finishing of Cotton

Abstract

This research aimed to impart antimicrobial and insect repelling finishes to cotton fabrics using atmospheric pressure plasma-aided graft copolymerization of active monomers. The process consists of multiple steps; first, surface activation of fabric samples via atmospheric pressure plasma, followed by polymerization reaction of glycidyl methacrylate (GMA). Following GMA grafting, antimicrobial agents (β-cyclodextrin or quaternary ammonium chitosan derivative, HTCC) are reacted with grafted GMA epoxide groups to produce cotton⁄GMA⁄antimicrobial agent. Samples grafted with β-cyclodextrin are reacted with insect repelling agents (such as extracts of citronella, sweet basil, jasmine) as inclusion into the cavities of β-cyclodextrin.

Samples were exposed to plasma, which has 99% helium and 1% oxygen, for times up to 2 minutes with incremental exposure times to determine the optimal exposure to plasma. Samples were conditioned in an environmental chamber prior to plasma exposure. Weight changes were recorded to determine the percent add-on in each step. Samples were analyzed post plasma exposure and inclusion of the active agents using Fourier Transform Infrared Spectroscopy (FTIR) and Scanning Electron Microscopy (SEM). Standard washing test was conducted to determine the effectiveness of grafting after washing. Analysis is repeated after storing the samples for several weeks to determine any aging effects.

Antimicrobial and insect repellency assays were conducted on treated samples and compared to control. Treated samples have shown excellent antimicrobial and insect repelling efficiency.