Cotton devours bug and dyes
doi:10.1038/nindia.2011.171 Published online 29 November 2011
Researchers have produced a new type of modified cotton fabric by coating cotton with a polymer and zinc oxide nanoparticles. The modified fabric has the ability to absorb dyes and inhibit bacterial growth, and may therefore be useful as an infection-fighting cloth.
Cotton does not completely absorb dyes during the dyeing process. In addition, the bond between cotton and the dyes is often destroyed shortly after formation. Modifying cotton fabric using organic compounds such as carboxymethyl cellulose and sodium benzoylthioglycollate only improves the dye uptake. To deal with microbial infection in the healthcare and food industries, it would be beneficial for cotton fabric to possess antibacterial properties.
The researchers modified cotton fabric using poly-N-vinyl-2-pyrrolidone (PVP) polymers and zinc oxide nanoparticles, which are known to exert antibacterial properties. They then compared the ability of unmodified cotton, PVP-modified and PVP/ZnO-nanoparticle-modified cotton to absorb dyes (Reactive Red M5B, Yellow MXR and Blue MXR) and stop the growth of Staphylococcus aureus and Escherechia coli.
The modified fabrics exhibited better dye uptake than their unmodified counterpart because PVP acted as an adhesive agent between the dye and the cotton fibre. The unmodified fabric exhibited no antibacterial activity. The PVP/ZnO-nanoparticle-modified fabric showed better antibacterial activity than the PVP-modified fabric. PVP inhibits bacterial growth, while ZnO nanoparticles damage bacterial membranes.
The researchers say that these types of cotton fabrics could be used as bandages, surgical cloths and sportswear.
- Selvam, S. et al. Functionalization of cotton fabric with PVP/ZnO nanoparticles for improved reactive dyeability and antibacterial activity. Carbohydr. Polymer. 87, 1419-1429 (2012) | Article |