Improved antimicrobial activity of polypropylene and cotton nonwoven fabrics by surface treatment and modification with chitosan

Nonwoven polypropylene and cotton fabrics were subjected to plasma pretreatment followed by flash evaporation and radiation crosslinking acrylate polymer coating, which is based on a vacuum deposition, solvent free, process that produces high quality, uniform fabrics with various thicknesses (0.05-5.0 pm). These treated fabrics were then dipped into chitosan, carboxymethyl chitosan, and carboxymethyl chitin solution. These polysaccharides form strong complexes with the modified surface. The antimicrobial activity of these treated samples was then evaluated for their antifungal and antibacterial properties. The antifungal activity for Fusarium oxysporum f. sp. lycopersici, Verticillium albo-atrum, and Alternaria solani (A. alternata) were examined by the disc plate method. The antibacterial activities of the modified fabrics against Clavibacter michiganensis and Pseudomonas solanaceraum were also examined by the viable cell counting method. The inhibition zone of the chitosan covered samples has increased by a factor of 2-3.1 over the original pretreated samples. The chitosan-modified fabrics showed a good antibacterial activity in killing almost 10(5) cells/mL within 18-23 h. (C) 2008 Wiley Periodicals, Inc.