Antibacterial functionalization of cotton and polyester fabrics with a finishing agent based on silver-doped calcium phosphate powders

Textiles are suitable materials for the growth of pathogenic microorganisms. Therefore, various antibacterial finishes have already been developed for textile products. In this work an antibacterial finishing agent containing calcium phosphate-based silver-doped powder was developed for the functionalization of textiles and applied to 100% cotton and 100% polyester knitted fabric samples. Firstly, silver-doped antibacterial powder was synthesized by using a wet chemical method. A size reduction process was applied for reducing the particle size of the powder from micron size to submicron scale. The aqueous dispersion was stabilized by coating the powder surfaces with polyethylene glycol. In order to obtain laundering durability, an aqueous emulsion of an acrylic copolymer was added to the antibacterial solution. The resultant product was applied to all fabric samples by a conventional pad-dry-cure method. The treated fabrics were washed 20 times and the antibacterial efficiency was evaluated after each 10 laundry cycles according to the JIS-L 1902:2002 method against Gram (-) E. coli bacteria. To see the effect of antibacterial finishing on the physical properties of fabrics, the bursting strength, air permeability and color efficiency of the treated and untreated samples were measured and compared. It was found that the antibacterial solution did not affect significantly the bursting strength and color efficiency values of the fabrics, while air permeability was decreased. On the other hand, treated fabric samples preserved their strong antibacterial activities against E. coli after 20 laundry cycles.