INVESTIGATION ON THE EFFECTS OF ANTIBACTERIAL FINISHES ON DYED COTTON KNITTED FABRICS

The main objective of the research was to obtain antibacterial and antifungal effects in case of dyed cotton knitted fabrics. In addition to antibacterial properties, other effects of the antibacterial treatment on the dyed fabrics were investigated: the amount of metal bonded on fibre, the chromatic parameters, and the dye fastness. During the finishing process, the samples were subjected to several treatments, as: preparation for dyeing, pre-treatment with chitosan, dyeing with Direct Green 26 dye. In order to provide dyed materials with antibacterial properties, the samples have been treated, in different conditions, with different concentrations of silver nitrate (AgNO3) and zinc sulphate (ZnSO4) solutions. After the finishing process, the samples were tested against several microbial organisms: bacteria (gram positive and gram negative) and fungi. Due to their antimicrobial activity, both chitosan and metal salts have been taken into consideration in the research. Fourier transform infrared–attenuated total reflectance spectroscopy (FTIR-ATR) technique was used to study the fiber changes as a result of treatment with chitosan, dyeing stuff and metallic salts.