Simultaneous Enhancement of the Affinity for Acid Dyeing and Antibacterial Performance via Cationic Pre-treatment of Cotton

As known cotton can’t be dyed with acid dye due to the anionic charge similarity of surface. Hence, the present work studied the enhancement in dyeability and the antimicrobial activity of cotton fabrics after cationization with gemini cationic agent (GCA). Firstly, GCA was freshly prepared and loaded onto cotton fabrics to obtain cationic cotton. Subsequently, GCA-cotton was dyed with blue acid dye and red reactive dye. The colorimetric data revealed that the coloration of cotton with acid dye was significantly improved after cationization and the color strength was largely increased from 0.18 to 6.96 at 60 °C. This is corresponded to the electrostatic interactions between the anionic acid dye and cationic cotton and consequently deeper blue color obtained. The enhancement in acid dyeing is quite higher compared to that of reactive dyeing. The cationization didn’t significantly effect on the fastness properties, while the all tested fabrics showed generally good fastness properties. Due to cationization, the estimated microbial reduction of dyed samples was largely increased from 19-33% and 15-26% to 72-78% and 68-70% for S. Aureus and E. Coli, respectively. Moreover, the maximum strain was improved after cationization attributing to the crosslinking effect of cationic agent with cotton.