An Effective Modification for Enhancing Bio-functionality and Coloration of Silk Fabrics with Chitosan/Alpha-Lipoic Acid Conjugates

Inorder to improve the biological functionality and dyeability of silk fabrics, chitosan/alpha-lipoic acid (CS/LA) conjugates were used to modify silk fabrics via dip-padding and hot-pressing methods. Structural and morphological characterization of the as-prepared silk fabrics was performed by various testing techniques. The results showed that the incorporation of CS/LA conjugates with silk fiber significantly improved the antioxidant properties, crease resistance, ultraviolet protection, and dyeability of silk fiber. The effect of different dyeing parameters on dyeing properties was investigated. When dyed with curcumin and weak acid red B at low temperatures without any additional agent, the modified silk fabric could achieve a higher color depth (K/S) and dye exhaustion than unmodified ones. The adsorption behaviors of the modified silk fabrics on curcumin and weak acid red B followed the Langmuir isotherm model and the quasi-second-order kinetic model at dyeing temperature of 40 °C without pH adjustment. In addition, the dyed modified silk fabric with curcumin still maintained excellent antioxidation activity even after 15 times of washing circles and high color fastness. This study presents a viable approach to achieve healthcare function and low-temperature dyeing of silk textile products, which is also in line with the development goal of the sustainable process for textile dyeing and finishing.