Coloration and Functionalization of Mulberry Silk\nFabrics with Laccase-Catalyzed Oxidation Products of Catechin and\nGallic Acid

In\nthis work, a simultaneous coloration and functionalization process\nof laccase-catalyzed oxidation products (LCOPs) of catechin and gallic\nacid on silk fabrics was developed. The progress of the polymerization\nreaction leading to the formation of the polymerized product was monitored\nby ultraviolet–visible (UV–vis) spectroscopy. The color\ndepth of the dyed fabrics depended on the pH of the dye bath and the\ntemperature of the treatment conditions. The silk fabric dyed with\nLCOPs of catechin and gallic acid yielded maximum color strength at\n50 °C (<i>K</i>/<i>S</i> = 27.53, and 24.87)\nand at pH 5 (<i>K</i>/<i>S</i> = 20.376 and 28.009,\nrespectively) for 60 min. The dyed silk fabrics exhibited good UV\nprotection properties with ultraviolet protection factor (UPF) values\nof 57.36 ± 5.59 and 54.53 ± 4.79, respectively, using alum\nmordant. The products of the laccase-catalyzed reaction of catechin\nand gallic acid had the potential to serve as colorants and offered\nan environmentally friendly approach for dyeing within the textile\nindustry.