Laccase-mediated dye-free coloration of wool fabric

Abstract

In this study, an investigation on a novel coloring technique, based on laccase-mediated radical coupling of amino acidmolecules of wool fibres, has been carried out. Firstly, the influence of temperature, incubation time, and pH on the K/Svalue and hue angle (h) of the colored wool fabrics is studied. Analysis of levelness of coloration, wash fastness, rubfastness, and UV-protection factor of the colored wool fabrics has been done. Then, the surface morphology and structure ofthe wool fibres are analyzed by scanning electron microscopy (SEM) and Fourier transform Infrared spectroscopy (FTIR).The enzymatic coloration processes are carried out in an acetate-sodium acetate buffer medium (pH 5) at 50 C for 24 h andthe colored wool fabrics show good color fastness and uniformity. The results obtained are as per the requirements of textilecolor fastness. SEM study shows that no particles are adhered to the surface of the wool fibres. The results of FTIR andultraviolet-visible spectroscopy show that the obvious oxidation coupling reactions take place between the molecules in thepolypeptide chains of the wool.