A Facile and Controllable Approach for Surface Modification of Wool by Micro-dissolution

Abstract

Most modifications of wool focused on its surface due to the existence of the cuticle scales. For instance, chlorination, oxidation and protease treatments were used to break down or remove the scales. However, these modifications usually severely damaged the internal structure of wool. In this paper, a novel approach based on surface micro-dissolution was employed to modify the surface of wool to minimize the internal damage of wool, and improve the surface-related properties of wool. The micro-dissolution system used NaHSO3/urea to dissolve the scale layer of wool. After being micro-dissolved with NaHSO3/urea system, scanning electron microscope (SEM), X-ray photoelectron spectroscopy (XPS), fluorescence microscopy, Fourier transform infrared spectroscopy (FTIR), and the Allworden reaction were utilized to characterize the treated wool. Furthermore, felting shrinkage, strength loss and wettability of the treated wool were determined. The results showed that NaHSO3/urea system could dissolve the scale layer from outside to inside. The fluorescence microscopic images further indicated that low concentration of NaHSO3/urea system can dissolve the surface of wool without the serious damage of internal structure. Moreover, the micro-dissolution system can be controlled to dissolve the scale layer on the surface of wool slightly by adjusting the reaction conditions. The presented method is simple, easy to operate, and economical, thereby can open up new directions for the surface modification of wool.