Morphological Observation of Partially Carboxymethylated Cotton Treated by Cellulase

Abstract

In our previous paper, cotton fabrics which had been modified by carboxymethylation so as to have the degree of substitution of 0.02~0.16 were treated with a commercial cellulase preparation. The modification by carboxymethylation for cotton fabrics apparently inhibited weight loss activity and saccharification activity of cellulase. In this study, by scanning electron microscopy, we observed morphological changes of fiber surface of modified cotton fabrics treated with a commercial cellulase preparation. For unmodified cotton fabrics, deep bias cracks were produced and clear fibrillar layers appeared on the fiber surface by synergistic reaction of cellulase components. On the other hand, for cotton fabrics modified by carboxymethylation, we observed inhibition of catalytic reaction of some cellulase components, as a result of no deep cracks and no appearance of fibril layers on fibers. In addition, we confirmed, by measurements of FT-IR spectra and K/S values of fabrics dyed with a basic dye, that carboxymethyl groups in modified cotton fabrics remained even after treatment with cellulase. From these results, it is suggested that the change in the activity of each cellulase component on modified cotton can affect the synergistic action of cellulases, and consequently the morphology of fiber surface of modified cotton changes compared with unmodified cotton.