Utilizing cellulase as a hydrogen peroxide stabilizer to combine the biopolishing and bleaching procedures of cotton cellulose in one bath

In this research, the stabilization effect of cellulase on the decomposition of hydrogen peroxide was investigated for the first time. It was concluded that, regardless of the decomposition mechanism, the cellulase protein could contribute significantly to peroxide stability. This effect stems from the formation of molecular hydrogen bonding between peroxide and cellulase protein or direct sequestering of free metal ions by amino acids in cellulase. Furthermore, based on this stability, a combined biopolishing and peroxide bleaching protocol was developed to improve cotton quality more efficiently. Afterwards, physicochemical properties such as the weight and strength loss, water absorbency, and carbonyl and carboxyl group content of treated cotton cellulose were measured to show the feasibility of the new method. Fourier-transform infrared (FT-IR) and X-ray diffraction (XRD) analyses indicated that the crystallinity index of cotton was increased due to the preferential hydrolysis of amorphous cellulose by cellulase.