Simultaneous Coloration and Antibacterial Modification of Wool Fabric with Chitosan Oligosaccharide via Maillard Reaction

Chitosan oligosaccharide (COS) was utilized to simultaneously dye and functionally modify wool fabrics with antibacterial activity via Maillard reaction in this work. Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and infrared spectrometer (IR) were used to demonstrate the reaction between COS and wool keratin. The results verified the formation of new keratin-COS conjugates with higher molecular weight. Time, pH and temperature of the reaction had a great effect on the color strength (K/S) of the dyed wool fabrics caused by maillard browning. The affinity of COS to the wool could be improved significantly and the color depth of the dyed fabric increased accordingly when the fabrics were pretreated with different agents (H2O2, mercaptoethanol or protease). In the meantime, the dyed fabrics showed promising antibacterial capacity against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) in addition to good color fastness.