Antibacterial efficacy of poly(hexamethylene biguanide) immobilized on chitosan/dye-modified nanofiber membranes.

The objective of this study was to develop a novel electrospun polyacrylonitrile (PAN) nanofiber membrane with enhanced antibacterial property. During the synthesis process, the PAN nanofiber membrane was first subjected to alkaline hydrolysis treatment and the treated membrane was subsequently grafted with chitosan (CS) to obtain CS-modified nanofiber membrane (P-COOH-CS). The modified membrane was then coupled with different dye molecules to form P-COOH-CS-Dye membranes. Lastly, poly(hexamethylene biguanide) hydrochloride (PHMB) was immobilized on the modified membrane to produce P-COOH-CS-Dye-PHMB. Physical characterization study was conducted on all the synthesized nanofiber membrane. The antibacterial efficacy of the modified nanofiber membranes with different synthesis conditions were evaluated systematically. Under the optimum synthesis condition, it was found that the P-COOH-CS-Dye-PHMB was highly effective in disinfecting high concentration of Escherichia coli, with an antibacterial efficacy of approximately 100%. Additionally, the P-COOH-CS-Dye-PHMB exhibited outstanding wash durability as its antibacterial efficacy was only reduced in the range of 5%-7% even after 5 repeated cycles of treatment. Overall, the experimental results of this study suggested that the P-COOH-CS-Dye-PHMB is a promising antibacterial nanofiber membrane that can be adopted in the food, pharmaceutical, and textile industries.