High-strength hydrophilic N-halamines chitosan and cellulose nanofibers membranes with repeated bactericidal properties.

Direct addition of disinfectants and membrane separation techniques have been common methods to address microbial contamination in water. However, disinfectants may generate toxic by-products, and even minor damage or biofilm formation on filtration membranes can lead to a heightened risk of microbial contamination. Consequently, how to quickly and safely disinfect microbial contaminated water sources remains a huge challenge. In this study, the high-strength broad-spectrum antibacterial CNF/CS composite membrane was fabricated by utilizing cellulose nanofibers (CNF) to reinforce the structure of chitosan (CS). The resulting CNF/CS composite membrane exhibits an impressive tensile strength of 148 MPa and boasts an active chlorine content of 5.29 %. Notably, even after undergoing 50 washing cycles and 10 repeated chlorination procedures, the structural integrity and high active chlorine content of the composite membrane remain preserved, validating its exceptional strength, stability, and chlorine rechargeability. Additionally, the CNF/CS antibacterial materials demonstrate remarkable attributes in terms of rapid sterilization, sustained and consistent release of active chlorine, and efficient inhibition of biofilm formation, demonstrating great potential in efficient, green, and safe sterilization. [Display omitted] • CS is used as N-haloamine antibacterial substance. • CNF and CS form a lamellar structure to prevent the destruction of chitosan structure by chlorination. • The active chlorine content of Chlorinated CNF-3/CS-1 can reach 5.29 wt% • The CNF-3/CS-1 still maintains its integrity and high active chlorine content after 50 washing and 10 repeated chlorination. • Chlorinated CNF/CS membranes kill Escherichia coli and Staphylococcus aureus within 60 s. [ABSTRACT FROM AUTHOR]