Preparation, characterization and antibacterial properties of cellulose membrane containing N-halamine

Polyethylenimine (PEI), a type of water-soluble chain polymer containing a great number of primary, secondary and tertiary amine groups in the molecule, was used as an N-halamine precursor. It was grafted onto dialdehyde cellulose membrane (DCM) followed by chlorination to prepare a novel N-halamine antibacterial cellulose membrane (Cl-PEI-DCM). The appropriate conditions affecting the aldehyde content of DCM and the active chlorine (Cl+) content of Cl-PEI-DCM were systematically studied at oxidation, grafting and chlorination stages, respectively. The structure and properties of the samples were investigated by SEM, ATR-FTIR, XRD, XPS, light transmittance measurements and tensile tests. The stability and rechargeability of the Cl-PEI-DCM were evaluated, and its antibacterial activity was tested against S. aureus and E. coli. Results showed that the Cl+ content of the chlorinated samples was strongly dependent on the aldehyde content of DCM and PEI concentration. Under the optimum testing condition, the Cl+ content of the Cl-PEI-DCM reached 1.30wt%. The hydroxyl groups on the cellulose membrane were changed to aldehyde groups and the successful introduction of PEI and N-Cl bond were confirmed. The 1.30wt% Cl-PEI-DCM exhibited high antibacterial activity against both S. aureus and E. coli, which can completely inactivate two bacterial pathogens within 5min even after 15days of storage. Moreover, the Cl-PEI-DCM membrane displayed good stability, rechargeability, transparency and high mechanical strength. These results demonstrated that the Cl-PEI-DCM can be considered as a visualized wound dressing material or antibacterial shoe insole. [GRAPHICS]