Crosslinking chitosan into H3PO4/HNO3–NANO2 oxidized cellulose fabrics as antibacterial-finished material

The primary hydroxyl groups on C6 position in glucose units of cellulose with H3PO4/HNO3–NaNO2 mediated oxidation produced monocarboxy cellulose and binding sites, subsequent amide reaction with chitosan solution to obtain chitosan crosslinked cotton fabrics. Scanning electron microscope and FT-IR spectroscopy were used to detect the fiber morphology and chemical bonding between chitosan and oxidized cellulose, respectively. The influences of H3PO4/HNO3–NaNO2 oxidation and chitosan treatment on physical properties of cotton fabrics were examined by determining carboxyl content, weight loss and mechanical properties of fabrics, as well as chitosan content in the composite fabrics. Antibacterial performance of chitosan–cellulose fabrics against Escherichia coli and Staphylococcus aureus was evaluated. As a result, chitosan was bonded into cotton fiber via the amido bond of CN formed between amino groups of chitosan and carboxyl groups on oxidized cellulose, and these resultant chitosan–cotton fabrics showed high antimicrobial activity and excellent antibacterial washing durability.