Enhanced wettability and moisture retention of cotton fabrics coated with self-suspended chitosan derivative

From the industrial viewpoint, it would be desirable to use neutral aqueous solution when applying chitosan coatings for textile treatment. However, in most cases, chitosan only dissolves in acid solvents. In this work, a self-suspended chitosan derivative with liquid-like behavior was prepared by decorating chitosan with a quaternary ammonium salt followed by ion exchange with nonylphenol polyoxyethylene ether sodium sulfate (NPES). The chitosan derivative with higher NPES content dissolved in neutral aqueous solution, and even exhibited liquid-like viscous behavior without water at room temperature. The morphology, structure, composition, and rheological behavior of the chitosan derivative were systematically characterized using various methods. It was found that incorporation of NPES into the chitosan structure could greatly enhance its dispersion, while the modulus and viscosity of the derivative gradually decreased with increasing temperature. Moreover, the novel chitosan derivative not only directly coated cotton fabric via hydrogen-bonding interaction without removing water but also improved the long-term wettability and moisture retention because of the dual-layer ion structure of the chitosan derivative. The results showed that cotton fabrics coated with such chitosan derivatives could be developed as wound dressing materials in future work.