Thermally responsive copper alginate/nano ZnO/quaternary ammonium chitosan triple antimicrobial fiber

Abstract

Smart and controllable antibacterial fabrics have enormous potential in the textile, medical, and healthcare fields. In this study, nano zinc oxide (ZnO) was synthesized in situ in sodium alginate (Alg) solution, and the above-mentioned solution was combined with quaternary ammonium chitosan (QAC) to form a polyelectrolyte spinning solution. A composite antimicrobial fiber with thermally responsive properties was created by wet spinning through CuCl2 coagulation bath crosslinking and in-situ synthesis of CuS on the fiber surface. Benefitting from the mixed-solubility synergistic effect of Alg and QAC, the mechanical properties of composite fiber materials were greatly improved. The tensile strength of the fiber was 58 ± 1.5 MPa, while the fiber material maintained good biocompatibility, moisture absorption, air permeability, and antibacterial properties. Adding a CuS layer gave the composite fibers photothermal response-ability and further promoted the controllable antibacterial properties of the materials. The maximum rings of inhibition of the copper alginate/nano ZnO/quaternary ammonium chitosan/ copper sulphide (CAlg/ZnO/QAC/CuS) composite fiber against S. aureus, E. coli and P. aeruginosa were 2.9 mm, 2.5 mm and 2.2 mm respectively. This was attributed to the synergistic effect of the inorganic and organic antimicrobial agents of nano ZnO and QAC component as well as the thermal stimulation response of CuS. These characteristics of the smart responsive composite fibers indicate their potential applications in medical dressings, special textiles, and healthcare materials.