Washable antibacterial cellulose fabric with improved mechanical strength through constructing an adhesive polymer coating by nano glue

The conventional antimicrobial treatment process for cellulose based fabrics such as cotton fabrics faces significant challenges, including suboptimal durability of antimicrobial coatings and degraded mechanical properties of textiles after treatment. Herein, an antimicrobial adhesive of silver and copper composite nanoparticles (AgCuNPs) was prepared by simultaneous in-situ reduction of Ag + and Cu 2+ in the presence of waterborne polyurethane (WPU). The synthesized AgCuNP glue exhibited an average particle size as low as 2.1 nm, a zeta potential as high as −64.8 mV at the optimum mass ratio of WPU to AgCu of 9:1, and high adhesion strength to cellulose, which ensured good wash resistance of AgCuNPs. WPU was found to form a closed film on the surface of cotton fibers, thereby providing AgCuNPs with adequate adhesion strength. In addition, AgCuNP-coated cotton fabric as low as 100 mg/kg showed ~100 % antibacterial rates against Escherichia coli and Staphylococcus aureus after 50 washes, indicating excellent washability. Finally, the 100 mg/kg of coated cotton fabric showed good resistance to abrasion and sunlight exposure, good biocompatibility, and enhanced mechanical properties. The tensile strength and hydrophobicity of AgCuNP-coated cotton fabric were improved after treatment, probably because the penetration of WPU into the yarn improved fiber cohesion.