Fabrication of flower-like Ag/lignin composites and application in antibacterial fabrics

The bacterial infection and its transmission pose a great threat to life and health, which leads to the urgent development of efficient and broad-spectrum antibacterial agents. Herein, Ag/lignin layered nanoflower (Ag/EHL-CM-0.05) was synthesized by using biomass lignin as reducing and capping agents and silver nitrate as precursor. The study showed that the size distribution of Ag NPs was uniform distribution and about 20-40 nm. The crystal surface of Ag NPs was Ag (111) surface. The minimum inhibitory concentration of Ag/EHL-CM-0.05 against E. coli and S. aureus was all 7.8 μg/mL, which was the lowest of other Ag/lignin antibacterial materials and reached a level nearly as polycationic antibacterial agents. The antibacterial mechanism suggested that Ag/EHL-CM-0.05 could release OH and Ag⁺, which could cause bacterial death. Finally, Ag/EHL-CM-0.05 was sprayed onto the viscose fabrics by liquid-phase spray deposition method. It was found that the inhibition zone diameter of modified viscose fabrics against E. coli and S. aureus only dropped about 0.16 cm on average after friction treatment and 0.32 cm on average after washing treatment. This work provides a new idea for the design and synthesize of efficient, broad-spectrum, and bio-compatible antibacterial agents, which has important social, economic, and environmental significance.