Study On Cellulose Fiber Antibacterial Materials With Dual Action Mechanism

The war of human being against harmful microbe such as bacteria and viruses broke out even in the early days of human civilization and has lasted for an extremely long time. At present, antibacterial materials are demanded with superior urgency for removing potentially pathogenic microorganisms. There are mainly three strategies to render materials antibacterial: adhesion resistance, contact killing, and biocide agent leaching. However, each of these antibacterial approaches has its own advantages in certain circumstances but disadvantages in other setting. In this paper, two kinds of bi-functional antibacterial materials were prepared by combining contact killing with biocide agent leaching mechanism.1. Quaternary ammonium/N-halamine-functionalized cellulose fiber was prepared by co-grafting N-halamine and quaternary ammonium salt (QAS) from cellulose fiber. The grafted fiber was characterized by fourier transform infrared spectra (FT-IR), and X-ray photoelectron spectra (XPS), thermogravimetric analysis (TGA) and scanning electron microscopy (SEM). The antibacterial activities of singly (only QAs-functionalized or only Cl+-releasing) and dual (QAs-functionalized and Cl+-releasing) functional cellulose fiber were tested against Gram-negative E. coli and Gram-positive S. aureus. The bi-functional cellulose fiber killed above99.96%E. coli and above99.99%S. aureus after contact15min. Compared to singly functionalized formulations, the bi-functional cellulose fiber exhibited excellent and rapid bactericidal performance against both E. coli and S. aureus based on dual bactericidal mechanism.2. Quaternary ammonium/silver chloride modified cellulose fiber was synthesized via graft polymerization and on-site precipitation, and was characterized by fourier transform infrared spectra (FT-IR), and X-ray diffraction (XRD), and scanning electron microscopy (SEM), and so on. The observed zone of inhibition for the immobilized AgCl nanoparticles composites indicated that the biocidal silver ions were released from the composites in aqueous. The quaternary ammonium/silver chloride modified cellulose fiber exhibited excellent antibacterial activity against gram-negative E. coli and gram-positive S. aureus. In addition, the prepared composites killed above99.83%E. coli and above99.91%S. aureus after contact60min, and showed enhanced antibacterial activity compared to that of cationic polymer grafted cellulose fiber and AgCl alone. Presumably because of the dual action bactericidal activity based on the antibacterial properties of the cationic polymer and the silver chloride nanoparticles.