Preparation of Antibacterial Silk and Analysis of Interface Formation Mechanism

Nano-Ag-loaded SiO2 antibacterial agent (Ag/SiO2) was prepared by a chemical reduction method and served as a modifier to endow silk fabric with antibacterial activity. Impregnated antibacterial silk (I-silk) and grafted antibacterial silk (G-silk) were obtained by dipping method and grafting with coupling agent KH550, respectively. The morphologies and valence-bond structures were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), and Fourier transform infrared spectroscopy (FTIR). The washing fastness and antibacterial performance of G-silk were detected by the washing test and oscillation flask method. The results show that the chemical structure of G-silk changed in comparison with that of natural silk. The antibacterial rates of G-silk against E. coli and S. aureus were 96.5% and 92.8%, respectively. And it was still over 80% even after being washed for 30 times, suggesting good wash fastness and long-acting antibacterial activity.