Abstract:
This study aimed at the synthesis of colorful silver colloids and finding the optimal condition for coloring and enhancing the antibacterial properties of the silk yarn. The effect of TiO2 adding on properties of the silk yarns was also investigated. Silver nanoparticles were synthesized by a chemical reduction method using NaBH4 as a reducing agent, H2O2 as an oxidizing agent, and trisodium citrate as a protecting agent of {111} facets of nanoparticles. Adding the different amounts of NaBH4 provided colorful silver colloids due to the different morphologies of silver nanoparticles. It was found that the optimal condition for coloring silk yarns was achieved by immersing silk yarn into a silver colloid, which was adjusted the pH value to 5 and added TiO2 (P25), with a weight ratio of silver colloid to silk yarn to TiO2 at 200:1:0.05 for 45 minutes at room temperature. The colored silk yarns were rinsed with deionized water and dried at 60°C for 4 hours. Then, the obtained silk yarns, which were coated by silver and TiO2 nanoparticles, were immersed into the polyacrylic binder solution with 5wt% of the weight of silk yarns for 20 minutes at 30 40 °C and cured at 130 °C for 3 minutes. The results showed that the coloration of the silk yarn with silver and TiO2 nanoparticles could be achieved at room temperature. Moreover, the obtained silk yarns exhibited strong antibacterial activities against E. coli. and S. aureus, and an excellent UV protection property. It was demonstrated that coating with a polyacrylic binder could improve the colorfastness to washing by fresh and soapy water of the colored silk yarn.