Abstract:
This work studied on preparation of chitosan/silver/montmorillonite composite coated silk fabric. Silver colloids were prepared by chemical reduction and UV reduction methods. It was obtained that the optimum coating condition of blue silver colloid which was synthesized by a chemical reduction method using NaBH4 (AgNO3 0.2 mM) as a reducing agent on silk fabric by dipping and stirring was the weight ratio of silver colloid : silk fabric at 1:200, the coating temperature at 100 oC for 90 minutes, and the silver colloid was adjusted pH value to 5. The silk fabric coated by chitosan and silver showed an excellent antibacterial against S. aureus, but after coating with the montmorillonite, the antibacterial activity was decreased while the flame-retardant property of silk was improved. For UV reduction method, the optimum irradiation time of AgNO3 with chitosan solution was 2 hours. The UV-vis absorbance spectrum of the colloids showed the Localized surface plasmon resonance (LSPR) indicating the formation of silver nano particles after an UV irradiation. Montmorillonite was added in the chitosan/silver solution and then the chitosan/silver/montmorillonite composite was coated on silk fabric by pad method. The results showed that silver nano particles were observed on the surface of silk fabrics confirmed by microstructural and elemental analysis. The antibacterial and flame-retardant properties of chitosan/silver and chitosan/silver/montmorillonite composites coated fabrics were similar to that of the chemical reduction method.