Chiang Mai Journal of Science

Synthesis of colloidal silver nanoparticle by using peel extracts of Ipomoea batatas L., its deposition on polyester cloths, and the modification with hexadecyltrimethoxysilane (HDTMS) have been conducted in this work. The silver nanoparticles were characterized by using Uv-Vis spectrophotometer, functional groups of unmodified polyester and those of modified polyester were characterized by ATR-FTIR spectrophotometer, surface images of polyester were observed by Scanning Electron Microscopy tool, antibacterial activity of unmodified polyester cloth and modified polyester against Staphylococcus aureus and Escherichia coli were determined with a diffusion method, and hydrophobicity of polyester was measured by using a sessile drop method. Silver nanoparticles were successfully produced using peel extracts of Ipomoea batatas L as indicated by the absorption peaks at 436 nm. SEM images confirm that the silver nanoparticles coat onto polyester cloths. Modification with nanoparticle and HDTMS do not affect the functional groups of polyester. The polyester fabric with the addition of HDTMS compound and silver nanoparticles showed the largest contact angle and the antibacterial activity to inhibit Staphylococcus aureus. Samples of polyester - HDTMS - silver nanoparticle show the highest antibacterial activity against S. aureus with a strength 1.4 times greater than unmodified polyester. There is a difference in the antibacterial activity of the polyester among the unmodified polyester and the modified polyester fabric at different incubation times inhibiting the growth of Escherichia coli and Staphylococcus aureus. Each sample ofthe unmodified polyester and the modified polyester fabric shows the same ability to inhibit the growth of Staphylococcus aureus and Escherichia coli.