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Silver nanoparticles/polystyrene nanocomposites were prepared via casting the solution of polystyrene in a mixture of carbon tetrachloride and acetone containing silver nanoparticles. Colloidal silver nanoparticles in acetone were synthesized by pulsed laser ablation of pure bulk silver. Nd: YAG laser at wavelength of 1064 nm, 130 mJ/pulse energy, 10 ns duration and reparation rate of 10 Hz has been employed to synthesis of nano silvers. Casting the solution of nano silver in a mixture of carbon tetrachloride, acetone and polystyrene results in a transparent polymeric sheet in light yellow color. The Ag/PS nanocomposites were characterized by Scanning Electron Microscopy (SEM), X-ray photoelectron spectroscopy (XPS), UV-VIS spectroscopy and FTIR spectroscopy. We compared the X-ray photoelectron spectra of pure PS with Ag/PS nanocomposites. The interfacial interaction between the silver nanoparticles and PS was also investigated with FTIR spectra. In this study, we also investigated the antimicrobial activity of silver nanocomposites against Escherichia coli as a model for Gram negative bacteria. Bacteriological tests were performed in Luria bertani (LB) medium on solid agar plates. These nanocomposites were shown to be an effective bactericide. Antibacterial tests were performed against the gram negative bacterium E. coli, on LB agar plates containing different concentrations of nanoparticles. Our results showed at all these concentrations, the nanoparticles caused a growth delay of E. coli, increasing the concentration of nanoparticles increased this growth delay. |