Optical studies on thermally surface plasmon tuned Au, Ag and Au:Ag nanocomposite polymer films

Au, Ag and Au:Ag-PVA nanocomposite polymer films were prepared through simple, cost effective way. Various sizes of metal nanoparticles and bimetal nanoparticles were prepared through polyol method through thermal annealing. Polyvinyl alcohol polymer is used as a reducing and capping agent. Prepared films are different in color due to the presence of different kind and size of nanoparticles. Optical absorption studies reveal the characteristic surface plasmon absorption of Au, Ag are at 532 and 410 nm. The spectra of Au:Ag films show absorption centered at different wavelengths depending upon the concentration. Thermal annealing of films increased the size, alloy and bimetallic nature of the nanoparticles. Optical absorption nanocomposite film was analyzed using the Mie theory.

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► In this report we found concentration dependent Au:Ag alloy formation and also the bimetallic nature in polymer host.
► Thermal annealing shows tuning the surface plasmon absorption through alloying of metallic clusters.
► Apart from this the mono metallic particles show size growth when annealed.
► In polymer matrix, it is first time to show binary metallic phase through in-situ synthesis.