Electro-optical properties of polyaniline multilayers thin film containing in situ silver nanoparticles

Abstract

Polyaniline multilayer thin films were fabricated by an alternated layer-by-layer deposition of polyaniline-polystyrene sulfonate complex (PANI-PSS) and Poly (diallyldimethylammonium chloride) (PDADMAC). PANI-PSS was synthesized through an interfacial polymerization of aniline by using PSS as a template. The in situ synthesis of silver nanoparticles was achieved by loading silver nitrate into the film followed by sodium borohydride reduction. The films with silver showed a difference in optical sensing properties and an increasing of conductivity of the film. The film became more metallic and more shiny after multiple silver reduction. The optical and electrical properties of the film were analyzed by Ultraviolet-Visible spectroscopy (UV-Vis) and 4-points probe measurement. The surface and bulk morphology were observed by scanning electron microscope (SEM). The thickness of the film was measured by atomic force microscopy (AFM). Fourier transform infrared spectroscopy (FTIR) was used to confirm the chemical structure of the film and X-ray diffraction (XRD) was used to characterize silver.