Synthesis and characterization of Ag nanoparticles–polyaniline composite powder material

The chemical deposition of silver particles in polyaniline (PANI) powder has been carried out via the reduction of Ag+ ions by PANI in various concentrations of AgNO3 aqueous solutions. It is found that the rate of Ag(I) reduction and the size of the metal particles incorporated were strongly dependent on the reaction medium, the PANI redox form and the stirring method used. Homogeneous distribution of silver nanoparticles into PANI matrix was obtained at low Ag(I) concentration, PANI in emeraldine base form and short reaction time under ultrasonic stirring. The presence of silver particles dispersed into porous polyaniline structures was confirmed using X-ray diffraction, scanning electron microscopy and cavity microelectrode (CME) technique in acidic aqueous electrolyte. The electrochemical study of Ag-PANI composite by CME showed that the redox system of silver depends on the size and the distribution of metal particles incorporated into PANI.