STRUCTURAL, OPTICAL AND ELECTRICALCHARACTERIZATION OF POLYANILINE/ SILVER NANOCOMPOSITES

Jayasudha S, Priya L, K.T. Vasudevan

Abstract: Nanocomposites of conducting polyaniline with Silver (PAni/Ag) have been synthesized by in-situ polymerization of aniline monomer using ammonium persulphate as an oxidizing agent. The weight percentage of silver varied from 3% to 25%. The formation of PAni/Ag composites was assessed by X-Ray Diffraction (XRD), Field Emission Scanning Electron Microscope (FESEM) and UV-Vis spectroscopy. The broadening of sharp peaks in the XRD pattern indicates the presence of nano phase of Ag. The crystallite size of PAni/Ag nanocomposite from XRD is found to be ~17.5nm. The FESEM image shows a nanoparticular structure of silver and it is also seen that the Ag nanoparticles are well dispersed in the polyaniline matrix. UV-Vis spectrogram of composites shows three peaks at ~240nm, 450 nm and 700 nm respectively in addition to ~198 and ~324 nm peak of Pure PAni. The peak around 450 nm confirms the presence of radical cation or polaron transition. The peak around 700 nm is the characteristic peak of PAni Emeraldine base. The peak around ~240 nm could be assigned to the characteristic absorption of small metallic Ag cluster. The graph of h?Vs (ah?)2 was also plotted. The PL spectrum of PAni/Ag was excited with an excitation wavelength of 320 nm. Two peaks are observed at a wavelength of ~370nm and 600 nm. The DC conductivity of Pure PAni and its composites have been measured in the temperature range from 25°C to 150 °C. The DC electrical study of PAni/Ag nanocomposite clearly indicates that the Ag nanoparticles increase the electrical conductivity of polyaniline nanocomposites as compared to polyaniline.

Keywords: XRD, Photoluminescence, Polyaniline, Differential scanning calorimetry

DOI: https://doi.org/10.15623/ijret.2016.0516067