International Journal of Scientific and Research Publications, Volume 6, Issue 9, September 2016 21 ISSN 2250-3153 www.ijsrp.org OPTICAL BAND GAP STUDIES OF POLYPYRROLE DOPED WITH CUZnFe2O4 NANO PARTICLES *V.S. Shanthala 1 , S.N. Shobha Devi 2 , M. V. Murugendrappa 3 1 The Oxford College of Science,Department of Physics, Bangalore, India 1 Department of Research and studies in Physics, Tumkur University, Tumkur, India shanthalasastry@gmail.com cell-9880820145 2 Department of Physics, BMS College for Women, Bangalore, India drshobhasn@gmail.com cell-9845914272 3 Department of Physics, BMS College of Engineering, Bangalore, India murugeshbms@gmail.com cell-9972727000 *corresponding Author : shanthalasastry@gmail.com ABSTRACT- Polypyrrole/CuZnFe 2 O 4 nanocomposites were synthesized by in-situ polymerization with Ammonium persulphate as an oxidising agent. Optical band gap of chemically synthesized polypyrrole and Polypyrrole-CuZnFe 2 O 4 (10% - 50%) nanocomposites have been studied at room temperature and normal pressure. Energy band gap of these materials are determined by UV-VIS absorption spectra in the wavelength range 264nm–1936nm by spectrophotometer. In this work the experimental results obtained from the UV-VIS spectra are reported for nanocomposites of different wt percentages (10% -50%.). Characteristic peak around 800 nm was observed in all the nanocomposites confirming the formation of polypyrrole. The work highlights the optical properties of these polymer nanocomposites for making them a suitable candidate for optoelectronic devices Keywords: Polypyrrole, band gap, absorption spectra, nanocomposite, wavelength. I. INTRODUCTION In recent years Polymer nanocomposites have become one of the most extensively studied materials all over the world due to their unusual properties. Owing to their unusual combination of properties they have wide range of applications in various fields such as sensors, electronic devices, memory devices, lithium batteries, energy storage, microwave absorbers, electromagnetic shielding, optoelectronic devices etc.; [1-2]. In a number of applications the control of band gap is essential, be it for light emitting diodes (LED) transparency in the visible region combined with high electrical conductivity etc.[3]. The optical band gap is the characteristic of the materials and it depends on the crystallinity and stoichiometry of the material. UV–VIS diffuse reflectance spectroscopy is one of the most employed characterization technique that describes the electronic behavior present in the structure of the solid. Through the absorption spectra, UV–VIS spectroscopy gives information about the electronic transitions of the different orbitals of a solid. The optical excitation of the electrons from the valence band to the conduction band is evidenced by an increase in the absorbance at a given wavelength, which corresponds to the band gap energy.