Temperature dependent studies of electric and dielectric properties of p olythiophene based nano composite

The fabrication, characterization, electric, dielectric and ac conductivity measurement of polythiophene and carbon nanotube (CNT) composite are described. The polythiophene (PTh) and polythiophene/ multiwalled carbon nanotube (PTh/MWCNT) composite are prepared chemically by oxidative polymerization of thiophene(Th). The formation of PTh and incorporation of CNTs into PTh are confirmed by Fourier Transform – Infrared spectroscopy (FT-IR) and Energy Dispersive X-Ray analysis (EDAX) analysis. Scanning Electron Microscopic (SEM) analysis revealed the formation of polymer/CNT composite. SEM image of PTh shows a leaf like structure and image of PTh/MWCNT shows the incorporation of MWCNT into the PTh flakes. Atomic force microscopic (AFM) analysis shows the morphology of PTH and PTh/MWCNT. The structural features of Nanotube-Polymer association are observed by AFM studies. The electrical behaviour of prepared samples has been studied by measuring I-V characteristics at varying temperature. The dielectric properties of these samples have been studied at low frequencies (150-700 kHz) for varying temperature. The dielectric constant for PTh/MWCNT is found to be higher than PTh for all temperature ranges. Finally,theac electrical conductivity (�ac) and dielectric relaxation time calculations have been carried out by using the data available from dielectric m easurements and by employing a simple relationship. Conductivity shows a linear dependence on temperature and is also higher for PTh/MWCNT.