AC conductivity and dielectric spectroscopic studies of polypyrrole-titanium dioxide hybrid nanocomposites

✍ Scribed by Kumar, A. ;Sarmah, S.

• Book ID: 105366332
• Publisher: John Wiley and Sons
• Year: 2011
• Tongue: English
• Weight: 781 KB
• Volume: 208
• Category: Article
• ISSN: 0031-8965
• DOI: 10.1002/pssa.201026721

✦ Synopsis

Abstract

Dielectric spectroscopy and AC conductivity measurements have been employed to investigate the electrical properties of disordered materials in a wide range of temperature. In this work, conducting polypyrrole–titanium dioxide (PPy–TiO~2~) hybrid nanocomposites have been synthesized by oxidizing pyrrole in presence of different concentration (wt%) of TiO~2~ nanoparticles. Thermal stability of the nanocomposites increases with the increase in TiO~2~ wt%. The dielectric and electric modulus studies of as prepared samples were carried out over a frequency range of 42 Hz–5 MHz. The dielectric constant and dielectric loss for all the nanocomposite samples were observed to decrease with the increase of frequency. Electric modulus analysis has been carried out to understand the electrical relaxation processes. The dielectric relaxation time of nanocomposites decreases with the increase of TiO~2~ nanoparticles concentration. AC conductivity measurements show that correlated barrier hopping conduction mechanism can be employed for pure PPy and PPy‐5 wt% TiO~2~ nanocomposites, whereas large polaron tunnelling mechanism is applicable for higher concentration of TiO~2~ (10–25 wt%) in PPy–TiO~2~ nanocomposites.