Electric modulus based relaxation dynamics, ac-conductivity and I-V characteristics in PTh/[Co(EDTA)NH3Cl] H2O nanocomposite prepared by chemical oxidation method

A thread like nanocomposite material based on PTh/[Co(EDTA)NH3Cl] H2O has been successfully prepared by in-situ chemical oxidative polymerization for the investigation of dielectric properties. XRD reflects its crystalline nature with a particle size of 40 nm. TEM clearly showed a two phase system consisting of [Co(EDTA)NH3Cl] H2O (photoadduct) particles immersed in PTh threads. Thermogravimetry exhibits an increase in its thermal stability than pristine PTh. Enhanced dielectric constant of around (epsilon'aEuroe= 500 at 10(4) Hz) has been observed than many other systems reported recently. This is of conducive value for energy storage and has been attributed to (1) Maxwell-Wagner interfacial polarization and (2) increased aspect ratio due to the thread like structure. Moreover, the losses observed in the material are dominated by dc-conduction as has been confirmed by the electric modulus formalism. Frequency dependent conductivity (sigma(ac)) has been found to be of higher value (similar to 10(8) S/m), which saturates at high frequencies. Electric modulus formalism shows a change over from dc- to ac-conduction. I-V characteristics showed a typical ohmic behavior of nanocomposite with a resistance of 2.7 x 10(4) Omega, thereby excluding RS/PF or SCLC conduction mechanisms. Such a material can provide absorption and reflection to EMI shielding.