Role Of Doped ZnO Nanoparticles As Polymer Chain Segmental Motion Exciter In PVA-ZnO Nanocomposites
Shobhna Choudhary, Ram J. Sengwa
Volume 2, Issue 5, Page 315-324 , Year 2017 | DOI: 10.5185/amp.2017/507
Keywords: Nanodielectric, dielectric properties, electrical conductivity, X-ray diffraction, polymer dynamics
Abstract: The dielectric and electrical spectra of solution cast prepared nanocomposite films comprising poly(vinyl alcohol) (PVA) as polymer matrix and zinc oxide (ZnO) as inorganic nanofiller (PVA–x wt% ZnO (x = 0, 1, 3 and 5)) have been investigated in the frequency range from 20 Hz to 1 MHz. Anomalous increase is observed in real part of complex permittivity with increase of ZnO concentration, whereas relaxation peak corresponding to PVA chain segmental motion is appeared in the intermediate frequency region of dielectric loss tangent and the loss part of electric modulus spectra of the nanocomposites. These results confirm that the interaction of ZnO nanoparticles with hydroxyl groups of PVA acts as exciter for polymer chain segmental dynamics in the nanocomposites. The temperature dependent dielectric investigations on PVA–3 wt% ZnO film reveal that the dielectric polarization and chain segmental dynamics increase with the increase of temperature. The dielectric relaxation and conductivity activation energies values of the film are determined from the Arrhenius relation, which are found equal. The X-ray diffraction study confirms that the crystalline phase of PVA matrix abruptly reduces with doping of only 1 wt% ZnO which suggests that the interaction of polymer-nanoparticles significantly alter the hydrogen bonded crystalline structure of pristine PVA matrix. The dielectric and electrical results showed that these nanodielectrics are potentially useful as an electrical insulation material for various electronic devices. Copyright © 2017 VBRI Press.