Characterization of SiO₂ nanoparticles dispersed (PVA–PEO) blend based nanocomposites as the polymeric nanodielectric materials

Abstract

Polymer nanocomposite (PNC) films consisting of poly(vinyl alcohol) (PVA) and poly(ethylene oxide) (PEO) blend matrix dispersed with nanosize particles of silicon dioxide (SiO₂) [i.e., (PVA-PEO)–<i>x</i> wt% SiO₂, where <i>x </i> is 0, 1, 3 or 5] have been prepared by aqueous solution-cast method. The structural properties of the PNCs are characterized by X-ray diffraction measurements, which confirm the semi-crystalline structures of these materials. The complex dielectric function, alternating current electrical conductivity, electric modulus and impedance spectra of the PNC films have been investigated in the frequency range 20 Hz to 1 MHz by employing the dielectric relaxation spectroscopy. Effects of SiO₂ concentrations and temperatures on the dielectric permittivity, electrical conductivity and structural dynamics of these PNC materials have been explored. The dielectric relaxation mechanism of the PVA–PEO blend based these materials is mainly governed by the PEO chain segmental dynamics. The relaxation times and conductivity activation energies of the PNC films are determined from the Arrhenius plots. Dielectric and electrical parameters values reveal the suitability of these materials as low-permittivity nanodielectrics for the radio frequency electric field.