Studies of structural, thermal and electrical behavior of polymer nanocomposite electrolytes

Structural, thermal and electrical behavior of polymer-clay nanocomposite electrolytes consisting of polymer (polyethylene oxide (PEO)) and NaI as salt with different concentrations of organically modified Na+ montmorillonite (DMMT) filler have been investigated. The formation of nanocomposites and changes in the structural properties of the materials were investigated by X-ray diffraction (XRD) analysis. Complex impedance analysis shows the existence of bulk and material-electrode interface properties of the composites. The relative dielectric constant (er) decreases with increase in frequency in the low frequency region whereas frequency independent behavior is observed in the high frequency region. The electrical modulus representation shows a loss feature in the imaginary component. The relaxation associated with this feature shows a stretched exponential decay. Studies of frequency dependence of dielectric and modulus formalism suggest that the ionic and polymer segmental motion are strongly coupled manifeasting as peak in the modulus (M '') spectra with no corresponding feature in dielectric spectra. The frequency dependence of ac (alternating current) conductivity obeys Jonscher power law feature in the high frequency region, where as the low frequency dispersion indicating the presence of electrode polarization effect in the materials.