Dielectric spectroscopy of hydrophilic polymers–montmorillonite clay nanocomposite aqueous colloidal suspension

Frequency-dependent complex dielectric function, loss tangent, electric modulus, alternating current electrical conductivity, and impedance spectra of poly(vinyl alcohol) (PVA), poly(vinyl pyrrolidone) (PVP), poly(ethylene glycol) (PEG), and blends of PVA–PVP and PVA–PEG, loaded with polymer grade montmorillonite (MMT) clay upto 5 wt% of solute (polymer + clay) in aqueous colloidal suspensions, have been investigated in the frequency range 20 Hz to 1 MHz at 27 °C. These materials show the dielectric dispersion corresponding to ionic conduction and electrode polarization phenomena in the experimental frequency range. The loss tangent peak frequency which separates the contribution of the bulk material and the electrode polarization phenomenon was used to evaluate the electrode polarization relaxation time corresponding to the dynamics of electric double layers. The dielectric and electrical conductivity spectra were interpreted as a result of these material complex structures formed by constituents H-bonding interactions, and the clay intercalation and exfoliation that alter the conduction pathways. Results show that the dielectric/electrical properties of the polymer–clay nanocomposites aqueous colloidal suspension have good resemblance to their structural properties, which were explored from other spectroscopic and morphological techniques. A close look on the dielectric parameters of the investigated materials proves the suitability for the synthesis of new materials with desirable and predicted properties.