Dielectric dispersion and ionic conduction in hydrocolloids of poly (vinyl alcohol)–poly(ethylene oxide) blend–montmorillonite clay nanocomposites

Abstract

395-402The relative complex dielectric function, electric modulus, alternating current (ac) electrical conductivity and complex impedance spectra of poly(vinyl alcohol) (PVA)–poly(ethylene oxide) (PEO) blend loaded with montmorillonite (MMT) clay nano-platelets up to 10 wt.% in aqueous colloidal suspensions are investigated over the frequency range 20 Hz - 1 MHz at 27oC. The relaxation time corresponding to electrode polarization and ionic conduction processes are determined from the complex spectra of intensive dielectric quantities. The direct current (dc) electrical conductivity of these materials is evaluated by the fitting of real part ac conductivity data to the Jonscher power law, which increases significantly at higher clay concentration. The behaviour of ionic conduction with increase of clay concentration is discussed considering intercalation of the polymers blend in clay galleries with the formation of lamellar nanostructures, and the effect of exfoliated MMT clay nanoplatelets on these structures. Contribution of PVA and PEO on the ionic conduction and electrode polarization phenomena is explored in the hydrocolloids of PVA–PEO blend –MMT clay from the comparative study of various dielectric parameters with the PVA–MMT clay and PEO–MMT clay hydrocolloids