Investigation of AC Conductivity Scaling and Dielectric Relaxation Dynamics of Chitosan/Iron Complexes

Abstract

Complexes of chitosan-iron (Cs/Fe) were prepared electrochemically in acidic aqueous media in one compartment cells. The AC electrical conductivity of the Cs/Fe complexes was investigated in a wide range of frequency at various temperatures. The general behavior of the AC conductivity was found to be characterized by three different regions and, therefore, it was analyzed based on the universal power law to interpret the dispersive behavior of the conductivity. The activation energy (Ea ) of the conductivity was estimated and was found to be frequency dependent. The AC conductivity scaling of the complexes was investigated using various parameters. It was found that the conductivity spectra of all samples could be successfully collapsed into a master curve confirming that the relaxation mechanism was temperature independent under conductivity formalism in a certain range of temperature. The dielectric relaxation dynamics of the Cs/Fe complexes were investigated using the electric modulus. The behavior of the imaginary part of the electric modulus, M//(ω), of all samples showed asymmetric relaxation peaks with a red shift toward higher frequencies upon increasing the temperature. The Cole-Cole and scaling behavior of the real and imaginary parts of the electric modulus were investigated.