Radiowave dielectric dispersions of colloidal particles in KCl and LiCl electrolyte solutions

Abstract

The permittivity ϵ′ and dielectric loss ϵ″ of a colloidal suspension in KCl and LiCl electrolyte solution in the frequency range 5 kHz to 10 MHz and in the temperature interval 0 to 50°C have been measured. The absence of the Maxwell—Wagner effect, due to the particular values of the ionic conductivity, permits us to define with great accuracy the parameters describing the dielectric dispersion of counterions on the basis of the Schwarz—Schurr model. The surface charge density σ o and the two surface conductivities λ and λ o as a function of temperature have been obtained. No anomaly in the thermal dependence of these parameters has been found whereas our previous measurements evidenced a marked anomaly in the temperature dependence of the dielectric loss ϵ″ at microwave frequency. This circumstance may be of interest in understanding the molecular configuration of interfacial water.