The dielectric response of concentrated latices

Abstract

Dielectric response measurements can, in principle, provide important information on the concentration of colloidal particles, their shape and charge, and the composition of the background electrolyte. In this paper we present measurements of the effect of particle volume fraction on the dielectric response of concentrated latices in the frequency range 1-10 MHz, a range where the theory predicts large dielectric dispersion effects. It is found that the measurements on suspensions with a volume fraction of 0.3 or more are in accordance with a result obtained using a cell model. As the volume fraction decreases the departures from the formula increase, but these may be due to errors in our measurement of the particle contribution to the complex conductivity at these low volume fractions. © 1987.