DIELECTRIC-RELAXATION OF NONCONDUCTING COLLOIDAL PARTICLES IN NONBINARY SOLUTIONS - MUTUAL ENHANCEMENT OF ADSORPTION OSCILLATIONS

This paper deals with the low-frequency dielectric dispersion (LFDD) o f colloidal suspensions with non-binary electrolyte solutions as dispe rsion media. Starting from the theory of double-layer concentration po larization in AC fields, it is demonstrated that counterions can under go significant adsorption oscillations which can increase to a large e xtent the dielectric increment of the suspensions. It is also shown th at such oscillations can also affect the characteristic relaxation fre quency of the dielectric spectrum, omega(cr). This quantity call be ei ther larger or smaller than it would be in a purely binary electrolyte , in which adsorption oscillations do not occur. The predictions of th e theory are compared to experimental LFDD data reported in the litera ture. (C) 1997 Elsevier Science B.V.