Dielectric Absorption in Dispersed Systems

Abstract

IF a high-frequency alternating field is applied to a system containing mobile ions or movable dipoles, the loss factor should increase when the applied frequency approaches the natural relaxation frequency of the system. In dilute aqueous solutions of simple electrolytes this frequency is of the order 100 Mc./s. (Falkenhagen effect); in pure water it is 10,000 Mc./s. (dipole oscillation effect). With polyelectrolytes the cylindrical symmetry of the ionic atmosphere results in a much slower relaxation (0.1–1 µ sec.)1, and we have now found a similar effect but with a much higher loss factor for microscopic two-phase systems, such as fibres, suspensions and emulsions, with water as the continuous phase. It also occurs in disperse systems where the continuous phase is an insulator, and is indeed more easily verified than with aqueous systems, when the frequency-independent conductance may mask the critical frequency effect.