On the Assessment of Dielectric Relaxation Parameters of Liquids

Abstract

In an attempt to outline roughly the "normal” dielectric relaxation behaviour of polar liquids as a reference for the investigation of more complex (e.g. associating) systems, some theoretical considerations and experimental results (mainly on two component mixtures) are presented. They show that for a distinct spectral component a simple equation can be used which approximately relates the relaxation strength to the moment of the relaxing moiety. The rotational relaxation time is practically not affected by the static permittivity but is correlated to the molecular size and the macroscopic viscosity, thus allowing for conclusions on the effective radius of the tumbling moieties.