Dielectric studies of non-electrolyte solutions. Part 1.—Electric permittivity and non-linear behaviour of mixtures of polar anisotropic molecules.

Abstract

A modification of Onsager's model taking into account molecular anisotropy is proposed for mixtures of polar liquids. Two formulae giving the concentration dependence of the electric permittivity and its variations under the influence of strong electric fields (dielectric saturation) are derived.

Comparison with experimental results for several mixtures shows that the variation of the dipole moments determined with these formulae over the whole range of concentration of a polar compound dissolved in a non-polar as well as in a polar solvent is less than 5 %. An application to the study of molecular association is proposed.