Dilute systems of dipoles and dipolar charged particles

Abstract

We analyse, by cluster expansion methods, the behaviour of a classical system made up of different kinds of particles which can have, besides an electrical charge, an electrical dipole moment.

It is shown that a Mayer resummation procedure can be applied also in this case, provided the g-bond is suitably chosen.

In our model the g-bond is such that (a) it approximates fairly well, outside a small region, the electrostatic potential, (b) it has a Fourier transform; (c) its form is such that, after integration over dipole orientations, the Fourier transforms of the chain graphs become independent on the ordering of the species at the intermediate vertices.

The expression for the resulting q-bond and that for the excess free energy, in the ring approximation, is explicitly worked out.

The relevance of this model to electrolytes is briefly discussed, also from a numerical point of view.