The conductivity of a foam

Abstract

We present a new analysis of the dependence of electrical conductivity on liquid fraction for a foam. Ignoring the contribution of the films to both the liquid content and the conductivity, we consider only the network of liquid-filled Plateau borders and the junctions at which they meet. The effect of the junctions is calculated in the form of a vertex correction to both the conductivity and liquid fraction of the network. The correction is sufficient to account for the deviation from the linear formula of Lemlich for liquid fractions up to about 10%.