Electrical conductivity and permittivity measurements near the percolation transition in a microemulsion. II. Interpretation

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Abstract
In this paper I compare the conductivity and permittivity measurements reported in the previous paper near the percolation transition in a microemulsion to (i) the predictions of the Bruggeman theory and suitable extensions of this theory, and (ii) models for percolation in dynamic systems. Consideration of the frequency dependence and also an earlier comparison between conductivity and molecular diffusion data show that the stirred percolation model of M. Laguës [J. Phys. Lett. 40, L331 (1979)] cannot explain the raised conductivity exponent observed below the percolation transition in the microemulsion studied here. The Bruggeman theory predicts most of the features of the conductivity and permittivity near the percolation transition, in particular, the frequency dependence, observed in this microemulsion. G. S. Grest, I. Webman, S. A. Safran, and A. L. R. Bug [Phys. Rev. A 33, 2842 (1986)] have attributed the frequency dependence of the conductivity observed in microemulsions with a spherical-droplet structure to dynamic effects. Dynamic effects have little effect on the frequency dependence of the conductivity in the microemulsion studied here. Although this microemulsion is structurally different from that studied by Grest et al., the analysis presented here provides a critical test of their dynamic percolation model.