Dielectric Study of Fractal Clusters Formed by Aqueous Nanodroplets in Apolar Media

Abstract
Dielectric investigations of fractal cluster formation near the percolation threshold were carried out on water‐in‐oil microemulsions consisting of water, Aerosol OT, and isooctane. Temperature‐dependent dielectric relaxation measurements in the frequency range 100 kHz to 1 GHz reveal the formation of fractal clusters as the percolation threshold is approached. The degree of ramification of the fractal clusters is phenomenologically characterized by a swelling factor. A repeated application of Bruggeman's unsymmetrical effective‐medium theory yields an internally consistent first‐order approximation which describes satisfactorily the characteristic features of the experimental results.