Percolative phenomena and electrorheological structures in reverse micelles

Structural relaxations in AOT (sodium bis(2-ethylhexyl) sulphosuccinate) and lecithin reverse micelles are investigated by means of dielectric relaxation and conductivity measurements. The different behaviours exhibited by the two systems are interpreted in terms of the different kinds of interaction between the water and the surfactant molecules. In the case of lecithin, the application of an external electric field induces the establishing of some electrorheological structure. The temperature dependence of the observed electrorheological effects agrees with the hypothesis of a structural arrangement consisting in a percolated network of branched cylindrical micelles. The experimental results are compared with other literature data and discussed within the framework of the current theories.