The surfactant-polyelectrolyte analogy

Certain ionic surfactants self-assemble in aqueous solutions into giant flexible wormlike micelles that behave as equilibrium polyelectrolytes. In the mid-1980s the micelle-polymer analogy was first recognized in the solution properties of cationic micelles at high salt concentrations. Since then an extensive literature has developed dealing with rheological investigations, the use of electron microscopy, and the use of small-angle scattering techniques, among others, to further develop the analogy. Nevertheless, there are significant gaps in our knowledge concerning micellar growth laws, micellar flexibility, and intermicellar interactions in these fascinating systems. Several open questions are presented, and the utility of equilibrium polyelectrolytes as model systems for ordinary polyelectrolytes are noted.