DEPLETION INTERACTIONS IN IONIC MICELLAR SOLUTIONS

The depletion interactions between macroions caused by the addition of a highly asymmetric electrolyte (micelles) were studied using the int egral equation technique. The three-component system contained the fol lowing species: macroions (component 1), charged micelles (2), and an equivalent number of small counterions (3). The ions are present as so ft charged spheres, and thus the three species differ widely in charge and size. We showed that the model, reproduces the major features of reported experimental results (Sober, D. L.; Walt, J. Y. Langmuir 1995 , 11, 2352), i.e., (i) the purely repulsive interaction between two ma croions in simple electrolyte solutions, (ii) the onset of the attract ive minimum above the critical micelle concentration, and (iii) the ap pearance of structural oscillations at high concentrations of added mi celles.