Modeling of the electrostatic interaction of ions in dry, isolated micelles of AOT by the method of direct optimization

A simple model of a dry reversed micelle of ionic surfactants is proposed, according to which during the optimization procedures the ions move over certain closed surfaces in a vacuum at T = 0 K The electrostatic interactions of discrete ions in dry, reversed micelles of AOT are calculated as a function of the sizes of the ions, ion charges, and the optimum positions of the ions in the polar cavity of the micelles. It is shown that when the counterions penetrate the layer of the potential-determining ions. the electrostatic interaction begins to favor the self-organization of the ionic surfactants over that of the reversed micelles. The distribution of the electrostatic potential in the polar cavity of micelles of different shapes (a sphere, a spheroid, a prolate ellipsoid) is calculated. In the models in which the charge is taken to be discrete, the electrostatic field extends beyond the double electric layer (DEL); the sign of the potential coincides with that of the counterion. It is shown that in the analysis of structures of dry, reversed micelles the possibility of the formation of voids (in the surface layer of polar groups and in the center) as well as the density of packing should be taken into account by using a specially developed approach. The most probable structural parameters of AOT micelles are determined for different counterions (Li+, Na+, Cs+, [Co(H2O)(6)](2+), La3+).