Solubilizate Molecules among Micelles

If the concentration of solubilizates incorporates into micelles is close to or higher than the micellar concentration, we have to think about the distribution of solubilizates among micelles. As with solubilization, the distribution of solubilizates among micelles can be handled successfully only by rearding micelles as chemical species. The equations in Section 9.3 clearly indicate that the association constants between micelles and solubilizates determine the distribution of solubilizates among micelles. The stepwise association constants Kj and the concentration of MR, are given 

the average number of solubilizate molecules per micelle, is given by 

the probability that a micelle is associated with i solubilizates can be written from Eq. (9.5) as 

This expression is exactly the same as the Poisson distribution. Equation (9.17) is derived by summing m to infinity. 

As m becomes high, the present solubilization model ceases to fit the physical state of the micelles, as is clear from the above assumption. However, when the R values are low, an important portion of the summation ranges up to only twice R  

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Several groups of investigators have looked at the effect of reverse micelles on reactions involving small molecules or ions a rationalization of the kinetic data obtained requires some knowledge about a) the solubilization sites for the small molecules within the micelles b) the nature of the water pool and c) the dynamics of solubilizate exchange among micelles. From a practical point of view, carrying out... 

The formal kinetics of reactions in micelles requires one to take into account the distribution of the reactant molecules between the micelles and the bulk solution, and also among the micelles. There are two approaches that take into account the distribution of the solubilizates between the micelles and the bulk phase. The first one is called the pseudophase model , the second one is referred to as the microscopic approach . 

Solubilizate binding constants have been determined for a few reverse micelle -small molecule (phenols, imidazole, simple alcohols) combinations [60, 63, 64]. In the case of imidazole binding to dodecylammonium propionate (DAP) reverse micelles, the use of the chemical shift dependence on DAP concentration for imidazole protons led to nonunique (i. e., proton-dependent) binding constants, a physically unreasonable situation [64]. When one is studying chemical reactions involving reactants which partition among the water pools, with the surfactant layer on the... 

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