Pseudophase Model of the Micelle

Micelles and bulk aqueous solvents are regarded as distinct reaction regions. 

Micellar effects on reaction rates and equilibria are insensitive to changes in the size and shape of micelle. 

Equilibrium processes or equilibrium constants for micellar incorpo-ration/solubilization of different solubilizates are independent of each other, i.e., there is no cross-interaction between equilibrium constants of micellar incorporation of different solubilizates. 

For a bimolecular reaction, the reaction between a reactant (R ) in the micellar pseudophase and the other reactant (S ) in the aqueous pseudophase does not occur i.e., the cross-interface reaction such as that between and or R and does not take place. 

In view of assumption 1, each micelle acts as a microreactor of one domain that provides a new reaction medium and alters the distributions of reactants in solution. Thus, the classical PP model may also be called the two-domain pseudophase model of micelles, in which the bulk aqueous region and the entire micellar pseudophase are considered to be two different reaction domains. A refinement of Equation 3.2 consists of including the possibility of different reaction domains within the micelle. A three-domain pseudophase model is one in which, for example, the bulk aqueous region, the Stem region, and the hydro-phobic micellar core are treated as separate reaction regions.  

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Even though micelles should be treated as a chemical species, a pseudophase model of the micelle is also of considerable practical importance for estimating CMC values of mixed surfactants. Therefore, the following discussion may be regarded as a practical effort to derive an empirical equation for mixed micelles. First, however, it is instructive to know how... 

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