Standard Gibbs free energy of micellization

The micelle sketched in Fig. 5.10 contains an asphaltene core with asphaltene molecules 2 resin molecules are adsorbed onto the surface of the core. In addition to resins that are part of the solvation shell surrounding the core, asphalt-free oil species are also present in the shell. The formation of the solvation shell around the asphaltene core lowers the Gibbs free energy. The standard Gibbs free energy of micelli-zation, AG , represents the standaird Gibbs free energy difference between (1) asphaltene molecules in the core, resin molecules in the shell, and (2) those and ri2 molecules in an infinite-dilution petroleum mixture  

When infinite dilution is used as the standard state, the expression for is 

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A number of parameters are introduced in the standard Gibbs free energy of micellization (that is, Eq, (5.64b)) and the total Gibbs free energy expression (that is, Eq. (5.84)). These parameters can be estimated from the chemical structure of the species and other measurements. In the folio ing, numerical values for these peirameters will be discussed. 

Example 5.6 Show that the standard Gibbs free energy of micellization can... 

Solution Since amphiphiles have a polar head, they arc expected to coadsorb with resins onto the micellar-core surface. Therefore, one needs to modify both AG and the Gibbs free energy of the liquid phase L. In the following, we will briefly present the modifications to The standard Gibbs free energy of micellization, including the co-adsorption of the amphiphiles, can be expressed as,... 

AGt° is the standard Gibbs free energy of transfer of the ionic surfactant between water and the solvent s AG °mlc is the same quantity defined between a micelle in water and in solvent s. 

To quantify the effect of additives in the mixture on the micellization process, the standard Gibbs free energy change of micellization, dmicG , and the standard Gibbs energy of adsorption, dadsC , were calculated by using equations (5) and (6),... 

In order to further discuss the temperature effect by a scaling theory in polymer science, the quantity of log CMC was converted to the standard Gibbs free-energy change of micellization AG by eq. (1). 

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