Mixed micelles diffusion coefficient

Interactions between oppositely charged micelles in aqueous solutions spontaneously form vesicles. The self-diffusion coefficient of water and 2H relaxation of 2H-labeled dodecyl trimethyl ammonium chloride of the dodecyl trimethyl ammonium chloride-sodium dodecyl benzenesulfonate systems show that in these mixtures there is limited growth of the micelles with changes in composition. The vesicles abruptly begin to form at a characteristic mixing ratio of the two surfactants. The transition is continuous.205 Transformation from micelle to vesicle in dodecyl trimethyl ammonium chloride-sodium perfluoro-nonanoate aqueous solution has been studied by self-diffusion coefficient measurements, and it was found that at a concentration of 35 wt% with a molar ratio of 1 1, the self-diffusion coefficient of the mixed micelles is far smaller than that of the two individual micelles.206 The characteristics of mixed surfactant... 

As discussed, the major determinant of the distribution coefficient between the aqueous phase and the oil phase of relatively nonpolar lipids such as cholesterol is the concentration of lipolytic products in the aqueous phase, since the paraffin chains of the lipolytic products, forming the lipid core of the micelle, are responsible for its solvent capacity (23,73). Micelle formation and the associated appearance of new solvent properties result from a cooperative effect of bile acids and lipolytic products (Fig. 16). Bile acids alone aggregate to form micelles, but these micelles have extremely poor solvent properties. Lipolytic products alone form very large liquid crystalline aggregates which probably have excellent solvent properties for lipids. When mixed, micelles of intermediate size are formed. The size is sufficiently small to permit rapid diffusion, and the lipolytic products in the center of the micelle provide a core of liquid hydrocarbon with useful solvent properties. 

With nonionic surfactants, it is possible to generate an oil-in-water droplet to bicontinuous structural transition at constant composition by increasing the temperature. This transition can be studied in more detail by using self-diffusion experiments with mixed solvents. In a system where the oil was an equal weight mixture of cyclohexane (1) and hexadecane (2) the transition from normal oil-swollen micelles to a bicontinuous microstructure was studied by monitoring the variation of the self-diffusion coefficient ratio, K = as a... 

The influence of micellar diffusion coefficient on the flux is shown in Fig. 4.29c diffusion coefficient of the micellar species can be decreased by addition of salt, formation of large mixed micelles, etc., as discussed in Chapter 3. The profiles obtained in this theoretical analysis can be compared with the experimental results shown in Fig. 4.28 and in Fig. 4.30 which shows the dialysis rate of... 

---