Solute-micelle interactions, quantitative

ASSESSMENT OF SOLUTE-MICELLE INTERACTIONS IN ELECTROKINETIC CHROMATOGRAPHY USING QUANTITATIVE STRUCTURE-RETENTION RELATIONSHIPS... 

QSRR studies in MEKC involving LSS with LSD are scarce and not helpful in delineating solute-micelle interactions but are useful for predictive purposes (22). Typically, LSD are screened in quantitative structure activity relationships (QSAR) studies where the exact nature of the relationship between the solute structure and biological activity is hardly established by a physicochemical model. Just for reference, data mining procedures for LSD and statistical modehng aspects of QSRR using chromatographic data have been reviewed recently (23). 

A useful experimental method, providing quantitative information for the micelle-micelle interactions (in not too concentrated solutions), is the static light scattering (SLS). This method is based on the measurement of the concentration dependence of the scattered light and the solution refractive index [402,403]. From the intensity of the scattered light, the Rayleigh ratio, i e is determined and the data are plotted in accordance with the Debye equation [402-404]... 

Interactions between cationic micelles and uni- and divalent anions have been treated quantitatively by solving the Poisson-Boltzmann equation in spherical symmetry and considering both Coulombic and specific attractive forces. Predicted rate-surfactant profiles are similar to those based on the ion-exchange and mass-action models (Section 3), but fit the data better for reactions in solutions containing divalent anions (Bunton, C. A. and Moffatt, J. R. (1985) J. Phys. Chem. 1985, 89, 4166 1986,90, 538). 

For separating and purifying proteins, a forward extraction operation facilitates the selective transfer of a target protein from an aqueous solution containing some kinds of proteins into an organic phase, and the extracted proteins are quantitatively recovered into a fresh aqueous solution by the subsequent back extraction. The transfer selectivity is based on the interaction between surfactants, which form reverse micelles, and the protein surface. On the other hand, the quantitative recovery of an objective protein from reverse micelles is accomplished by severing proteins from the enclosure with a surfactant layer. 

For a reactant molecule or ion in a micellar solution or microemulsion, predictions of electron transfer kinetics at electrodes need to consider [14] (1) the distance between the electrode and the reactant, (2) the environment surrounding the reactant at the time of electron transfer, (3) structure and dynamics of surfactant aggregates on the electrode, and (4) dynamics of interactions of the reactant with surfactant structures on the electrode and with micelles. A molecular picture of these events during electron transfer is by no means clear, and quantitative predictions are not possible at this time. A qualitative view of the above factors is given in the following paragraphs. 

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