| Thermodynamic properties and aggregation behaviour of mixed micellar systems, comprised of sodium alkylcarboxylate salts, {dollar}rm Csb{lcub}n{rcub}Na{dollar} (where n = 8,10,12), ethoxylated alcohols, {dollar}rm Csb4EOsb{lcub}x{rcub}{dollar} (where EO = ethylene oxide group, X = 0,1,2,3,4), and n-alkyltrimethylammonium bromide salts, {dollar}rm RNMesb3Br{dollar} (where R = octyl, decyl, and dodecy), have been studied to characterize the micellization process of the surfactants and to explore the specificity of interactions that lead to distinctive solubilization behaviour of polyethylene alkyl ether compounds in anionic and cationic micelles. The changes in the apparent molar properties of the surfactant in the monomer state, {dollar}Ysbsp{lcub}phi,S{rcub}{lcub}S{rcub},{dollar} and in the micellar state, {dollar}Ysbsp{lcub}phi,S{rcub}{lcub}M{rcub};{dollar} the distribution coefficient of the alcohol, {dollar}rm Ksb{lcub}D{rcub}{dollar} between the micellar and aqueous phases; the change in the partial molar properties of the alcohol, {dollar}Delta Ysbsp{lcub}A{rcub}{lcub}M{rcub},{dollar} between water and the micellar phase; the aggregation numbers of the surfactant, {dollar}rm Nsb{lcub}S{rcub},{dollar} and alcohol, {dollar}rm Nsb{lcub}A{rcub},{dollar} in the mixed micelle, have been correlated with the chemical structure of the surfactants and alcohols.; The apparent molar volumetric properties of the binary aqueous surfactant systems were analyzed using a mass-action model, which provides a quantitative description of the surfactant micellization process.; The volumetric transfer functions for {dollar}rm Csb4EOsb{lcub}X{rcub}, Delta Ysb{lcub}A{rcub}(Wto W + S),{dollar} at a low concentration of 0.05 m (0.02 m in long chain surfactant systems), from water to the micellar phase were analyzed using a chemical equilibrium model to obtain the solubilization parameters of the alcohol in the micellar system, namely, the distribution coefficient, {dollar}rm Ksb{lcub}D{rcub},{dollar} and the change in the partial molar properties of the alcohol, {dollar}rm Delta Ysbsp{lcub}A{rcub}{lcub}M{rcub},{dollar} between water and the micellar phases.; The mean aggregation number, {dollar}rm Nsb{lcub}S{rcub},{dollar} of {dollar}rm Csb8Na{dollar} and {dollar}rm Csb{lcub}10{rcub}Na{dollar} in the mixed micelle, obtained from fluorescence quenching measurements, remains unchanged while the number of alcohol molecules solubilized in the micelle, {dollar}rm Nsb{lcub}A{rcub}{dollar} increases steadily as a function of the number of EO groups in the alcohol.; The different solubilization behavior of {dollar}rm Csb4EOsb{lcub}X{rcub}{dollar} alcohols in anionic and cationic micelles originates from the specificity of the interactions involving surfactant, alcohol, and water molecules in the formation of the micelles. (Abstract shortened by UMI.)... |
