“¿Are the mixtures of homologous surfactants ideal?”

PABLO C. SCHULZ, JOSE L. RODRÍGUEZ, ROSSANA MINARDI, MARÍA BELÉN SIERRA, MARCELA A. MORINI

JOURNAL OF COLLOID AND INTERFACE SCIENCE

Elsevier

Año: 2006 vol. 303 p. 264 - 271

0021-9797

personal AbstractAbstract The interaction between homologous surfactants in mixed micelles was studied by the Regular Solution Theory of mixed micelles. The interaction is independent of the nature of the polar head groups and attractive and the interaction parameter βM depends linearly on the difference in chain length nC. The interaction becomes ideal at nC = 0.75 ± 0.06. Above nC ¡Ö 5, the dependence remains linear but the slope increased 2.7 times. The phenomenon is explained as the effect of the reduction of the hydrocarbon/water micelle interface and a better packing of the chains in the micelle core, caused by the inclusion of a shorter homologous surfactants. This reduction can be more effective when nC 5.βM depends linearly on the difference in chain length nC. The interaction becomes ideal at nC = 0.75 ± 0.06. Above nC ¡Ö 5, the dependence remains linear but the slope increased 2.7 times. The phenomenon is explained as the effect of the reduction of the hydrocarbon/water micelle interface and a better packing of the chains in the micelle core, caused by the inclusion of a shorter homologous surfactants. This reduction can be more effective when nC 5.nC. The interaction becomes ideal at nC = 0.75 ± 0.06. Above nC ¡Ö 5, the dependence remains linear but the slope increased 2.7 times. The phenomenon is explained as the effect of the reduction of the hydrocarbon/water micelle interface and a better packing of the chains in the micelle core, caused by the inclusion of a shorter homologous surfactants. This reduction can be more effective when nC 5.nC 5. © 2006 Elsevier Inc. All rights reserved.2006 Elsevier Inc. All rights reserved. Keywords: Mixed micelles; Homologous surfactants; Critical micelle concentration; Cationic surfactants; Alkyltrimethylammonium bromidesMixed micelles; Homologous surfactants; Critical micelle concentration; Cationic surfactants; Alkyltrimethylammonium bromides