Ammonium ionic liquid as modulator of the critical micelle concentration of ammonium surfactant at aqueous solution: conductimetric and dynamic light scattering (DLS) studies

Hocine Sifaoui; Katarzyna Lugowska; Urszula Domańska; Ali Modaressi; Marek Rogalski

doi:10.1016/j.jcis.2007.05.079

Ammonium ionic liquid as modulator of the critical micelle concentration of ammonium surfactant at aqueous solution: conductimetric and dynamic light scattering (DLS) studies

J Colloid Interface Sci. 2007 Oct 15;314(2):643-50. doi: 10.1016/j.jcis.2007.05.079. Epub 2007 Jun 5.

Authors

Hocine Sifaoui¹, Katarzyna Lugowska, Urszula Domańska, Ali Modaressi, Marek Rogalski

Affiliation

¹ Laboratoire de Thermodynamique et de Modélisation Moléculaire, Faculté de Chimie, USTHB, BP 32 El-Alia, 16111 Bab-Ezzouar, Alger, Algérie.

PMID: 17618639
DOI: 10.1016/j.jcis.2007.05.079

Abstract

We report measurements of self aggregation in aqueous solution of an ionic liquid (IL), didecyl-dimethylammonium nitrate ([DDA][NO(3)]) and a surfactant hexadecyl-trimethylammonium bromide (CTAB) and of mixtures of these two salts. The electrical conductivity and dynamic light scattering (DLS) measurements were used for the characterization of the aggregation process. The conductivity measurements were performed at three temperatures. The critical micelle concentration (CMC) was determined at different temperatures and at different ratio of two salts. The effect of IL on the micellization of CTAB has been discussed. Our results suggest that organized structures formed by CTAB and [DDA][NO(3)] self assembly in domains of several hundred nanometers size. The micellar solubility of the salicylic acid in mixed salt aqueous solutions was determined to probe the physical properties of these assemblies. We have observed, that the micellar solubility enhancement was only slightly influenced by the nature of micelles present in aqueous solution. This proves that salicylic acid solubilization is enthalpy driven.