Table of Contents
ISRN Thermodynamics
Volume 2013, Article ID 280101, 7 pages
Research Article

Thermodynamic and Interfacial Properties of DTABr/CTABr Mixed Surfactant Systems in Ethanolamine/Water Mixtures: A Conductometry Study

1Chemistry Department, Adekunle Ajasin University, Akungba-Akoko 001, Nigeria
2Chemistry Department, Lagos State University, Ojo Apapa, Lagos 0001, Nigeria
3Department of Chemistry, Obafemi Awolowo University, Ile Ife 432, Nigeria

Received 21 October 2013; Accepted 13 November 2013

Academic Editors: M. Appell and C. Pierleoni

Copyright © 2013 Olaseni Segun Esan et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


Mixed-micelle formation in the binary mixtures of dodecyltrimethylammonium bromide (DTABr) and cetyltrimethylammonium bromide (CTABr) surfactants in water-ethanolamine mixed solvent systems has been studied by conductometric method in the temperature range of 298.1 to 313.1 K at 5 K intervals. It was observed that the presence of ethanolamine forced the formation of mixed micelle to lower total surfactant concentration than in water only. The synergistic interaction was quantitatively investigated using the theoretical models of Clint and Rubingh. The interaction parameter β12 was negative at all the mole fractions of DTABr in the surfactant mixtures indicating a strong synergistic interaction, with the presence of ethanolamine in the solvent system resulting in a more enhanced synergism in micelle formation than in water only. The free energy of micellization values was more negative in water-ethanolamine mixed solvent system than in pure water indicating more spontaneity in mixed micelle formation in the presence of ethanolamine than in pure water.