Potentiometric Study of Intermolecular Interactions in Cationic-Nonionic Mixed Surfactant Systems

Abstract

The nature and thermodynamics of interactions of the cationic surfactant dodecyltri methylammonium bromide (DTA) with the nonionic surfactant Triton X-100 (TX100) in mixtures are studied using the potentiometric method. We investigate the influence of temperature, the addition of KBr, and the concentrations of DTA and TX100 on the complex formation between free DTA cations and TX100 nonionic micelles in solution. Binding isotherms, distribution coefficients K_x, and stoichiometric equilibrium constants K ₁ are determined from the experimental data. The standard free energy change (ΔG ₁°), the standard enthalpy change (ΔH ₁°) and the standard entropy change (ΔS ₁°) are calculated for transferring the free DTA cation from the aqueous bulk phase to the TX100 nonionic micelle phase. Our results support the assumption that hydrophobic interactions are the most important in this binding process.

Get full access to this article

View all access options for this article.

References

Benrraou, M. , Zana, R. , Varoqui , R. , and Pefferkom, E. , Study of the Interaction between Dodecyltrimethylammonium Bromide and Poly(maleic acid-co-alkyl vinyl ether) in Aqueous Solution by Potentiometry and Fluorescence Probing , J. Phys. Chem. 96, 1468-1475 (1992 ).

Cutler, S.G. , Meares, P.J. , and Hall, D.G. , Surfactant-Sensitive Polymeric Membrane Electrodes, Electroalnal. Chem. 85, 145-148 (1977).

Datyner, A. , "Surfactants in Textile Processing," Surfactant Science Series, vol. 14, Marcel Dekker, Inc., NY, 1983.

De Lisi, R. , Inglese, A. , Milioto, S. , and Pellerito, A. , Demixing of Mixed Micelles, Thermodynamics of Sodium Perfluorooctanoate-Sodium Dodecanoate Mixtures in Water, Langmuir 13, 192-202 (1997).

Fletcher, J.E. , A Generalized Approach to Equilibrium Models , J. Phys. Chem. 81/25, 2374-2378 (1977).

Jha, R. , and Ahluwalia, J.C. , Thermodynamics of Micellization of Triton X-100 in Aqueous Ethylene Glycol Solutions, J. Phys. Chem. 95, 7782-7784 (1991).

Johnson, A. , "The Theory of Coloration of Textiles," Society of Dyers and Colourists, Bradford, U.K., 1989.

Klotz, I.M. , "Introduction to Biomolecular Energetics, Including Ligand-Receptor Interactions," Academic Press, NY, 1986.

Laguitton-Pasquier, H. , Pansu, R. , Chauvert , J.P. , Collet, A. , and Faure, J. , A Study of the Microscopic Structure of Mixed Cationic/Nonionic Micelles by NMR and Time-Resolved Fluorescence Spectroscopy, Synthet. Metals 81, 309-314 (1996).

10.

Moore, W.J. , "Physical Chemistry," Longman Scientific and Technical , London, 1972.

11.

Morf, W.E. , "The Principles of Ion-Selective Electrodes and of Membrane Transport ," Akademiai Kiado, Budapest, Hungary, 1981.

12.

Ogino, K. , and Abe, M. , "Mixed Surfactant Systems," Surfactant Science Series , vol. 46, Marcel Dekker, Inc. , NY, 1993.

13.

Rosen, M.J. , "Surfactants and Interfacial Phenomena," John Wiley and Sons, Inc., NY, 1989.

14.

Satake, I. , and Yang, J.T. , Interaction of Sodium Decyl Sulfate with Poly(L-ornithine) and Poly(L-lysine) in Aqueous Solution, Biopolymers 15, 2263-2275 (1976).

15.

Schick, M.J. , "Nonionic Surfactants, Physical Chemistry ," Surfactant Science Series, vol. 23, Marcel Dekker, Inc., NY, 1987.

16.

Shirahama, K. , Nishiyama, Y. , and Takisawa, N. , Binding of N-Alkylpyridinium Chlorides to Nonionic Micelles. J. Phys. Chem. 91, 5928 -5930 (1987).

17.

Shore, J. , "Colorants and Auxiliaries, Organic Chemistry and Application Properties, Vol. 2. Auxiliaries," Society of Dyers and Colourists, Manchester, U.K., 1990.

18.

Simončič. B. , and Špan , J. , A Study of Dye-Surfactant Interactions, Effect of Chemical Structure of Acid Dyes and Surfactants on the Complex Formation, Dyes Pigments 1, 1-14 (1998).

19.

Simončič, B. , Špan, J., and Vesnaver, G. , Acid Red 88 Dye Anion-Selective Electrode, Dyes Pigments 25, 69-78 (1994).

20.

Škerjanc, J. , Kogej, K. , and Vesnaver, G. , Polyelectrolyte-Surfactant Interactions, Enthalpy of Binding of Dodecyl-and Cetylpyridinium Cations to Poly(styrenesulfonate) Anion, J. Phys. Chem. 92, 6382-6385 (1988 ).

21.

Thomas, H.G. , Lomakin, A. , Blankschtein , D. , and Benedek, G. , Growth of Mixed Nonionic Micelles, Langmuir 13, 209-218 (1997).