Abstract
The stability of emulsions is examined from the points of view of thermodynamics as well as dynamics. First a statistical thermodynamical treatment is developed, which demonstrates that, in contrast to usual emulsions, microemulsions can be stable from a thermodynamic point of view. The expression established for the free energy of formation of microemulsions predicts phase inversion from one type of microemulsion to the other one as well as phase separation. Several basic types of multiphase systems are found theoretically:
-
(1)
microemulsion in equilibrium with another (in particular dilute) microemulsion of oil-in-water;
-
(2)
microemulsion in equilibrium with another (in particular dilute) microemulsion of water-in-oil, and
-
(3)
a dilute microemulsion of water-in-oil in equilibrium with a dilute microemulsion of oil-in-water. Similar multiphase systems have been previously identified experimentally by Winsor and by Healy et al. The present expressions also explain the low values of the interfacial free energy between two microemulsion phases in equilibrium. Second, a transport equation is established for a concentrated colloidal system. Based on this equation conditions are identified when the system is stable or unstable to small perturbations and information about its time evolution obtained. This dynamic approach provides a time scale for significant changes to occur in an unstable system.
Access this chapter
Tax calculation will be finalised at checkout
Purchases are for personal use only
Preview
Unable to display preview. Download preview PDF.
References
B. V. Derjaguin and L.D. Landau, Acta Physico-chimica 14, 633 (1941).
E. W. J. Verwey and J.Th.G. Overbeek, “Theory of the Stability of Lyophobic Colloids,” Elsevier, New York, Amsterdam, 1948.
W. Albers and J. Th. G. Overbeek, J. Colloid Sci. 14, 501 (1959).
W. Albers and J. Th. G. Overbeek, J. Colloid Sci. 14, 510 (1959).
T. P. Hoar and J. H. Schulman, Nature 152, 103 (1943).
J. H. Schulman and T. S. McRoberts, Trans. Faraday Soc. 42B, 165 (1946).
J. H. Schulman and D. P. Riley, J. Colloid Sci. 3, 383 (1948).
J. H. Schulman, W. Stocckenius, and L. M. Prince, J. Phys. Chem. 63, 1677 (1959).
W. Stocckenius, J. H. Schulman, and L. M. Prince, Kolloid Z. 169 170 (1960).
J. H. Schulman and J. A. Friend, J. Colloid Interface Sci. 4, 1988 (1971).
L. M. Prince, J. Colloid Interface Sci. 23, 165 (1967).
D. O. Shah, A. Tamjeedi, J. W. Falco, and R. D. Walker, Jr., AIChE J. 18, 1116 (1972).
G. Gillberg, H. Lehtinen, and S. Friberg, J. Colloid Interface Sci. 33, 215 (1970).
S. I. Ahmed, K. Shinoda, and S. Friberg, J. Colloid Interface Sci. 47, 32 (1974).
J. W. Falco, R. D. Walker, Jr., and D. O. Shah, AIChE J. 20, 510 (1974).
P.A. Winsor, “Solvent Properties of Amphiphilic Compounds,” Butterworth’s Scientific Publications, London, 1954.
R. N. Healy, R. L. Reed, and D. G. Stenmark, Soc. Pet. Eng. J. 147 (June 1976).
K. Shinoda and S. Friberg, Adv. Colloid Interface Sci. 4, 281 (1975).
E. Ruckenstein and J. C. Chi, J. Chem. Soc. Faraday Trans. II 71, 1690 (1975).
J. W. Cahn and J. E. Hilliard, J. Chem. Phys. 28, 258 (1958).
H. Metiu and E. Ruckenstein, J. Colloid Interface Sci. 46, 394 (1974).
A. Silberberg and W. Kuhn, Nature 170, 450 (1952).
W. Kuhn, H. Majer, and F. Burckhart, Heim. Chim. Acta. 43, 1208 (1960).
G. Langhammer and L. Nestler, Makromoleculare Chemie 88, 179 (1965).
A. Vrij, J. Polym. Sci. A-2, 6, 1919 (1968).
T. Nose, Polymer Journal (Japan) 8, 96 (1976).
S. Agarwal and H. Herman, Scripta Met. 7, 503 (1973).
J. W. Cahn, J. Chem. Phys. 42, 93 (1965).
E. Ruckenstein, Stability of Concentrated Colloidal Systems (unpublished 1972).
R. B. Bird, W. E. Stewart and E. N. Lightfoot, Transport Phenomena, John Wiley & Sons, New York (1960).
Author information
Authors and Affiliations
Editor information
Editors and Affiliations
Rights and permissions
Copyright information
© 1977 Plenum Press, New York
About this chapter
Cite this chapter
Ruckenstein, E. (1977). Stability, Phase Equilibria, and Interfacial Free Energy in Microemulsions. In: Mittal, K.L. (eds) Micellization, Solubilization, and Microemulsions. Springer, Boston, MA. https://doi.org/10.1007/978-1-4613-4157-4_15
Download citation
DOI: https://doi.org/10.1007/978-1-4613-4157-4_15
Publisher Name: Springer, Boston, MA
Print ISBN: 978-1-4613-4159-8
Online ISBN: 978-1-4613-4157-4
eBook Packages: Springer Book Archive