On the Structure of Five-Component Microemulsions
A family of 5-component microemulsions made with sodium 4-(1’-heptylonyl)-benzenesulfonate, iso-butyl alcohol, dodecane, and NaCl brines of various concentrations has been studied with small-angle neutron scattering (SANS) and quasielastic light scattering (QLS) methods. Both techniques show that when the water volume fraction, ФW, is either less than 0.20 or greater than 0.75, the size of the well-defined droplets (water in oil or oil in water) increases nearly linearly as the volume fraction of the dispersed phases increases. The water in oil droplets are spherical and polydispersed in size, while the oil in water droplets are prolate with an aspect ratio of approximately 3:1. For the intermediate aqueous volume fractions between 0.20 and 0.75, both the QLS and SANS results indicate that the length scales in the microemulsion phase vary approximately in proportion to Ф(1 − ФW). These observations favor a model of bicontinuous structure in the intermediate regime.
KeywordsSurfactant Quartz Acetone Titration Hydrocarbon
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- 1.P.A. Winsor, “Solvent Properties of Amphiphilic Compounds, ” Butterworths, London, 1954.Google Scholar
- 4.L. Auvray, J.-P. Cotton, R. Ober, and C. Taupin, J. Physique 45, 913 (1984).Google Scholar
- 7.L.E. Scriven, Nature 263, 123 (1976), and in “Micellization, Solubilization, and Microemulsions,” p. 877, K. Mittal, ed., Plenum, New York, 1977.Google Scholar
- 8.B. Chu in “Laser Light Scattering,” Academic Press, San Diego, California, 1974.Google Scholar
- 9.G.K. Batchelor, J. Fluid Mech. 74, (1976).Google Scholar
- 12.S. Hanna, W. Hess, and R. Klein, Physica 111A, 181 (1982).Google Scholar
- 17.E.J. Verwey and J.Th.F. Overbeek, in “Theory of the Stability of Lyophobic Colloids,” Elsevier, Amsterdam, 1948.Google Scholar
- 21.E. Jackman, in “Photon Correlation and Light Beating Spectroscopy,” H.Z. Cummins and E.R. Pike, eds., Plenum, New York, 1974.Google Scholar
- 29.S.A. Safran, this volume.Google Scholar
- 31.R.V. Sharma and K.C. Sharma, Physica 89A, 213 (1977).Google Scholar
- 36.K.E. Bennett, J.C. Hatfield, H.T. Davis, C.W. Macosko, and L.E. Scriven, in “Microemulsions, ” I.D. Robb, ed., Plenum, New York, 1982.Google Scholar