Oil-continuous microemulsions composed of hexane, water, and 2-propanol

doi:10.1016/0021-9797(77)90313-7

Journal of Colloid and Interface Science

Volume 60, Issue 3, July 1977, Pages 488-496

https://doi.org/10.1016/0021-9797(77)90313-7 Get rights and content

Abstract

On the basis of conductivity and centrifugation data and visual examination, ternary phase diagrams were prepared for systems composed of hexane, water, and 2-propanol. Certain ternary compositions were shown to be oil-continuous microemulsions, even though a soap or detergent was not present. Of a number of short-chain alcohols tested, only 2-propanol and 1-propanol could stabilize a microemulsified ternary solution. Addition of a small amount of hexadecyltrimethylammonium perchlorate to the ternary solutions produced only modest changes in the ternary phase diagram. However, in the presence of hexadecyltrimethylammonium salts, most short-chain alcohols containing less than eight carbons could stabilize an oil-continuous microemulsion.

References (21)

W.C Tosch et al.
J. Colloid Interface Sci
(1969)
A.W Adamson
J. Colloid Interface Sci
(1969)
S Friberg et al.
J. Colloid Interface Sci
(1969)
K Shinoda et al.
J. Colloid Interface Sci
(1973)
L.M Prince
J. Colloid Interface Sci
(1967)
L.M Prince
J. Colloid Interface Sci
(1969)
L.M Prince
J. Colloid Interface Sci
(1975)
K.J Mysels
J. Colloid Interface Sci
(1967)
T.P Hoar et al.
Nature (London)
(1943)
S.I Ahmed et al.
J. Colloid Interface Sci
(1974)

There are more references available in the full text version of this article.

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¹: Present address: Chemical Research Division, Research and Development Center, Continental Oil Company, Ponca City, Oklahoma 74601.

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Oil-continuous microemulsions composed of hexane, water, and 2-propanol

Abstract

J. Colloid Interface Sci

J. Colloid Interface Sci

J. Colloid Interface Sci

J. Colloid Interface Sci

J. Colloid Interface Sci

J. Colloid Interface Sci

J. Colloid Interface Sci

J. Colloid Interface Sci

Nature (London)

J. Colloid Interface Sci