The property of surface activity is usually due to the fact that the molecules of
the substance are amphipathic or
amphiphilic, meaning that each contains both a
hydrophilic and a hydrophobic (
lipophilic) group. This assumes that one of the two phases is aqueous, and the other non-aqueous.
If both are non-aqueous (e.g. oil/air), molecules containing organophilic and organophobic
groups may be amphipathic and surface active.
Source:
PAC, 1972, 31, 577
(Manual of Symbols and Terminology for Physicochemical Quantities and Units, Appendix
II: Definitions, Terminology and Symbols in Colloid and Surface Chemistry)
on page 612
Cite as:
IUPAC. Compendium of Chemical Terminology, 2nd ed. (the "Gold Book"). Compiled by
A. D. McNaught and A. Wilkinson. Blackwell Scientific Publications, Oxford (1997).
XML on-line corrected version: http://goldbook.iupac.org (2006-) created by M. Nic,
J. Jirat, B. Kosata; updates compiled by A. Jenkins. ISBN 0-9678550-9-8.
https://doi.org/10.1351/goldbook.