When a liquid does not spread on a
substrate (usually a solid), a contact
angle (
) is formed which is defined as the
angle between two of the interfaces at the three-phase line of contact. It must always be stated which interfaces are used to define
. It is often necessary to distinguish between the '
advancing contact angle'
(
), the '
receding contact angle'
(
) and the '
equilibrium contact angle'
(
).
When
the system is said to exhibit contact
angle hysteresis 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 598
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.
doi:10.1351/goldbook.
