For an
interface, the adsorption or surface excess of a given component is defined as the difference
between the amount of component actually present in the system, and that which would
be present (in a reference system) if the bulk concentration in the adjoining phases
were maintained up to a chosen geometrical
dividing surface (
Gibbs dividing surface). For a solid/liquid
interface in which no component of the liquid phase penetrates into the solid, the surface
excess (or adsorption) of component
i is defined as:
where
is the total amount of
i in the system,
is the volume of an arbitrarily chosen amount of bulk liquid (in the framework of
the so-called algebraic method) and
is its bulk concentration in the liquid.
Source:
PAC, 1986, 58, 967
(Reporting data on adsorption from solution at the solid/solution interface (Recommendations
1986))
on page 969
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.
