An aggregate of a small number of atoms, molecules or ions. An embryo of such a size
that the Gibbs energy at constant pressure and temperature is a maximum is called
a critical embryo. An embryo larger than a critical embryo is called a homogeneous
nucleus.
Colloidal sols may be formed by condensation methods. When a condensation method is applied, molecules
(or ions) are deposited on nuclei which may be of the same chemical species as the
colloid (
homogeneous nucleation) or different (
heterogeneous nucleation).
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 608
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.
