Term: coalescence
https://doi.org/10.1351/goldbook.C01119

Definition:
The disappearance of the boundary between two particles (usually droplets or bubbles) in contact, or between one of these and a bulk phase followed by changes of shape leading to a reduction of the total surface area. The flocculation of an emulsion, viz. the formation of aggregates, may be followed by coalescence.

Related Terms:
1) flocculation (http://doi.org/10.1351/goldbook.A00182).
2) emulsion (http://doi.org/10.1351/goldbook.E02065).
3) aggregates (<em>in catalysis</em>) (http://doi.org/10.1351/goldbook.A00184).

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 610 (https://doi.org/10.1351/pac197231040577)

Citation: 'coalescence' in IUPAC Compendium of Chemical Terminology, 5th ed. International Union of Pure and Applied Chemistry; 2025. Online version 5.0.0, 2025. https://doi.org/10.1351/goldbook.C01119

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