Term: inverted micelle
https://doi.org/10.1351/goldbook.I03151

Definition:
The reversible formation of association colloids from surfactants in non-polar solvents leads to aggregates termed inverted (or inverse, reverse or reversed) micelle. Such association is often of the type: \[\text{Monomer}\rightleftarrows \text{Dimer}\rightleftarrows \text{Trimer}\rightleftarrows \text{ ... }n\text{-mer}\] and the phenomenon of critical micelle concentration (or an analogous effect) is consequently not observed. In an inverted micelle the polar groups of the surfactants are concentrated in the interior and the lipophilic groups extend towards and into the non-polar solvent.

Related Terms:
1) association (http://doi.org/10.1351/goldbook.A00472).
2) micelle (http://doi.org/10.1351/goldbook.M03889).
3) polar solvent (http://doi.org/10.1351/goldbook.P04717).
4) critical micelle concentration (http://doi.org/10.1351/goldbook.C01395).
5) lipophilic (http://doi.org/10.1351/goldbook.L03572).

Source: PAC, 1994, 66, 1077. 'Glossary of terms used in physical organic chemistry (IUPAC Recommendations 1994)' on page 1126 (https://doi.org/10.1351/pac199466051077)

Citation: 'inverted micelle' 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.I03151

License: The IUPAC Gold Book is licensed under Creative Commons Attribution-ShareAlike CC BY-SA 4.0 International (https://creativecommons.org/licenses/by-sa/4.0/) for individual terms.

Disclaimer: The International Union of Pure and Applied Chemistry (IUPAC) is continuously reviewing and, where needed, updating terms in the Compendium of Chemical Terminology (the IUPAC Gold Book). Users of these terms are encouraged to include the version of a term with its use and to check regularly for updates to term definitions that you are using.