06172 IUPAC Gold Book - surface excess concentration 10.1351/goldbook.S06172 S06172 current quantity 1 A quantity defined by \[\mathit{\Gamma}_{i} = \frac{n_{i}^{\sigma }}{A_{\rm{s}}}\] where \(n_{i}^{\sigma}\) is the surface excess (or adsorption) of component \(i\) and \(A_{\rm{s}}\) is the area of the dividing surface or interface. adsorption https://goldbook.iupac.org//terms/view/A00155 dividing surface https://goldbook.iupac.org//terms/view/D01823 interface https://goldbook.iupac.org//terms/view/I03082 surface excess https://goldbook.iupac.org//terms/view/S06171 Green Book, 2nd ed., p. 63 (https://goldbook.iupac.org/files/pdf/green_book_2ed.pdf) PAC, 1986, 58, 967. 'Reporting data on adsorption from solution at the solid/solution interface (Recommendations 1986)' on page 970 (https://doi.org/10.1351/pac198658070967) https://goldbook.iupac.org/terms/view/S06172/html https://goldbook.iupac.org/terms/view/S06172/json https://goldbook.iupac.org/terms/view/S06172/plain Citation: 'surface excess concentration' in IUPAC Compendium of Chemical Terminology, 5th ed. International Union of Pure and Applied Chemistry; 2025. Online version 5.0.0, 2025. 10.1351/goldbook.S06172 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. If you are interested in licensing the Gold Book for commercial use, please contact the IUPAC Executive Director at executivedirector@iupac.org . 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. 2026-05-01T12:48:07+00:00