12255 IUPAC Gold Book - impermeable 10.1351/goldbook.12255 12255 current synonym: non-free-draining 1 Adjective describing the flow behaviour of a macromolecule in solution or a dispersed entity when, due to hydrodynamic interaction, the solvent or dispersion medium within the domain of the macromolecule or dispersed entity is essentially immobilised and moves with the dissolved macromolecule or dispersed entity. hydrodynamic interaction https://goldbook.iupac.org//terms/view/12253 PAC, 2015, 87, 71. 'Definitions of terms relating to individual macromolecules, macromolecular assemblies, polymer solutions, and amorphous bulk polymers (IUPAC Recommendations 2014)' on page 102 (https://doi.org/10.1515/pac-2013-0201) https://goldbook.iupac.org/terms/view/12255/html https://goldbook.iupac.org/terms/view/12255/json https://goldbook.iupac.org/terms/view/12255/plain Citation: 'impermeable' 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.12255 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. 2026-04-18T01:47:48+00:00