{"term":{"id":"03823","title":"membrane","longtitle":"IUPAC Gold Book - membrane","doi":"10.1351\/goldbook.M03823","code":"M03823","status":"current","definitions":[{"id":1,"text":"A general term which refers to a continuous layer, usually consisting of a semi-permeable material, with controlled permeability covering a structure, such as carbon or an inert metal, or separating two electrolyte solutions. This latter case is the most general form of an ion-selective electrode. The membrane separates the internal components of the ion-selective electrode from the test solution. The membrane of an ion-selective electrode is responsible for the EMF response and selectivity of the entire electrode. Comment: Membranes of sensor electrodes are thought to be practically homogeneous, but an actual membrane may contain inhomogeneous regions, often at surfaces, and connected with materials and preparation methods used. Inhomogeneous regions include low dielectric polymer regions with few charge sites and regions with high local site densities. Surface regions of plasticized liquid membranes often are low in sites and high in plasticizer or exuded impurities.","contexts":[],"links":[{"term":"inert","url":"https:\/\/goldbook.iupac.org\/\/terms\/view\/I03026"},{"term":"ion-selective electrode","url":"https:\/\/goldbook.iupac.org\/\/terms\/view\/I03244"},{"term":"membrane","url":"https:\/\/goldbook.iupac.org\/\/terms\/view\/MT06878"},{"term":"permeability","url":"https:\/\/goldbook.iupac.org\/\/terms\/view\/P04503"},{"term":"selectivity","url":"https:\/\/goldbook.iupac.org\/\/terms\/view\/S05563"}],"sources":["PAC, 1994, 66, 2527. 'Recommendations for nomenclature of ionselective electrodes (IUPAC Recommendations 1994)' on page 2531 (https:\/\/doi.org\/10.1351\/pac199466122527)"]}],"altoutputs":{"html":"https:\/\/goldbook.iupac.org\/terms\/view\/M03823\/html","xml":"https:\/\/goldbook.iupac.org\/terms\/view\/M03823\/xml","plain":"https:\/\/goldbook.iupac.org\/terms\/view\/M03823\/plain"},"citation":"Citation: 'membrane' 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.M03823","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.","collection":"If you are interested in licensing the Gold Book for commercial use, please contact the IUPAC Executive Director at executivedirector@iupac.org .","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.","accessed":"2026-07-30T17:37:34+00:00"}}