{"term":{"id":"01704","doi":"10.1351\/goldbook.D01704","code":"D01704","status":"current","longtitle":"IUPAC Gold Book - differential diffusion coefficient","title":"differential diffusion coefficient","contains":"limiting differential diffusion coefficient","termversion":"2.3.3","lastupdated":"2014-02-24","definitions":[{"id":"1","text":"Defined by Di = -Ji\/∇ci is the amount of species i flowing through unit area in unit time and ∇ci is the concentration gradient of species i. Different diffusion coefficients may be defined depending on the choice of the frame of reference used for Ji and ∇ci. For systems with more than two components, the flow of any component and hence its diffusion coefficient depends on the concentration distribution of all components. The limiting differential diffusion coefficient is the value of Di extrapolated to zero concentration of the diffusing species: ","links":[{"title":"concentration gradient","type":"goldify","url":"https:\/\/goldbook.iupac.org\/terms\/view\/C01227"},{"title":"diffusion","type":"goldify","url":"https:\/\/goldbook.iupac.org\/terms\/view\/D01716"},{"title":"diffusion coefficient","type":"goldify","url":"https:\/\/goldbook.iupac.org\/terms\/view\/D01719"}],"math":[{"alttext":"Di = -Ji\/∇ci","latex":"D_{i} = \\frac{-J_{i}}{\\nabla c_{i}}"},{"alttext":"Ji","latex":"J_{i}"},{"alttext":"i","latex":"i"},{"type":"quantity","alttext":"∇ci","latex":"\\nabla c_{i}"},{"alttext":"i","latex":"i"},{"alttext":"Ji","latex":"J_{i}"},{"alttext":"∇ci","latex":"\\nabla c_{i}"},{"alttext":"Di","latex":"D_{i}"},{"type":"equation","alttext":"[Di] = lim(ci→0) Di","latex":"[D_{i}]=\\lim _{c_{i}\\rightarrow 0}D_{i}"}],"sources":["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 617 (https:\/\/doi.org\/10.1351\/pac197231040577)"]}],"links":{"html":"https:\/\/goldbook.iupac.org\/terms\/view\/D01704\/html","json":"https:\/\/goldbook.iupac.org\/terms\/view\/D01704\/json","xml":"https:\/\/goldbook.iupac.org\/terms\/view\/D01704\/xml","plain":"https:\/\/goldbook.iupac.org\/terms\/view\/D01704\/plain","pdf":"https:\/\/goldbook.iupac.org\/terms\/view\/D01704\/pdf"},"citation":"Citation: 'differential diffusion coefficient' in IUPAC Compendium of Chemical Terminology, 3rd ed. International Union of Pure and Applied Chemistry; 2006. Online version 3.0.1, 2019. 10.1351\/goldbook.D01704","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":"2023-12-08T05:44:32+00:00"}}