{"term":{"id":"02270","doi":"10.1351\/goldbook.E02270","code":"E02270","status":"current","longtitle":"IUPAC Gold Book - expansion factor, in polymers","title":"expansion factor","termversion":null,"lastupdated":null,"definitions":[{"id":"1","text":"The ratio of a dimensional characteristic of a macromolecule in a given solvent at a given temperature to the same dimensional characteristic in the θ state at the same temperature. The most frequently used expansion factors are: expansion factor of the mean-square end-to-end distance, αr = sqrt(\/o); expansion factor of the radius of gyrationαs = sqrt(\/o); viscosity expansion factor αη = ([η]\/[η]θ)1\/3 where [η] and [η]θ are the intrinsic viscosity in a given solvent and in the θ state at the same temperature, respectively. Expansion factors defined by different dimensional characteristics are not exactly equal, nor need they have a constant ratio as a function of relative molecular mass.","contexts":{"in":["polymers"]},"links":[{"title":"radius of gyration","type":"internal","url":"https:\/\/dev.goldbook.iupac.org\/terms\/view\/R05121"},{"title":"viscosity","type":"internal","url":"https:\/\/dev.goldbook.iupac.org\/terms\/view\/V06627"},{"title":"relative molecular mass","type":"internal","url":"https:\/\/dev.goldbook.iupac.org\/terms\/view\/R05271"}],"math":[{"alttext":"θ","latex":"\\unicode[Times]{x3B8}"},{"type":"equation","alttext":"αr = sqrt(\/o)","latex":"\\alpha _{r} = \\sqrt{\\frac{ < r^{2} > }{< r^{2} >_{0}}}"},{"type":"equation","alttext":"αs = sqrt(\/o)","latex":"\\alpha _{s} = \\sqrt{\\frac{ < s^{2} > }{ < s^{2} >_{0}}}"},{"type":"equation","alttext":"αη = ([η]\/[η]θ)1\/3","latex":"\\alpha _{\\eta } = (\\frac{\\left[\\eta \\right]}{\\left[\\eta \\right]_{\\unicode[Times]{x3B8} }})^{\\frac{1}{3}}"},{"type":"quantity","alttext":"[η]","latex":"[\\eta]"},{"type":"quantity","alttext":"[η]θ","latex":"[\\eta]_{\\unicode[Times]{x3B8}}"},{"alttext":"θ","latex":"\\unicode[Times]{x3B8}"}],"sources":["Purple Book, 1st ed., p. 59 (http:\/\/old.iupac.org\/publications\/books\/author\/metanomski.html)"]}],"links":{"html":"https:\/\/dev.goldbook.iupac.org\/terms\/view\/E02270\/html","json":"https:\/\/dev.goldbook.iupac.org\/terms\/view\/E02270\/json","xml":"https:\/\/dev.goldbook.iupac.org\/terms\/view\/E02270\/xml","plain":"https:\/\/dev.goldbook.iupac.org\/terms\/view\/E02270\/plain","pdf":"https:\/\/dev.goldbook.iupac.org\/terms\/view\/E02270\/pdf"},"citation":"Citation: 'expansion factor' 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.E02270","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":"2024-10-10T10:03:55+00:00"}}