Unified Approach to Ion Transport and Structural Relaxation in Amorphous Polymers and Glasses
Kinetic data for structural relaxation in silver iodomolybdates at the glass transition temperature (T g) are obtained by high-pressure differential scanning calorimetry (HP-DSC) and are compared with activation energies (E A) and volumes (V A) obtained earlier from conductivities below T g. The res...
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Published in | The journal of physical chemistry. B Vol. 112; no. 3; pp. 859 - 866 |
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Main Authors | , , , |
Format | Journal Article |
Language | English |
Published |
United States
American Chemical Society
24.01.2008
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Online Access | Get full text |
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Summary: | Kinetic data for structural relaxation in silver iodomolybdates at the glass transition temperature (T g) are obtained by high-pressure differential scanning calorimetry (HP-DSC) and are compared with activation energies (E A) and volumes (V A) obtained earlier from conductivities below T g. The results are fitted to an empirical equation, E A = MV A, and displayed in the form of a master plot of E A versus V A, an approach previously applied to strongly coupled systems, including polymer electrolytes and molten salts above their glass transition temperatures. The parameter M emerges as a localized modulus, expressive of interatomic forces within the medium, linking together E A, σ, V A, σ and E A,s, V A,s, the “apparent” activation parameters for ionic conductivity and structural relaxation, respectively. The V A and E A values for ion transport are much smaller than the corresponding values for structural relaxation. However, remarkably close agreement emerges between the “process parameters”, M s and M σ, both close to 8 GPa, thus establishing a quantitative link between ion transport and structural relaxation in this highly decoupled system. A new E A versus V A master plot is constructed, which points the way to a unified approach to ion transport in polymers and glasses. |
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Bibliography: | istex:D7E8345F512DDF291A9DEF69D1728E7BDED07D9D ark:/67375/TPS-4J8BHDT3-P ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 |
ISSN: | 1520-6106 1520-5207 |
DOI: | 10.1021/jp0754482 |