Diffusion-viscosity decoupling in supercooled glycerol aqueous solutions
The diffusion of ferrocene methanol in supercooled glycerol-water mixtures has been measured over a wide viscosity range, which allowed analyzing the composition dependence of the Stokes-Einstein breakdown (diffusion-viscosity decoupling). The observed decoupling exhibits a common behavior for all s...
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| Autores principales: | , |
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2015
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| Acceso en línea: | https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_15206106_v119_n1_p257_TrejoGonzalez http://hdl.handle.net/20.500.12110/paper_15206106_v119_n1_p257_TrejoGonzalez |
| Aporte de: |
| Sumario: | The diffusion of ferrocene methanol in supercooled glycerol-water mixtures has been measured over a wide viscosity range, which allowed analyzing the composition dependence of the Stokes-Einstein breakdown (diffusion-viscosity decoupling). The observed decoupling exhibits a common behavior for all studied compositions (glycerol mass fractions between 0.7 and 0.9), determined by the reduced temperature (T/Tg) of the mixtures. This result differs from that reported previously for the diffusion of glycerol in its aqueous solutions, where the reduced temperature for the decoupling decreases with increasing water content. We conclude that the contradictory results are only apparent, and they can be explained by the use of inconsistent extrapolated values of the viscosity of the glycerol-water mixtures in the supercooled region. (Figure Presented). © 2014 American Chemical Society. |
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