Anomalous translational diffusive processes in hydrogen-bonded systems investigated by ultrasonic technique, Raman scattering and NMR
| Autor: | Caterina Branca, Salvatore Magazù, E. Tettamanti, Giacomo Maisano, P. Migliardo |
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| Rok vydání: | 2000 |
| Předmět: |
Aqueous solution
Materials science Hydrogen bond Diffusion Concentration effect Nuclear magnetic resonance spectroscopy Condensed Matter Physics Electronic Optical and Magnetic Materials Microviscosity symbols.namesake Nuclear magnetic resonance Chemical physics symbols Electrical and Electronic Engineering Hydrodynamic theory Raman scattering |
| Zdroj: | Physica B: Condensed Matter. 291:180-189 |
| ISSN: | 0921-4526 |
| DOI: | 10.1016/s0921-4526(99)01384-8 |
| Popis: | Ultrasonic technique, Raman scattering and NMR spectroscopy are employed to study the structural and dynamical properties of aqueous solutions of α,α-trehalose, at different temperature and concentration values. What emerges is that trehalose, whose hydration number keeps almost constant with temperature, shows a destructuring effect on the tetrahedral network of water. The outstanding feature of this result is that trehalose, by such a destructuring effect, reduces the microviscosity experienced by the diffusive entities. This is confirmed by a test of the Stokes–Einstein relation, where an anomalous translational diffusive process, consisting in an enhanced diffusion with respect to that predicted by hydrodynamic theory under stick conditions, is revealed. This latter finding, connected with the presence of strong solute–solvent interactions, supports the role of trehalose as a structure-breaker. |
| Databáze: | OpenAIRE |
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