Application of proton field-cycling NMR relaxometry for studying translational diffusion in simple liquids and polymer melts
© 2019 John Wiley & Sons, Ltd.
| Veröffentlicht in: | Magnetic resonance in chemistry : MRC. - 1985. - 57(2019), 10 vom: 24. Aug., Seite 805-817 |
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| Weitere Verfasser: | , , |
| Format: | Online-Aufsatz |
| Sprache: | English |
| Veröffentlicht: |
2019
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| Zugriff auf das übergeordnete Werk: | Magnetic resonance in chemistry : MRC |
| Schlagworte: | Journal Article Review Research Support, Non-U.S. Gov't field-cycling NMR polymers simple liquids translational diffusion |
| Zusammenfassung: | © 2019 John Wiley & Sons, Ltd. With the availability of commercial field-cycling relaxometers together with progress of home-built instruments nuclear magnetic resonance relaxometry has gained new momentum as a method of investigating the dynamics in viscous liquids and polymer melts. The method provides the frequency dependence of the spin-lattice relaxation rate. In the case of protons, one distinguishes intramolecular and intermolecular relaxation pathways. Whereas the intramolecular contribution prevails at high frequencies and reflects rotational dynamics, the often ignored intermolecular relaxation contribution dominates at low-frequency and provides access to translational dynamics. A universal low-frequencies dispersion law holds which in pure systems allows determining the diffusion coefficient in a straightforward way. In addition, the rotational time constant is extracted from the high-frequency relaxation contribution. This is demonstrated for simple and ionic liquids and for polymer melts |
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| Beschreibung: | Date Completed 22.10.2019 Date Revised 08.01.2020 published: Print-Electronic Citation Status PubMed-not-MEDLINE |
| ISSN: | 1097-458X |
| DOI: | 10.1002/mrc.4823 |