Gizatullin, Bulat ; Mattea, Carlos ; Stapf, Siegfried ; Wissel, Till ; Buntkowsky, Gerd (2024)
NMR Relaxation Dispersion of Liquids Adsorbed on Modified Surfaces of SBA-15 Mesoporous Silica.
In: The Journal of Physical Chemistry C, 128 (21)
doi: 10.1021/acs.jpcc.4c00645
Artikel, Bibliographie
Dies ist die neueste Version dieses Eintrags.
Kurzbeschreibung (Abstract)
The NMR relaxation dispersion of ¹H and ²H nuclei in water and alkanes was studied in mesoporous SBA-15 silica in its native state and with modified internal surfaces. By comparison with silica gel of comparable characteristic pore size, a qualitative agreement of the relaxation dispersion was found. In the absence of detectable amounts of paramagnetic centers, intramolecular relaxation is approximated by the model of Reorientations Mediated by Translational Displacements (RMTD), which assumes rigid molecules diffusing along curved surfaces and experiencing long-term memory of their relative orientation due to their polarity. For all liquids, significant relaxation dispersion is found so that the vanishing polarity of alkanes does not allow the assumption of a negligible surface interaction. The difference in dispersion shape between ¹H and ²H nuclei, relaxing by dipolar and quadrupolar mechanisms, respectively, allows the reconstruction of the intermolecular contribution to relaxation, which has not yet been studied systematically in porous media. A model based on the relative contributions of intra- and intermolecular interactions as well as hydrogen exchange with OH- and NH₂-groups is presented.
| Typ des Eintrags: | Artikel |
|---|---|
| Erschienen: | 2024 |
| Autor(en): | Gizatullin, Bulat ; Mattea, Carlos ; Stapf, Siegfried ; Wissel, Till ; Buntkowsky, Gerd |
| Art des Eintrags: | Bibliographie |
| Titel: | NMR Relaxation Dispersion of Liquids Adsorbed on Modified Surfaces of SBA-15 Mesoporous Silica |
| Sprache: | Englisch |
| Publikationsjahr: | 15 Mai 2024 |
| Ort: | Washington D.C. |
| Verlag: | American Chemical Society |
| Titel der Zeitschrift, Zeitung oder Schriftenreihe: | The Journal of Physical Chemistry C |
| Jahrgang/Volume einer Zeitschrift: | 128 |
| (Heft-)Nummer: | 21 |
| DOI: | 10.1021/acs.jpcc.4c00645 |
| Zugehörige Links: | |
| Kurzbeschreibung (Abstract): | The NMR relaxation dispersion of ¹H and ²H nuclei in water and alkanes was studied in mesoporous SBA-15 silica in its native state and with modified internal surfaces. By comparison with silica gel of comparable characteristic pore size, a qualitative agreement of the relaxation dispersion was found. In the absence of detectable amounts of paramagnetic centers, intramolecular relaxation is approximated by the model of Reorientations Mediated by Translational Displacements (RMTD), which assumes rigid molecules diffusing along curved surfaces and experiencing long-term memory of their relative orientation due to their polarity. For all liquids, significant relaxation dispersion is found so that the vanishing polarity of alkanes does not allow the assumption of a negligible surface interaction. The difference in dispersion shape between ¹H and ²H nuclei, relaxing by dipolar and quadrupolar mechanisms, respectively, allows the reconstruction of the intermolecular contribution to relaxation, which has not yet been studied systematically in porous media. A model based on the relative contributions of intra- and intermolecular interactions as well as hydrogen exchange with OH- and NH₂-groups is presented. |
| Freie Schlagworte: | Colloids, Liquids, Molecular modeling, Molecules, Silica |
| Sachgruppe der Dewey Dezimalklassifikatin (DDC): | 500 Naturwissenschaften und Mathematik > 530 Physik 500 Naturwissenschaften und Mathematik > 540 Chemie |
| Fachbereich(e)/-gebiet(e): | 07 Fachbereich Chemie 07 Fachbereich Chemie > Eduard Zintl-Institut 07 Fachbereich Chemie > Eduard Zintl-Institut > Fachgebiet Physikalische Chemie |
| Hinterlegungsdatum: | 04 Okt 2024 07:11 |
| Letzte Änderung: | 17 Okt 2024 09:25 |
| PPN: | 522291775 |
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| Suche nach Titel in: | TUfind oder in Google |
Verfügbare Versionen dieses Eintrags
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NMR Relaxation Dispersion of Liquids Adsorbed on Modified Surfaces of SBA-15 Mesoporous Silica. (deposited 30 Sep 2024 12:20)
- NMR Relaxation Dispersion of Liquids Adsorbed on Modified Surfaces of SBA-15 Mesoporous Silica. (deposited 04 Okt 2024 07:11) [Gegenwärtig angezeigt]
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