Brodrecht, Martin ; Klotz, Edda ; Lederle, Christina ; Breitzke, Hergen ; Stühn, Bernd ; Vogel, Michael ; Buntkowsky, Gerd (2021)
A Combined Solid-State NMR, Dielectric Spectroscopy and Calorimetric Study of Water in Lowly Hydrated MCM-41 Samples.
In: Zeitschrift für Physikalische Chemie, 2018, 232 (7-8)
doi: 10.26083/tuprints-00019681
Artikel, Zweitveröffentlichung, Verlagsversion
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Kurzbeschreibung (Abstract)
The processes of drying mesoporous silica materials and their refilling with water have been examined by magic-angle spinning (MAS) solid-state NMR, broadband dielectric spectroscopy (BDS), and differential scanning calorimetry (DSC). It is shown that different drying protocols strongly influence the amount and types of hydroxy-species inside the pores. It is found that a very good vacuum (≈10−6 bar) is necessary to remove all H₂O molecules from the silica matrices in order to accurately refill them with very low amounts of water such as e.g. a mono- or submonolayer coverage of the surface. Time-dependent ¹H-NMR-spectra recorded after loading the samples indicate a very specific course of water first existing in a bulk-like form inside the pores and then distributing itself through the pores by hydrogen bonding to surface silanol groups. After assuring accurate sample loading, we were able to investigate lowly hydrated samples of water confined in MCM-41 via DCS and BDS at temperatures below the freezing point of free bulk-water (0°C) and find two non-crystallizing water species with Arrhenius behavior and activation energies of 0.53 eV (51.1 kJ/mol).
| Typ des Eintrags: | Artikel |
|---|---|
| Erschienen: | 2021 |
| Autor(en): | Brodrecht, Martin ; Klotz, Edda ; Lederle, Christina ; Breitzke, Hergen ; Stühn, Bernd ; Vogel, Michael ; Buntkowsky, Gerd |
| Art des Eintrags: | Zweitveröffentlichung |
| Titel: | A Combined Solid-State NMR, Dielectric Spectroscopy and Calorimetric Study of Water in Lowly Hydrated MCM-41 Samples |
| Sprache: | Englisch |
| Publikationsjahr: | 2021 |
| Publikationsdatum der Erstveröffentlichung: | 2018 |
| Verlag: | De Gruyter |
| Titel der Zeitschrift, Zeitung oder Schriftenreihe: | Zeitschrift für Physikalische Chemie |
| Jahrgang/Volume einer Zeitschrift: | 232 |
| (Heft-)Nummer: | 7-8 |
| DOI: | 10.26083/tuprints-00019681 |
| URL / URN: | https://tuprints.ulb.tu-darmstadt.de/19681 |
| Zugehörige Links: | |
| Herkunft: | Zweitveröffentlichungsservice |
| Kurzbeschreibung (Abstract): | The processes of drying mesoporous silica materials and their refilling with water have been examined by magic-angle spinning (MAS) solid-state NMR, broadband dielectric spectroscopy (BDS), and differential scanning calorimetry (DSC). It is shown that different drying protocols strongly influence the amount and types of hydroxy-species inside the pores. It is found that a very good vacuum (≈10−6 bar) is necessary to remove all H₂O molecules from the silica matrices in order to accurately refill them with very low amounts of water such as e.g. a mono- or submonolayer coverage of the surface. Time-dependent ¹H-NMR-spectra recorded after loading the samples indicate a very specific course of water first existing in a bulk-like form inside the pores and then distributing itself through the pores by hydrogen bonding to surface silanol groups. After assuring accurate sample loading, we were able to investigate lowly hydrated samples of water confined in MCM-41 via DCS and BDS at temperatures below the freezing point of free bulk-water (0°C) and find two non-crystallizing water species with Arrhenius behavior and activation energies of 0.53 eV (51.1 kJ/mol). |
| Status: | Verlagsversion |
| URN: | urn:nbn:de:tuda-tuprints-196818 |
| Zusätzliche Informationen: | Keywords: broadband dielectric spectroscopy; confinement; solid-state NMR; water; wetting |
| Sachgruppe der Dewey Dezimalklassifikatin (DDC): | 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: | 01 Okt 2021 11:22 |
| Letzte Änderung: | 03 Jul 2024 02:32 |
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| Suche nach Titel in: | TUfind oder in Google |
Verfügbare Versionen dieses Eintrags
- A Combined Solid-State NMR, Dielectric Spectroscopy and Calorimetric Study of Water in Lowly Hydrated MCM-41 Samples. (deposited 01 Okt 2021 11:22) [Gegenwärtig angezeigt]
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