Saved in:
| Main Authors: | , , |
|---|---|
| Format: | Preprint |
| Published: |
2025
|
| Subjects: | |
| Online Access: | https://arxiv.org/abs/2505.14248 |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| _version_ | 1866912515511812096 |
|---|---|
| author | Vaisleib, Noy Arbel-Haddad, Michal Goldbourt, Amir |
| author_facet | Vaisleib, Noy Arbel-Haddad, Michal Goldbourt, Amir |
| contents | Geopolymers are aluminosilicate materials that exhibit effective immobilization properties for low-level radioactive nuclear waste, and more specifically for the immobilization of radioactive cesium. The identification of the cesium-binding sites and their distribution between the different phases making up the geopolymeric matrix can be obtained using solid-state NMR measurements of the quadrupolar spin 133Cs, which is a surrogate for the radioactive cesium species present in nuclear waste streams. For quadrupolar nuclei, acquiring two-dimensional multiple-quantum experiments allows the acquisition of more dispersed spectra when multiple sites overlap. However, 133Cs has a spin-7/2 and one of the smallest quadrupole moments, making multiple-quantum excitation highly challenging. In this work we present pulse schemes that enhance the excitation efficiency of 133Cs triple quantum coherences by a factor of ~2 with respect to a two-pulse excitation scheme. The improved schemes were developed by using numerical simulation and verified experimentally by applying one and two-dimensional triple-quantum solid-state NMR experiments to a mixture of cesium-exchanged hydrated zeolites A and X, which possess dynamically averaged small quadrupolar coupling constants in the order of 10 kHz. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2505_14248 |
| institution | arXiv |
| publishDate | 2025 |
| record_format | arxiv |
| spellingShingle | Enhanced 133cs Triple-Quantum Excitation in Solid-State NMR of Cs-Bearing Zeolites Vaisleib, Noy Arbel-Haddad, Michal Goldbourt, Amir Chemical Physics Geopolymers are aluminosilicate materials that exhibit effective immobilization properties for low-level radioactive nuclear waste, and more specifically for the immobilization of radioactive cesium. The identification of the cesium-binding sites and their distribution between the different phases making up the geopolymeric matrix can be obtained using solid-state NMR measurements of the quadrupolar spin 133Cs, which is a surrogate for the radioactive cesium species present in nuclear waste streams. For quadrupolar nuclei, acquiring two-dimensional multiple-quantum experiments allows the acquisition of more dispersed spectra when multiple sites overlap. However, 133Cs has a spin-7/2 and one of the smallest quadrupole moments, making multiple-quantum excitation highly challenging. In this work we present pulse schemes that enhance the excitation efficiency of 133Cs triple quantum coherences by a factor of ~2 with respect to a two-pulse excitation scheme. The improved schemes were developed by using numerical simulation and verified experimentally by applying one and two-dimensional triple-quantum solid-state NMR experiments to a mixture of cesium-exchanged hydrated zeolites A and X, which possess dynamically averaged small quadrupolar coupling constants in the order of 10 kHz. |
| title | Enhanced 133cs Triple-Quantum Excitation in Solid-State NMR of Cs-Bearing Zeolites |
| topic | Chemical Physics |
| url | https://arxiv.org/abs/2505.14248 |