Single-Sided Portable NMR Investigation to Assess and Monitor Cleaning Action of PVA-Borax Hydrogel in Travertine and Lecce Stone
In this work, we investigated the potential of PVA-borax hydrogel for cleaning limestones and the dependence of the cleaning on the porosity of the rock and on the action time of the hydrogel treatment. Towards this goal, we used a nuclear magnetic resonance (NMR) spectrometer, developed for non-inv...
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| Format: | Article |
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MDPI AG
2021-06-01
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| Series: | Molecules |
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| Online Access: | https://www.mdpi.com/1420-3049/26/12/3697 |
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| author | Valeria Stagno Chiara Genova Nicole Zoratto Gabriele Favero Silvia Capuani |
| author_facet | Valeria Stagno Chiara Genova Nicole Zoratto Gabriele Favero Silvia Capuani |
| author_sort | Valeria Stagno |
| collection | DOAJ |
| description | In this work, we investigated the potential of PVA-borax hydrogel for cleaning limestones and the dependence of the cleaning on the porosity of the rock and on the action time of the hydrogel treatment. Towards this goal, we used a nuclear magnetic resonance (NMR) spectrometer, developed for non-invasive and non-destructive applications on cultural heritage. <i>T</i><sub>2</sub>-NMR parameters were quantified on different samples of Lecce stone and Travertine cut perpendicular (Pe) and parallel (Pa) to the bedding planes under different experimental conditions: untreated samples, treated with Paraloid B72 and cleaned with PVA-PEO-borax hydrogel applied for 4 min and 2 h. The <i>T</i><sub>2</sub> results suggest that the effectiveness of the cleaning strongly depended on the porosity of the stones. In Lecce stone, the hydrogel seemed to eliminate both the paramagnetic impurities (in equal measure with 4 min and 2 h treatment) and Paraloid B72. In Travertine Pe, characterized by a smaller pore size compared to Lecce stone, no significant effects were found regarding both the cleaning and the treatment with Paraloid B72. In Travertine Pa, characterized by a larger pore size than the other two samples, the hydrogel seemed to clean the paramagnetic agents (it worked better if applied for a longer time) but it did not appear to have any effect on Paraloid B72 removal. |
| first_indexed | 2024-03-10T10:19:47Z |
| format | Article |
| id | doaj.art-b1ad69edc2ea437bbd7b41a7d9629f70 |
| institution | Directory Open Access Journal |
| issn | 1420-3049 |
| language | English |
| last_indexed | 2024-03-10T10:19:47Z |
| publishDate | 2021-06-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Molecules |
| spelling | doaj.art-b1ad69edc2ea437bbd7b41a7d9629f702023-11-22T00:30:21ZengMDPI AGMolecules1420-30492021-06-012612369710.3390/molecules26123697Single-Sided Portable NMR Investigation to Assess and Monitor Cleaning Action of PVA-Borax Hydrogel in Travertine and Lecce StoneValeria Stagno0Chiara Genova1Nicole Zoratto2Gabriele Favero3Silvia Capuani4Earth Sciences Department, Sapienza University of Rome, Piazzale Aldo Moro 5, 00185 Rome, ItalyDepartment of Chemistry and Drug Technologies, Sapienza University of Rome, Piazzale Aldo Moro 5, 00185 Rome, ItalyDepartment of Chemistry and Drug Technologies, Sapienza University of Rome, Piazzale Aldo Moro 5, 00185 Rome, ItalyDepartment of Chemistry and Drug Technologies, Sapienza University of Rome, Piazzale Aldo Moro 5, 00185 Rome, ItalyNational Research Council Institute for Complex Systems (CNR-ISC) c/o Physics Department, Sapienza University of Rome, Piazzale Aldo Moro 5, 00185 Rome, ItalyIn this work, we investigated the potential of PVA-borax hydrogel for cleaning limestones and the dependence of the cleaning on the porosity of the rock and on the action time of the hydrogel treatment. Towards this goal, we used a nuclear magnetic resonance (NMR) spectrometer, developed for non-invasive and non-destructive applications on cultural heritage. <i>T</i><sub>2</sub>-NMR parameters were quantified on different samples of Lecce stone and Travertine cut perpendicular (Pe) and parallel (Pa) to the bedding planes under different experimental conditions: untreated samples, treated with Paraloid B72 and cleaned with PVA-PEO-borax hydrogel applied for 4 min and 2 h. The <i>T</i><sub>2</sub> results suggest that the effectiveness of the cleaning strongly depended on the porosity of the stones. In Lecce stone, the hydrogel seemed to eliminate both the paramagnetic impurities (in equal measure with 4 min and 2 h treatment) and Paraloid B72. In Travertine Pe, characterized by a smaller pore size compared to Lecce stone, no significant effects were found regarding both the cleaning and the treatment with Paraloid B72. In Travertine Pa, characterized by a larger pore size than the other two samples, the hydrogel seemed to clean the paramagnetic agents (it worked better if applied for a longer time) but it did not appear to have any effect on Paraloid B72 removal.https://www.mdpi.com/1420-3049/26/12/3697NMRrelaxation time <i>T</i><sub>2</sub>single-sided NMRhydrogelcleaningParaloid B72 |
| spellingShingle | Valeria Stagno Chiara Genova Nicole Zoratto Gabriele Favero Silvia Capuani Single-Sided Portable NMR Investigation to Assess and Monitor Cleaning Action of PVA-Borax Hydrogel in Travertine and Lecce Stone Molecules NMR relaxation time <i>T</i><sub>2</sub> single-sided NMR hydrogel cleaning Paraloid B72 |
| title | Single-Sided Portable NMR Investigation to Assess and Monitor Cleaning Action of PVA-Borax Hydrogel in Travertine and Lecce Stone |
| title_full | Single-Sided Portable NMR Investigation to Assess and Monitor Cleaning Action of PVA-Borax Hydrogel in Travertine and Lecce Stone |
| title_fullStr | Single-Sided Portable NMR Investigation to Assess and Monitor Cleaning Action of PVA-Borax Hydrogel in Travertine and Lecce Stone |
| title_full_unstemmed | Single-Sided Portable NMR Investigation to Assess and Monitor Cleaning Action of PVA-Borax Hydrogel in Travertine and Lecce Stone |
| title_short | Single-Sided Portable NMR Investigation to Assess and Monitor Cleaning Action of PVA-Borax Hydrogel in Travertine and Lecce Stone |
| title_sort | single sided portable nmr investigation to assess and monitor cleaning action of pva borax hydrogel in travertine and lecce stone |
| topic | NMR relaxation time <i>T</i><sub>2</sub> single-sided NMR hydrogel cleaning Paraloid B72 |
| url | https://www.mdpi.com/1420-3049/26/12/3697 |
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