Mudronja, Domagoj; Vanmeert, Frederik; Fazinić, Stjepko; Janssens, Koen; Tibljaš, Darko; Desnica, Vladan (2021) Protection of Stone Monuments Using a Brushing Treatment with Ammonium Oxalate. Coatings, 11 (4). ISSN 2079-6412
|
PDF
- Published Version
- article
Available under License Creative Commons Attribution. Download (1MB) | Preview |
Abstract
Stone monuments and buildings are susceptible to weathering. Carbonate-based stones are especially vulnerable in acidic environments, whereas magmatic acidic stones are more susceptible to chemical weathering in basic environments. To slow down surface corrosion of limestone and marble artworks/buildings, protective coatings which inhibit calcite dissolution have been proposed. In this work, samples from two stone types with different porosity were treated with ammonium oxalate (AmOx) to create a protective layer of calcium oxalate (CaOx) using the previously developed brushing method. Two different synchrotron microscopy experiments were performed to determine its protective capability. X-ray powder diffraction (SR-μ-XRPD) in transmission geometry allowed visualization of the distributions of calcium carbonate and oxalates along the sample depths. In a second step, X-ray fluorescence (SR-μ-XRF) was used to check the efficiency/integrity of the protective surface coating layer. This was done by measuring the sulfur distribution on the stone surface after exposing the protected stones to sulfuric acid. XRPD showed the formation of a protective oxalate layer with a thickness of 5–15 µm on the less porous stone, while a 20–30 µm thick layer formed on the more porous stone. The XRF study showed that the optimal treatment time depends on the stone porosity. Increasing the treatment time from 1 to 3 h resulted in a decreased efficiency of the protective layer for the low porosity stone. We assume that this is due to the formation of vertical channels (cracks) in the protective layer.
| Item Type: | Article | ||||||||
|---|---|---|---|---|---|---|---|---|---|
| Uncontrolled Keywords: | ammonium oxalate ; calcium oxalate ; stone monuments ; synchrotron based μXRD ; synchrotron based μXRF | ||||||||
| Subjects: | NATURAL SCIENCES > Interdisciplinary Natural Sciences SOCIAL SCIENCES > Interdisciplinary Social Sciences |
||||||||
| Divisions: | Division of Experimental Physics | ||||||||
| Projects: |
|
||||||||
| Depositing User: | Stjepko Fazinić | ||||||||
| Date Deposited: | 31 Dec 2021 09:30 | ||||||||
| URI: | http://fulir.irb.hr/id/eprint/6856 | ||||||||
| DOI: | 10.3390/coatings11040379 |
Actions (login required)
 |
View Item |
Altmetric
Altmetric
