Monico Letizia, Cartechini Laura, Rosi Francesca, De Nolf Wout, Cotte Marine, Vivani Riccardo, Maurich Celeste, Miliani Costanza
Analytical chemistry Characterization and analytical techniques calcium-based consolidants Article Imaging techniques Science Materials science Medicine Q R limestones Imaging studies [CHIM]Chemical Sciences 2D-XANES Multidisciplinary
In Heritage Science, the evaluation of stone consolidation treatments by investigating the nature of in situ newly formed products and their penetration depth within the consolidated matrix is a grand challenge. A number of analytical methods have been proposed, but, currently, most of them are not able to supply a full overview of the spatial, structural and compositional information of the newly formed crystalline and amorphous phases with a submicrometric lateral resolution. Here, we examined, the capabilities of synchrotron radiation (SR)-based two-dimensional X-ray absorption near-edge structure (2D-XANES) spectroscopy at Ca K-edge for determining the structural and compositional properties of the compounds formed after the application of a calcium acetoacetate-based consolidant on a porous carbonatic stone (limestone) and for investigating their stratigraphic distribution at the submicrometric scale length. We evaluated advantages and drawbacks of three Ca K-edge 2D-XANES-based approaches: (i) transmission mode full-field-XANES (FF-XANES) imaging; (ii) micro-X-ray fluorescence (mu -XRF) mapping above the Ca K-edge combined with the acquisition of XRF mode mu -XANES spectra at a limited number of spots; (iii) full-spectral mu -XANES (FS mu -XANES) mapping in XRF mode and its variant called selectively induced X-ray emission spectroscopy (SIXES) mapping. Overall, Ca K-edge 2D-XANES spectroscopy provided accurate qualitative and semi-quantitative information on the newly formed calcium carbonates (i.e., amorphous calcium carbonate, vaterite and calcite) and their stratigraphic distribution at the submicrometric scale, thus opening a new scenario to study the carbonatation process of calcium-based consolidants in limestones.
Source: Scientific reports (Nature Publishing Group) 10 (2020). doi:10.1038/s41598-020-71105-8
Publisher: Nature Publishing Group, London , Regno Unito
@article{oai:it.cnr:prodotti:433336, title = {Synchrotron radiation Ca K-edge 2D-XANES spectroscopy for studying the stratigraphic distribution of calcium-based consolidants applied in limestones}, author = {Monico Letizia and Cartechini Laura and Rosi Francesca and De Nolf Wout and Cotte Marine and Vivani Riccardo and Maurich Celeste and Miliani Costanza}, publisher = {Nature Publishing Group, London , Regno Unito}, doi = {10.1038/s41598-020-71105-8}, journal = {Scientific reports (Nature Publishing Group)}, volume = {10}, year = {2020} }