Publication
Title
Multi-scale X-ray imaging of the pigment discoloration processes triggered by chlorine compounds in the Upper Basilica of Saint Francis of Assisi
Author
Abstract
In this paper, the chromatic alteration of various types of paints, present on mural painting fragments derived from the vaults of The Upper Basilica of Saint Francis of Assisi in Italy (12th-13th century), is studied using synchrotron radiation. Six painted mural fragments, several square centimeters in size, were available for analysis, originating from the ceiling paintings attributed to Cimabue and Giotto; they correspond to originally white, blue/green, and brown/yellow/orange areas showing discoloration. As well as collecting macroscopic X-ray fluorescence and diffraction maps from the entire fragments in the laboratory and at the SOLEIL synchrotron, corresponding paint cross-sections were also analyzed using microscopic X-ray fluorescence and powder diffraction mapping at the PETRA-III synchrotron. Numerous secondary products were observed on the painted surfaces, such as (a) copper tri-hydroxychloride in green/blue areas; (b) corderoite and calomel in vermillion red/cinnabar-rich paints; (c) plattnerite and/or scrutinyite assumed to be oxidation products of (hydro)cerussite (2PbCO(3)center dot Pb(OH)(2)) in the white areas, and (d) the calcium oxalates whewellite and weddellite. An extensive presence of chlorinated metal salts points to the central role of chlorine-containing compounds during the degradation of the 800-year-old paint, leading to, among other things, the formation of the rare mineral cumengeite (21PbCl(2)center dot 20Cu(OH) (2) center dot 6H(2)O).
Language
English
Source (journal)
Molecules: a journal of synthetic chemistry and natural product chemistry. - Bazel
Publication
Bazel : 2023
ISSN
1420-3049
DOI
10.3390/MOLECULES28166106
Volume/pages
28 :16 (2023) , p. 1-23
Article Reference
6106
ISI
001056388600001
Pubmed ID
37630361
Medium
E-only publicatie
Full text (Publisher's DOI)
Full text (open access)
UAntwerpen
Faculty/Department
Research group
Project info
Fusing microscopic and nanoscopic 3D data with macroscopic 2D mapping information for a better understanding of paint degradation phenomena in 17th. century masterpieces
Publication type
Subject
Affiliation
Publications with a UAntwerp address
External links
Web of Science
Record
Identifier
Creation 02.10.2023
Last edited 25.04.2024
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