Department of Chemistry, Materials and Chemical Engineering, Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133, Milan, Italy.
Department of Physics, Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133, Milan, Italy.
Sci Rep. 2023 Mar 25;13(1):4902. doi: 10.1038/s41598-023-31129-2.
This paper accounts for the diagnostic campaign aimed at understanding the phenomenon of black stains appeared on the passepartout close to the margins of Folio 843 of Leonardo da Vinci's Codex Atlanticus. Previous studies excluded microbiological deterioration processes. The study is based on a multi-analytical approach, including non-invasive imaging measurements of the folio, micro-imaging and synchrotron spectroscopy investigations of passepartout fragments at different magnifications and spectral ranges. Photoluminescence hyperspectral and lifetime imaging highlighted that black stains are not composed of fluorescent materials. μATR-FTIR imaging of fragments from the passepartout revealed the presence of a mixture of starch and PVAc glues localized only in the stained areas close to the margin of the folio. FE-SEM observations showed that the dark stains are localized inside cavities formed among cellulose fibers, where an accumulation of inorganic roundish particles (∅100-200 nm in diameter size), composed of Hg and S, was detected. Finally, by employing synchrotron μXRF, μXANES and HR-XRD analyses it was possible to identify these particles as metacinnabar (β-HgS). Further research is needed to assess the chemical process leading to the metacinnabar formation in the controlled conservation condition of Leonardo's Codex.
本文介绍了一项旨在了解《莱奥纳多·达·芬奇大西洋古抄本》第 843 页对开页边缘附近画框上出现黑斑现象的诊断活动。先前的研究排除了微生物恶化过程。该研究基于一种多分析方法，包括对该页进行非侵入性成像测量、对画框碎片进行微成像和同步辐射光谱研究，以不同放大倍数和光谱范围进行研究。光致发光高光谱和寿命成像表明，黑斑不是由荧光材料组成的。来自画框碎片的 μATR-FTIR 成像显示，仅在靠近对开页边缘的染色区域存在局部淀粉和 PVAc 胶水的混合物。FE-SEM 观察表明，这些深色污迹位于纤维素纤维之间形成的空腔内，其中检测到 Hg 和 S 组成的无机圆形颗粒（直径大小为∅100-200nm）的积累。最后，通过使用同步辐射 μXRF、μXANES 和 HR-XRD 分析，可以将这些颗粒鉴定为辰砂（β-HgS）。需要进一步研究以评估在莱奥纳多《抄本》的受控保存条件下导致辰砂形成的化学过程。
