Search citation statements
Paper Sections
Citation Types
Year Published
Publication Types
Relationship
Authors
Journals
The first storey of the Casa dell'Arciprete in Bergamo, Italy, built of grey limestone, is today covered with a black paint layer. A detailed investigation of the morphology and composition of this layer was necessary in order to plan conservation work in 1993. Optical and scanning electron microscopy showed that the layer is very thin and closely follows the surface of the stone. Energy-dispersive X-ray (EDX) spectra of polished cross-sections did not reveal significant differences between the elemental composition of the stone and the black layer. Fourier transform infrared (FTIR) spectra of powdered samples provided evidence of a recent conservation treatment with an acrylic resin. Reflectance micro-FTIR analyses of polished cross-sections showed weddellite as the major component of the paint layer. Hydrolysis and gas chromatography-mass spectrometry (GC-MS) analysis of black samples showed the presence of an amino acid residue that has to be ascribed to an o'riginalproteinaceous binding medium. X-ray photoelectron spectroscopy (XPS) analysis of some black surface samples characterized the pigment phase as carbon of vegetal origin. Based on this investigation, it is hypothesized that the original paint layer was composed of carbon black applied with a proteina-'ceous medium, as recommended in ancient recipes. The organic medium ,is no longer the main component of the layer but present only in trace amounts. An oxidative process may have transformed the original binder into calcium oxalate. As the underlying stone was in good condition, the painted black layer was conserved.
The first storey of the Casa dell'Arciprete in Bergamo, Italy, built of grey limestone, is today covered with a black paint layer. A detailed investigation of the morphology and composition of this layer was necessary in order to plan conservation work in 1993. Optical and scanning electron microscopy showed that the layer is very thin and closely follows the surface of the stone. Energy-dispersive X-ray (EDX) spectra of polished cross-sections did not reveal significant differences between the elemental composition of the stone and the black layer. Fourier transform infrared (FTIR) spectra of powdered samples provided evidence of a recent conservation treatment with an acrylic resin. Reflectance micro-FTIR analyses of polished cross-sections showed weddellite as the major component of the paint layer. Hydrolysis and gas chromatography-mass spectrometry (GC-MS) analysis of black samples showed the presence of an amino acid residue that has to be ascribed to an o'riginalproteinaceous binding medium. X-ray photoelectron spectroscopy (XPS) analysis of some black surface samples characterized the pigment phase as carbon of vegetal origin. Based on this investigation, it is hypothesized that the original paint layer was composed of carbon black applied with a proteina-'ceous medium, as recommended in ancient recipes. The organic medium ,is no longer the main component of the layer but present only in trace amounts. An oxidative process may have transformed the original binder into calcium oxalate. As the underlying stone was in good condition, the painted black layer was conserved.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.