FT-NIR Spectroscopy for the Non-Invasive Study of Binders and Multi-Layered Structures in Ancient Paintings: Artworks of the Lombard Renaissance as Case Studies
The work carried out was dedicated to the characterization of a series of paintings by reflection infrared spectroscopy, in particular in the near infrared (NIR) range. A substantial part of the project concerned the preparation of models (following an in-depth bibliographic research) which would allow for a thorough study of the potential of the analytical method, in order to fully understand what information it allows to obtain regarding the type of binder and preparation used by the artist, also in correlation with the thickness of the layers. The acquired knowledge was then applied to the characterization of real case studies, in some cases by associating IR spectroscopy with other techniques, such as Raman spectroscopy or SEM-EDX.
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CONCLUSIONS
The work carried out was dedicated to the characterization of a series of paintings by reflection infrared spectroscopy, in particular in the near infrared (NIR) range. To this end, a substantial part of the project concerned the preparation of models (following an in-depth bibliographic research) which would allow for a thorough study of the potential of the analytical method, in order to fully understand what information it allows to obtain regarding the type of binder and preparation used by the artist, also in correlation with the thickness of the layers. The acquired knowledge was then applied to the characterization of real case studies, in some cases by associating IR spectroscopy with other techniques, such as Raman spectroscopy or SEM-EDX.
The FT-IR analyzes of the table model have helped to deepen the topic of the analysis of binders by FT-NIR and to understand the importance of the thickness of the analyzed layers in case the spectral range of the near IR is used.
What was the goal the project set out to achieve?
In the this work, the potential of FT-NIR spectroscopy for the non-invasive characterization of binders and preparatory layers directly on the paintings was investigated.
What did I do?
Analysis project of the preparation of pictorial works through FTIR and SEM.
What was the outcome?
The only panel painting analyzed is that of Bergognone, once the painting was analyzed using FT-IR in reflection, the following conclusions were reached:
(1) The results of the analyzes indicate that in the preparation of the work on wood it is present gypsum;
(2) Oil was used as a binder, however there were signs that suggest the presence of a protein component in some places, which it could correspond to layers of tempera superimposed on the oil.
To understand the composition of the preparation of the canvas, the work of Pitocchetto was studied with the aim of analyzing its conservation problems. The analyzes made it possible to reach the following conclusions:
(1) The presence of a thin layer of CaCO₃ is also assumed in the preparation; the hypothesis is supported by the identification of calcium in the EDX analyzes of the part fibrous of the samples;
(2) FT-NIR spectra of the jacket latex and reddish ground have a signal attributable to the presence of lead palmitate , the presence of which was confirmed by EDX analysis of samples and by comparison with FT-IR spectra performed on synthesized lead palmitate in the laboratory.
(3) We can therefore hypothesize that the canvas was prepared using a thinner layer of calcium carbonate , above which to complete the preparation is was spread in oil a layer of earth presumably with the addition of white lead, according to what is reported in the recipes of the time.
What did I learn?
I learned how to manage an asset analysis project.
I also have acquired skills regarding FTIR technique and SEM technique.
FTIR · Scanning Electron Microscopy (SEM) · Analytical Chemistry · Project Coordination