New Insights to Characterize Paint Varnishes and to Study Water in Paintings by Nuclear Magnetic Resonance Spectroscopy (NMR)

Abstract

Paintings are complex multi-layered systems made of organic and inorganic materials. Several factors can affect the degradation of paintings, such as environmental conditions, past restoration works and, finally, the type of painting technique and the art materials used over the centuries. The chemical–physical characterization of paintings is a constant challenge that requires research into and the development of novel analytical methodologies and processes. In recent years, solvents and water-related issues in paintings are attracting more attention, and several studies have been focused on analyzing the interaction between water molecules and the constitutive materials. In this study, recent applications applying different NMR methodologies were shown, highlighting the weakness and the strength of the techniques in analyzing paintings. In particular, the study of water and its diffusive interactions within wall and oil paintings was performed to prove how the portable NMR can be used directly in museums for planning restoration work and to monitor the degradation processes. Furthermore, some preliminary results on the analysis of varnishes and binders, such us linseed oil, shellac, sandarac and colophony resins, were obtained by 1H HR-MAS NMR spectroscopy, highlighting the weakness and strengths of this technique in the field of conservation science.

Recent advances and applications to cultural heritage using ATR-FTIR spectroscopy and ATR-FTIR spectroscopic imaging

“…64 More detailed information can be acquired by examining the stratigraphy of paintings. Non-invasive approaches such as Optical Coherence Tomography (OCT), 65 Nuclear Magnetic Resonance (NMR), 66 Terahertz imaging, 67 confocal XRF 68,69 and micro-Spatially Offset Raman Spectroscopy (micro-SORS) 69 can be performed to investigate and characterise the layer successions, but they are not able to provide the two-dimensional distribution of compositional information of the materials. ATR-FTIR spectroscopy can be combined with multivariate techniques to analyse spatial and compositional information of the stratigraphy of a painting.…”

Numerical Computation and Analysis of Electromagnetic Field in Magnetic Suspension and Balance System

“…Its current is large and its fluctuation range is small, so it can be regarded as a static magnetic field. The working frequency of NMR is higher than 1 MHz [16], the current is small, the fluctuation range is large, it is a mainly dynamic magnetic field.…”

Discovering Giuseppe Capogrossi: Study of the Painting Materials in Three Works of Art Stored at Galleria Nazionale (Rome)

“…The project, whose complete results will be published elsewhere in an extended form including the determination of the palette and pigments [37], involved the collaboration of several Italian institutions. It included an initial phase based on non-invasive investigations (multispectral imaging, X-ray fluorescence, reflection FT-IR spectroscopy and unilateral NMR-MOUSE [38]), followed by micro-destructive laboratory analyses (Py-GC-MS, GC/MS and HPLC-ESI-Q-ToF, SEM-EDS, optical microscopy) on the samples. Here, only the results obtained by reflection FT-IR spectroscopy, chromatography and mass spectrometry are presented, focused on the study of the organic binders in the paint and in the preparation layers.…”