Heritage science involves research on cultural heritage, including analysis, provenance, conservation, and statistical methods, and chemistry has a key role to play in this field. This virtual issue highlights papers that will be included in an upcoming special issue of Angewandte Chemie featuring heritage science, as well as other recent contributions. Do you want to know about the cannonballs on the Mary Rose battleship or the secret of Stradivari's varnishes? How can we classify degrading plastic objects simply by smelling them? The answers are all found in the papers below.
Heritage Science: A Future‐Oriented Cross‐Disciplinary Field
“… Heritage science is the study of interpretation and management of the material evidence of the humankind. It enables both society and individuals to exercise their right to cultural heritage and contributes to our understanding of who we are and our sense of place. Heritage science demonstrates its relevance to, as well as its deep roots in chemistry, and in other physical and engineering sciences …” Read more in the Guest Editorial by Matija Strlič.
Photochemistry of Artists’ Dyes and Pigments: Towards Better Understanding and Prevention of Colour Change in Works of Art
Dr. Costanza Miliani, Dr. Letizia Monico, Prof. Maria J. Melo, Dr. Simona Fantacci, Dr. Eva M. Angelin, Prof. Aldo Romani, Prof. Koen Janssens Angewandte Chemie International Edition First Published: 26 April 2018
What light does to colours: Light may provoke irreversible colour changes of artworks due to chemical transformations of their constitutive materials. Chemistry, by exploiting multi‐scale analytical investigations, computational modelling and physical and chemical studies, contributes to improve our prediction of artwork appearance before degradation and to establish effective preventive conservation strategies.
Recent Advances in Analytical Pyrolysis to Investigate Organic Materials in Heritage Science
Analytical pyrolysis is experiencing previously unexplored potential, thanks to recent instrumental developments. Recent advances in the heritage field enable the investigation of several organic materials in artistic and historical objects that are macromolecular in nature, or which undergo polymerization upon curing and ageing, by strategies based on analytical pyrolysis coupled with mass spectrometry.
Cultural Heritage Studies with Mobile NMR
Nondestructive NMR has unique opportunities in cultural heritage science as it reports physical properties that no other method has access to. Direct measurements of the water content, self‐diffusion, and relaxation times reveal layered structures under the surface of intact objects without harmful interaction. Easel and wall paintings, wooden instruments, and even biological samples and human remains are being investigated.
Microemulsions, Micelles, and Functional Gels: How Colloids and Soft Matter Preserve Works of Art
Colloids and soft matter provide systems that enable the selective removal of soil and aged coatings from works of art. Microemulsions and micelles favour the de‐wetting and detachment of polymer films from artistic surfaces; the detached films can be easily removed, recovering the artefact's aesthetic appearance. Gels can confine the cleaning fluids and release them gradually, avoiding overcleaning and leaching of original components.
Paleo‐inspired Systems: Durability, Sustainability, and Remarkable Properties
Paleo‐inspiration, the process of mimicking properties of specific interest (mechanical, optical, structural) observed in ancient and historical systems, is proposed for innovative chemical conception. The inspiration gained from an advanced study of ancient materials that were often synthesized in soft chemical ways, using low energy resources, and sometimes rudimentary manufacturing equipment is discussed.
Modeling the Evolution of Crosslinked and Extractable Material in an Oil‐Based Paint Model System
Kinetic analysis: A detailed kinetic model of the oxidation of an oil paint model system provided deeper insight into the formation of crosslinked and volatile material in oil paint layers which contribute to the long‐term stability of artworks. The model successfully predicts several experimental metrics of oxidative curing such as the formation of aldehydes.
Crowdsourcing as an Analytical Method: Metrology of Smartphone Measurements in Heritage Science
The wisdom of the crowd: The precision, repeatability, and accuracy of crowdsourced colour and area measurements are estimated. The results indicate that smartphone measurements provided by non‐scientists can be used to measure changes in colour, but that the performance is strongly dependent on the measured colour coordinate.
Spectral Imaging and Archival Data in Analysing Madonna of the Rabbit Paintings by Manet and Titian
Dr. Jana Striova, Dr. Chiara Ruberto, Dr. Marco Barucci, Dr. Jan Blažek, Diane Kunzelman, Alice Dal Fovo, Enrico Pampaloni, Dr. Raffaella Fontana Angewandte Chemie International Edition First Published: 17 April 2018
Your greatest shade of blue: Mapping blue pigments in Manet's painting Madonna of the rabbit and of Titian's homonymous painting by spectral correlation of Vis‐NIR multispectral data complemented with XRF mapping. The comparative study demonstrates that not only the palettes used by the two artists were different but also that the colours of the two paintings differ. Manet used Prussian and Cobalt blues whereas Titian employed azurite and natural ultramarine blue.
Pigment and Binder Concentrations in Modern Paint Samples Determined by IR and Raman Spectroscopy
Dr. Rita Wiesinger, M. Sc. Laura Pagnin, Dr. Marta Anghelone, Prof. Dr. Ligia M. Moretto, Prof. Dr. Emilio F. Orsega, Prof. Dr. Manfred Schreiner Angewandte Chemie International Edition First Published: 27 April 2018
The potential of IR and Raman spectroscopy for quantifying the relative concentrations of pigments and binders in modern paint samples has been explored. The investigated materials were acrylic and alkyd polymeric binders, namely, Plextol D498 and Alkyd Medium 4, in a mixture with three different inorganic pigments: artificial ultramarine blue, hydrated chromium oxide green and cadmium yellow.
Using Optical Coherence Tomography to Reveal the Hidden History of The Landsdowne Virgin of the Yarnwinder by Leonardo da Vinci and Studio
Prof. Dr. Piotr Targowski, Dr. Magdalena Iwanicka, Dr. Marcin Sylwestrzak, Dr. Cecilia Frosinini, Dr. Jana Striova, Dr. Raffaella Fontana Angewandte Chemie International Edition First Published: 07 March 2018
Optical coherence tomography (OCT) provides insight into the subsurface structure of paintings from Leonardo da Vinci's studio. Details were revealed that were not accessible by routine Vis–NIR–UV‐excited fluorescence imaging. Specific details of former restorations, namely overpaintings and traces of two transfers, are disclosed.
Chemical Mapping by Macroscopic X‐ray Powder Diffraction (MA‐XRPD) of Van Gogh's Sunflowers: Identification of Areas with Higher Degradation Risk
Frederik Vanmeert, Prof. Dr. Ella Hendriks, Dr. Geert Van der Snickt, Dr. Letizia Monico, Prof. Dr. Joris Dik, Prof. Dr. Koen Janssens Angewandte Chemie International Edition First Published: 02 March 2018
Sunflowers: In addition to the light‐fast chrome yellow subtype PbCrO4 (crocoite), light‐sensitive monoclinic PbCr1−xSxO4 (x≈0.5, LS‐CY) was found throughout several areas of Van Gogh's Sunflowers, thus identifying areas of the painting that are at risk of darkening. In addition, information on the orientation of LS‐CY pigment crystallites in Van Gogh's brush strokes were revealed.
A Synchrotron‐Based Study of the Mary Rose Iron Cannonballs
After excavation, iron artefacts are at risk of loss or damage from corrosion, which may be accelerated by the presence of Cl−. This has led to the development of conservation treatments to remove chlorine. Thirty years of conservation applied to cannonballs from the Mary Rose shipwreck are reviewed, using synchrotron‐based techniques to assess the impact of conservation choices on iron corrosion.
Egyptian Grave Goods of Kha and Merit Studied by Neutron and Gamma Techniques
Dr. Giulia Festa, Dr. Triestino Minniti, Dr. Laura Arcidiacono, Dr. Matilde Borla, Dr. Daniela Di Martino, Dr. Federica Facchetti, Dr. Enrico Ferraris, Dr. Valentina Turina, Dr. Winfried Kockelmann, Dr. Joe Kelleher, Prof. Roberto Senesi, Dr. Christian Greco, Prof. Carla Andreani Angewandte Chemie International Edition First Published: 05 March 2018
This side of the grave: Artifacts from the Egyptian grave goods of Kha and Merit preserved at the Museo Egizio in Turin were studied through a combination of non‐destructive and non‐invasive neutron and gamma techniques (neutron imaging, neutron diffraction, and prompt gamma activation analysis). The results provide unprecedented morphological reconstructions of the inner parts of the two alabaster and metallic vases and their isotopic and phase composition.
Layered Nano‐TiO2 Based Treatments for the Maintenance of Natural Stones in Historical Architecture
Stones gathering no moss: Layered treatments of natural stones based on dispersions of experimental nano‐TiO2 and commercial TEOS were set‐up to avoid the penetration of NPs into the crystalline porous substrates and to improve their adhesion to the stone. The combined SiO2‐nano‐TiO2 treatments demonstrate enhanced photocatalytic and self‐cleaning properties compared to NPs dispersions.
Time‐Dependent ATR‐FTIR Spectroscopic Studies on Fatty Acid Diffusion and the Formation of Metal Soaps in Oil Paint Model Systems
The formation of metal soaps (metal complexes of saturated fatty acids) is a serious problem affecting the appearance and structural integrity of many oil paintings. Tailored model systems for aged oil paint and time‐dependent ATR‐FTIR spectroscopy were used to study the diffusion of palmitic acid and subsequent metal soap crystallization.
Rediscovering Ducos du Hauron's Color Photography through a Review of His Three‐Color Printing Processes and Synchrotron Microanalysis of His Prints
Dr. Marine Cotte, Tiphaine Fabris, Juliette Langlois, Prof. Ludovic Bellot‐Gurlet, Françoise Ploye, Natalie Coural, Dr. Clotilde Boust, Jean‐Paul Gandolfo, Thomas Galifot, Dr. Jean Susini Angewandte Chemie International Edition First Published: 20 March 2018
From obscurity to light: A review of 19th century processes published by the Ducos du Hauron brothers on trichrome printing in combination with synchrotron‐based microanalysis of fragments from three early artifacts of Louis Ducos du Hauron highlights complex multistep processes and multilayered compositions, with clear historical evolutions and chemical signatures.
Glass and Alchemy in Early Modern Europe: An Analytical Study of Glassware from the Oberstockstall Laboratory in Austria
What sort of operations did alchemists carry out in their laboratories? What tools did they use? Can answering similar questions help us better understand the development of science and technology in the Renaissance? It is shown that the information gained through archaeometric analysis of artefacts from laboratories can be a powerful tool in exploring how alchemy was practiced in early modern Europe.
Classifying Degraded Modern Polymeric Museum Artefacts by Their Smell
Sniffing out decay: Detection of volatile organic compounds (VOCs) has been studied widely in disease diagnosis and it has many advantages that make it relevant to understanding the condition of cultural heritage artefacts. The feasibility of using VOC detection is explored to assess degradation in modern heritage objects made of plastic, including artefacts from the collections at Tate.
Polymer Film Dewetting by Water/Surfactant/Good‐Solvent Mixtures: A Mechanistic Insight and Its Implications for the Conservation of Cultural Heritage
Dr. Michele Baglioni, Dr. Costanza Montis, Dr. David Chelazzi, Prof. Rodorico Giorgi, Prof. Debora Berti, Prof. Piero Baglioni Angewandte Chemie International Edition First Published: 07 December 2017
Aqueous nanostructured fluids (NSFs) are established tools with unique efficacy in the removal of hydrophobic polymer coatings from works of art. Here, we investigated the interaction of p(EMA/MA) films and NSFs to disentangle the mechanism of NSFs‐induced polymer film dewetting. Experimental data on simplified polymer‐coated coverglasses highlighted the specific role of each NSF component in kinetically promoting polymer dewetting. FTIR imaging on polymer‐coated mortar tiles confirmed the reliability of the theoretical description of NSFs‐polymer interaction in real case studies.
Standoff Mid‐Infrared Emissive Imaging Spectroscopy for Identification and Mapping of Materials in Polychrome Objects
Mid‐infrared imaging spectroscopy was used to map chemical functional groups by measuring reflectance or emissivity spectra. An indoor‐collection configuration for obtaining mid‐IR emissivity image cubes of paintings is demonstrated. Using this method and a high‐throughput, low‐noise, line‐scanning imaging spectrometer, pigments and paint binders were identified and mapped.
Evidence for Degradation of the Chrome Yellows in Van Gogh’s Sunflowers: A Study Using Noninvasive In Situ Methods and Synchrotron‐Radiation‐Based X‐ray Techniques
Dr. Letizia Monico, Prof. Koen Janssens, Dr. Ella Hendriks, Frederik Vanmeert, Dr. Geert Van der Snickt, Dr. Marine Cotte, Dr. Gerald Falkenberg, Prof. Brunetto Giovanni Brunetti, Dr. Costanza Miliani Angewandte Chemie International Edition First Published: 20 October 2015
Why is the yellow darkening? Firm evidence that chrome yellow pigments darken through the CrVI→CrIII reduction is provided by the use of complementary analytical techniques. Different types of chrome yellow, that is, the lightfast PbCrO4 and the light‐sensitive sulfur‐rich PbCr1−xSxO4 (x≈0.5), are shown to be present, and spots of the painting with the highest risk of color change have been identified.
Plumbonacrite Identified by X‐ray Powder Diffraction Tomography as a Missing Link during Degradation of Red Lead in a Van Gogh Painting
Unravelling minium degradation: The very rare lead carbonate mineral plumbonacrite was identified in a Van Gogh painting using combined microscopic X‐ray fluorescence and X‐ray powder diffraction mapping and tomography methods. Thanks to the high spatial resolution and specificity of this technique an additional step in the photochemical degradation pathway of red lead (minium) is demonstrated.
Egg White Varnishes on Ancient Paintings: A Molecular Connection to Amyloid Proteins
Egg white coatings: Why was egg white used and what were its unique properties as a varnish for paintings? These questions have puzzled the art community for hundreds of years. A molecular basis is given for the beneficial properties of egg white varnishes on paintings (see AFM amplitude image of egg white coated on a PTFE membrane) using ATR‐FTIR spectra and one of its protective properties by oxygen transport.
Nanoscale Investigation of the Degradation Mechanism of a Historical Chrome Yellow Paint by Quantitative Electron Energy Loss spectroscopy Mapping of Chromium Species
Getting the picture: The investigation of 100 year old chrome yellow paint by transmission electron microscopy and spectroscopy has led to the identification of four types of core–shell particles. This nanoscale investigation has allowed a mechanism to be proposed for the darkening of some bright yellow colors in Van Gogh's paintings (e.g. in Falling leaves (Les Alyscamps), 1888).
Noninvasive Analysis of Paintings by Mid‐infrared Hyperspectral Imaging
Dr. Francesca Rosi, Dr. Costanza Miliani, René Braun, Dr. Roland Harig, Diego Sali, Prof. Brunetto G. Brunetti, Prof. Antonio Sgamellotti Angewandte Chemie International Edition First Published: 15 April 2013
Cultural detective work: Remote hyperspectral imaging in the mid‐infrared region enables the identification and localization of the painting materials used by artists (see brightness temperature difference image overlayed with the corresponding portion of the painting Sestante 10 by Alberto Burri and IR reflection spectra for this area). The resulting molecular images are thus of great value for art conservation.
Revealing the sfumato Technique of Leonardo da Vinci by X‐Ray Fluorescence Spectroscopy
Not just a pretty face: Non‐invasive X‐ray fluorescence spectroscopy was used to reveal the sfumato paint layer stacking method that was used by Leonardo da Vinci to paint the faces in seven of his paintings. A strong diversity in his technique could clearly be seen with this method.
The Nature of the Extraordinary Finish of Stradivari’s Instruments
Jean‐Philippe Echard, Loïc Bertrand Dr., Alex von Bohlen Dr., Anne‐Solenn Le Hô Dr., Céline Paris Dr., Ludovic Bellot‐Gurlet Dr., Balthazar Soulier, Agnès Lattuati‐Derieux Dr., Sylvie Thao, Laurianne Robinet Dr., Bertrand Lavédrine Prof., Stéphane Vaiedelich Angewandte Chemie International Edition First Published: 22 December 2009
What is Stradivari's “secret”? The composition of the mythical varnish that coats Stradivari's violins has raised controversial assumptions for the past two centuries. By using a complementary array of analytical tools, the chemical microstratigraphy of these varnishes has been established. The results provide information on the materials and techniques that were used by the Master, with a detailed characterization of the varnish.