The Black Hours: Material and Conservation Study, Part 1

Analysis of the middle Neolithic trichrome pottery: Characterization of the decoration using X-Ray fluorescence and Raman spectroscopy

Identification of pigments in different layers of illuminated manuscripts by X-ray fluorescence mapping and Raman spectroscopy

A novel plug-and-play setup based on polycapillary X-ray optics enables three-dimensional (3D) confocal X-ray fluorescence (XRF) and X-ray absorption spectroscopy down to 8 × 8 × 11 μm3 (17 keV) at the European Synchrotron Radiation Facility Collaborative Research Group Dutch-Belgian Beamline, BM26A. A complete description and analytical characterization is presented, together with two recently performed experimental cases. In Deep Earth diamond São Luiz-Frankfurt am Main 16, an olivine-rich inclusion was mapped with full 3D XRF elemental imaging. The preliminary tests on Iron Gall ink contained in an historical document, a letter from the court of King Philip II of Spain, reveal both the delicate nature of Iron Gall ink and the lack of Fe-Ni chemical bonding.

The study on the method of the color measurement of gold and silver foil paper is important to control color quality in the printing industry. The methods used in the experiments were to study the role of the gold tone and silver tone by studying the influence of gold tone and silver tone with different content on the chromatic value of normal color ink with different tone and different saturation. In the experiments, chromatic value of SPIN and SPEX respectively in the diffuse light conditions of color measurement could represent the chromatic value of the ink containing gold or silver ink. Then the difference of L values between SPIN and SPEX was defined as lightness difference. The ratio of the difference of saturation between SPIN and SPEX to their sum was defined as saturation ratio. Therefore, the Correlation Properties between lightness difference and saturation ratio was quantified. The result shows that with the quantity of gold and silver ink increasing, saturation ratio has linear relation with lightness difference for the same color. Similarly, with the saturation of normal ink colors increasing, saturation ratio has linear relation with lightness difference for a series of colors containing the same quantity of gold and silver ink .

The Lady with an Ermine is one of the greatest masterpieces by the Italian artist Leonardo da Vinci from around 1489-1490, depicting Cecilia Gallerani, most likely at the time when she was the mistress of Ludovico Sforza, Duke of Milan. This painting belongs to a group of four portraits of women painted by Leonardo along with the Mona Lisa, Ginevra de' Benci and La Belle Ferronnière. It was acquired by Prince Adam Jerzy Czartoryski around 1800 in Italy. In 2012, a group of conservators and scientists from the National Museum in Krakow in collaboration with experts from various institutions in Poland and abroad conducted the sixth research campaign on the painting focusing on its technological aspects. Various techniques were applied to study the materials and methods employed by Leonardo, including technical photography, X-radiography, micro X-ray fluorescence spectrometry. Physico-chemical analyses allowed to identify characteristic pigments employed by Leonardo da Vinci such as vermilion, iron-based earth pigments, lead-tin yellow, lead white, and ultramarine. The background was overpainted in black, most likely before its sale, in the 18th century. The original background most likely consists of an underlayer layer showing slight grey tone modulations obtained using iron oxide or hydroxide mineral earths. The absence of copper-based pigments in the background does not validate the hypothesis of an existing painting hidden under the black repainted zone. A dominance of lead white in brighter parts of the painting was noted, while tonal transitions were achieved using thin layers of an iron-based glaze in the sfumato technique.

The Brazilian National Library has in its collection a luxurious book of hours from the Royal Library of Portugal. For a long time, it was believed to have been made by the Italian painter Spinello Spinelli for King Fernando I (1345-1383) in 1378. This is due to the information in its colophon and the presence of a coat of arms of the Portuguese crown on the opening folio. According to recent studies, this is an example of a rare group of Flemish books of hours from ca. 1460 to English use – raising questions about the codex origin, dating, recipient, and route. To collaborate in this investigation, a material characterization study was proposed using non-invasive analyses, such as optical microscopy (OM), X-ray fluorescence (XRF), and fiber optics reflectance spectroscopy (FORS). The following pigments and materials were identified: lead white, minium, vermilion, lead-tin yellow, azurite, malachite, brazilwood lake, iron gall inks of different compositions and metals in foil or powder, namely gold and silver; moreover, the identification of lapis lazuli, Armenian bole and a different red organic lake in the colophon was decisive in corroborating the thesis of art historians, confirming the production period of the original body of the manuscript to the 15th century and that the colophon and coat of arms are later additions. Additionally, it was revealed that the coat of arms was superimposed on a previous shield.

FT-Raman, FTIR, and SERS spectra of the structurally related gallnut polyphenols tannic acid, gallic acid, pyrogallol, and syringic acid are reported in this work aiming at performing a comparative assignation of the bands and finding specific marker features that can identify these compounds in complex polyphenol mixtures. Tannic and gallic acids are the principal components in oak gallnuts, and they can be found in iron gall inks. The different functional groups existing in these molecules and their spatial distribution lead to slight changes of the vibrations. The Raman spectra are dominated by bands corresponding to the ring vibrations, but the substituents in the ring strongly affect these vibrations. In contrast, the FTIR spectra of these molecules are dominated by the peripheral oxygen-containing substituents of the aromatic ring and afford complementary information. SERS spectroscopy can be used to analyze trace amounts of these compounds, but the spectra of these polyphenols show strong changes in comparison with the Raman spectra, indicating a strong interaction with the metal. The most significant modification observed in the SERS spectra of these compounds is the weakening of the benzene 8a ring vibration and the subsequent intensification of the 19a mode of the benzene ring. This mode is also more intense in the FTIR spectra, and its intensification in the SERS spectra could be related to a drastic change in the molecular polarizability associated with the interaction of the polyphenol with the metal in Ag NPs.

In this study, the effects of calcination on the structural properties and surface morphology of black volcanic ash were investigated. The chemical composition, texture properties, and thermal behavior of raw black volcanic ash were studied using x-ray fluorescence spectrometry, micromeritics surface area, porosity analyzer, and thermogravimetric and differential scanning calorimetry analysis, respectively. According to the thermogravimetric results, the powder of raw volcanic ash was calcined at 800, 1000, and 1100 °C. X-ray diffraction (XRD), Raman spectroscopy, and electron microscopy were employed to study the crystalline phase, mineralogical composition, and morphology of the calcinated volcanic ash. Based on the characterization of the XRD and Raman spectra, we observed that phase transformation started at 800 °C along with a change in color of volcanic ash from black to poor red. Moreover, the degree of crystallinity and peak intensity increased as the calcination temperature increased, without a significant change in the surface morphology. These findings can help in understanding the surface and bulk characteristics of black volcanic ash at high temperatures and serve to enhance their technological and economical applications.

Chicken cartilage was used for the first time as a raw material for the microwave-assisted synthesis of biochar and activated carbon. Various microwave absorbers, i.e., commercial active carbon, scrap tyres, silicon carbide, and chicken bone-derived biochar, as well as various microwave powers, were tested for their effect on the rate of pyrolysis and the type of products formed. Biochars synthesised under 400 W in the presence of scrap tyres and chicken bone-derived biochar were activated with KOH and K2CO3 with detergent to produce activated carbon with a highly developed porous structure that would be able to effectively adsorb xylene vapours. All carbons were thoroughly characterised (infrared spectroscopy, X-ray fluorescence spectrometry, nitrogen adsorption/desorption, Raman spectroscopy, proximate and ultimate analysis) and tested as xylene sorbents in dynamic systems. It was found that the activation causes an increase of up to 1042 m2·g-1 in the specific surface area, which ensures the sorption capacity of xylene about 300 mg·g-1. Studies of the composition of biogas emitted during pyrolysis revealed that particularly valuable gaseous products are formed when pyrolysis is carried out in the presence of silicon carbide as a microwave absorber.

A new approach to the conservation of paper manuscripts is proposed that leads to both deacidification and strengthening of paper. The study was carried out by using polyamidoamines (PAAOHs) functionalized with alcoholic groups, in their native form (PAAb) or neutralized with boric acid (PAAn). They were applied on model paper samples containing iron-gall ink spots through agar rigid gel or by brushing. Preliminary evaluation of the effects of polymer concentration, methods, and duration of application have been tested on model ink-free paper samples. The improvements induced by PAAOHs on paper samples was revealed by surface pH (evaluated in ink-free areas, inside ink spots and on the edges between them) and by measurements of alkaline reserve according to TAPPI T 553 pm-92. The results showed the different behaviour of ink-free and inked regions due to high acidity of iron gall ink. In fact, although a treatment with solutions having low concentration (i.e. 0.1 and 0.15 M) is sufficient for preserving ink-free paper samples from ageing, higher concentration of polymer (0.3 M) or extra brushing application are needed in order to get a complete deacidification of the ink spots. As a side-effect of deacidification treatments, PAAOHs promoted a significant reduction of thermo-hygrometric ageing effects and water smearing at the edge of iron-gall ink spots, as suggested by Raman spectroscopy and mechanical analyses.

ABSTRACTA review has been conducted on the application of the spectroscopic techniques to the comparative study and identification of different textile fibers. Microspectrophotometry in the ultraviolet-visible range and Raman spectroscopy are the main techniques investigated with this aim in the forensic field. UV-Vis MSP is the first recommended technique, which is principally used to study the color of the fibers. A more complete approximation focused on determining the specific color of the fibers providing adding Raman spectroscopy to the analytical scheme. Sometimes, it also provided information about the polymeric nature of the fibers. Regarding FTIR spectroscopy, it is the recommended tool to determine the fiber nature. Raman and FTIR spectroscopy are complementary techniques and a frequent recommendation is a combination of both techniques, in order to get a comprehensive analysis of textile fibers. On the other hand, new and more informative analytical techniques are emerging to the analysis of textile fibers as traces related with criminal contacts, such as infrared chemical imaging spectroscopy and X-ray fluorescence spectroscopy.

The effect of chemical composition on the Raman spectra of a series of natural calcalkaline silicate glasses has been quantified by performing electron microprobe analyses and obtaining Raman spectra on glassy filaments (~450 µm) derived from a magma mingling experiment. The results provide a robust compositionally‐dependent database for the Raman spectra of natural silicate glasses along the calcalkaline series. An empirical model based on both the acquired Raman spectra and an ideal mixing equation between calcalkaline basaltic and rhyolitic end‐members is constructed enabling the estimation of the chemical composition and degree of polymerization of silicate glasses using Raman spectra. The model is relatively insensitive to acquisition conditions and has been validated using the MPI‐DING geochemical standard glasses1 as well as further samples. The methods and model developed here offer several advantages compared with other analytical and spectroscopic methods such as infrared spectroscopy, X‐ray fluorescence spectroscopy, electron and ion microprobe analyses, inasmuch as Raman spectroscopy can be performed with a high spatial resolution (1 µm2) without the need for any sample preparation as a nondestructive technique. This study represents an advance in efforts to provide the first database of Raman spectra for natural silicate glasses and yields a new approach for the treatment of Raman spectra, which allows us to extract approximate information about the chemical composition of natural silicate glasses using Raman spectroscopy. We anticipate its application in handheld in situ terrestrial field studies of silicate glasses under extreme conditions (e.g. extraterrestrial and submarine environments). © 2015 The Authors Journal of Raman Spectroscopy Published by John Wiley & Sons Ltd

Chemical and spectroscopic study of nephrite artifacts from Transbaikalia, Russia: Geological sources and possible transportation routes

Graphene-coated alumina nano/microfibers as filler for composites

Carbon fiber from natural biopolymer Bombyx mori silk fibroin with iodine treatment