Binding Media Research Articles

Characterization of grounds, pigments, binding media, and varnish coating of the Angel Michael' icon, 18th century, Egypt

Samples from canvas, grounds, pigments, and varnish coating from the icon of Angel Michael came back to the 18th century from the church of Samanod, Gharbeia Governorate, Egypt, were investigated using multispectral signals of SEM-EDX, FT-IR, and Mass spectrometry. The SEM data from the canvas indicated that it is of linen. EDX of the grounds indicated that they are of gypsum with natural impurities of halite, quartz, and clay minerals. FT-IR spectra of the grounds indicated that the binding medium was of animal glue where gypsum was mixed with animal glue. The SEM-EDX pattern of the orange pigment showed the presence of lead, minium (Pb3O4) is the most probable, the blue color was Egyptian blue, whereas tetrahyrate [(Cu, Fe, Zn, Ag)12Sb4S18)] may be used as a source of copper and crushed limestone was used as a source of flux. The gold color is composed red lead mixed with titanium oxide. The icon paintings were coated with a resinous layer of dammar, which had darkened into a brown color by photoxidation.

Searching for blood in Chinese lacquerware: zhū xiě huī 豬 血 灰

The study gives an overview of the tests and analyses undertaken in the past 20 years to establish the presence of blood in the foundation layers of Chinese lacquer artefacts and also shows the development of analytical methods over that period. When undertaking the conservation of lacquer objects it is crucial to know the type of binding medium as this influences the selection of any consolidants that may be required in the treatment. Microchemical tests to identify blood using benzidine and luminol, various chromatographic and mass spectrometric techniques and DNA analyses were assessed on selected Chinese lacquer objects, and the results gained are summarized.

A review of ancient Egyptian pigments and cosmetics

The pigments used by the ancient Egyptians constitute the most diverse pigment palette of the ancient world. This review discusses the pigments and binders which were used, arranged principally in terms of the colours themselves, namely, the white, green, grey, black, brown, blue, red, orange, and yellow pigments. The chemical identity of these pigments is discussed with some details regarding the artefacts or time periods from which the pigment concerned has been identified. Combinations of pigments were used for creating some colours, especially: greens, pinks, blues, yellows, and a variety of pale hues by mixing primary colours with a white addition, such as calcite. The identification of ancient Egyptian pigments is often aggravated by chemical interactions between pigment and binder media, or between the pigment and environmental pollutants, or both. The nature of the binders and varnishes used in ancient Egypt is briefly discussed. The identification of green pigments from ancient Egypt is often difficult, and some of the recent research concerning the topic is reviewed. In addition to including relevant details from older literature, this review provides a synopsis of recent studies which have appeared since the last major review carried out by Lee and Quirke in 2000.

Infrared spectroscopic and chemometric approach for identifying binding medium in Sukias mansion’s wall paintings

This paper addresses the application of infrared spectroscopy in combination with chemometrics to identify wall painting’s binding medium while employing pattern recognition techniques to process FTIR data-set of complex samples. In this regard, based on the historical documents and previous researches, firstly 56 standard samples were prepared to represent strata of Persian wall paintings in the Safavid period in addition to real historic samples from the case study; Sukias mansion. Then, each sample was analysed by the means of FTIR and chemometrics. Finally, SIMCA was applied to the whole region of studied IR spectra which predicted egg yolk as the binding medium of Sukias mansion samples.

Direct inlet mass spectrometry for a rapid characterization of indigo in lipidic and proteinaceous matrices

Direct inlet mass spectrometry (DI-MS) was examined for its suitability to quickly identify indigo in mixtures with lipidic and proteinaceous binders, such as those characteristic of paintings and polychromy. The technique was tested on naturally aged reference mixtures of indigo with linseed oil, rabbit skin glue, and whole egg. DI-MS with electron ionization at 70eV served as an efficient tool for screening indigo in complex matrices and provided, at the same time, a mass spectral fingerprint of the organic binder in just a few minutes. The technique was applied to the identification of indigo in a blue sample from a mural painting dated from the 18th century and housed in an Andean church in Bolivia. At the same time, the acquired data revealed for the first time the use of an egg tempera binding medium in an Andean mural painting.

Investigation of painted stucco in historic buildings of Delta, Egypt

Samples removed from stucco ornaments of two mosques (seventeenth century) in El-Mahalla El-Kubra, Delta, Egypt, are investigated using optical microscopy, micro-Raman and micro-FTIR spectroscopy and X-ray diffraction (XRD). Samples are studied as removed from the ornaments and after treatment with trichloromethane, which was used to extract the organic content. Moreover, the stratigraphies of the ornaments are investigated through a sample’s cross-section analysis revealing a bulk stucco layer, a colouring layer (either red or black) and overpainted layers of later interventions. Red and black colouring layers are composed mainly of fired brick enriched with hematite and carbon black, respectively. Shellac, found in high quantities, is the binding medium used in the colouring layers where small amounts of tree resins are detected as well. Bulk stucco is composed of gypsum and calcite. Metal soaps, oil and tree resins are also detected in the stucco layers. Other identifications are described in the report which, to the best of our knowledge, is the first effort to identify the materials contained in the “Delta style” stucco used in Ottoman buildings in Egypt.

Scientific studies for the restoration of a wood painting of the Galleria Interdisciplinare Regionale della Sicilia—Palazzo Mirto di Palermo

The Ritratto muliebre, referring to Venus, is a panel painting, oil on wood, attributed to unknown artist and probably dated to the second half of 16th century, today conserved in the Galleria Interdisciplinare Regionale della Sicilia—Palazzo Mirto of Palermo.The aim of this research was to assess the techniques used to decorate the wooden painting and to verify the state of conservation of the artwork's materials but also to identify the previous treatments. This study was the essential condition to plane and perform the correct restoration.For this reason, an integrated analytical approach based on the use of non-invasive and micro-invasive techniques was used, with the aim to obtain a characterization of the wooden panel, to elucidate the painting technique, including the stratigraphic sequence of the pigments and the organic binders, the state of preservation, the possible decay processes, and the possible additions made during previous restorations.In addition to the imaging diagnostics techniques and the microchemical spot tests, micro-fragments of the painted material, original or not, were analyzed by several analytical techniques: optical microscopy, scanning electron microscopy (SEM-EDAX), FT-IR spectroscopy, and X-ray photoelectron spectroscopy (XPS).The results of all analyses revealed that the portrait is a small panel painting made by an unknown painter in the second half of 16th century, with a traditional painting technique: a single wooden panel, two preparatory layers (“ammannitura”), a sort of priming (“imprimitura”), an underdrawing, a paint layer composed of oil as binding medium and pigments common in 16th century.

Micro FTIR imaging for the investigation of deteriorated organic binders in wall painting stratigraphies of different techniques and periods

This work deals with the detection and imaging of metal oxalates/carboxylates in the paint layers of ancient wall paintings and with the investigation of their possible association with the ageing of organic substances used as binding media in the original painting. This assumption is investigated employing Fourier transform infrared (FTIR) imaging on several case studies; starting with a thin section of the paint stratigraphy extracted from extensively deteriorated post-Byzantine murals, painted with an oil binder. Metal carboxylates and oxalates show their maximum concentration at the interface of free fatty acids and pigment particles, indicating a possible origin of their formation. Then, the methodology was applied in paint thin sections, originating from Prehistoric, Roman and Hellenistic wall paintings. In these case studies, metal oxalates detected within the paint layers were explored regarding their relation to the use of an organic binder in the wall paintings. The chemical images of calcium oxalates in the paint layers of the Prehistoric wall paintings was a trigger for further laborious investigation on numerous samples, which resulted in revealing the spectrum of an aged proteinaceous binding medium. Thereafter, the distribution of metal oxalates within the paint layers of the samples from the Roman and Hellenistic wall paintings, unaffected by any later intervention, was assumed as an indirect indication of the use of an original organic binder.

ToF-SIMS characterization of proteinaceous binders in the wall painting “Madonna and Child enthroned with Saints” by Ambrogio Lorenzetti in the St. Augustine Church (Siena, Italy)

In this paper, we report the results of investigations, by means of ToF-SIMS and HPLC, of samples taken from the wall painting “Madonna and Child Enthroned with Saints” (1335–1338) by Ambrogio Lorenzetti. The aim of this study was to test the capability of ToF-SIMS to identify the nature of the protein-based binders used in the wall painting. The peaks characteristic of egg components were observed in the ToF-SIMS mass spectra of the a secco-applied layers. On the contrary, the ToF-SIMS spectra of the a fresco-applied layers did not show the markers of egg. The PCA results of the protein peaks are consistent with the presence of a rabbit glue–egg mixture. The PCA of protein peaks in the ToF-SIMS spectra was carried out for artificially aged and non-aged reference samples of rabbit glue, casein, egg and their mixtures in order to estimate the effect of ageing on protein-based binding media. Both ToF-SIMS and HPLC data showed that animal glue was present in the a secco- and a fresco-applied layers. On the basis of these results, we can conclude that animal glue was not used as binding medium but was probably applied to the wall painting in prior restorations.

ToF-SIMS imaging of molecular-level alteration mechanisms in Le Bonheur de vivre by Henri Matisse.

Time-of-flight secondary ion mass spectrometry (ToF-SIMS) has recently been shown to be a valuable tool for cultural heritage studies, especially when used in conjunction with established analytical techniques in the field. The ability of ToF-SIMS to simultaneously image inorganic and organic species within a paint cross section at micrometer-level spatial resolution makes it a uniquely qualified analytical technique to aid in further understanding the processes of pigment and binder alteration, as well as pigment-binder interactions. In this study, ToF-SIMS was used to detect and image both molecular and elemental species related to CdS pigment and binding medium alteration on the painting Le Bonheur de vivre (1905-1906, The Barnes Foundation) by Henri Matisse. Three categories of inorganic and organic components were found throughout Le Bonheur de vivre and co-localized in cross-sectional samples using high spatial resolution ToF-SIMS analysis: (1) species relating to the preparation and photo-induced oxidation of CdS yellow pigments (2) varying amounts of long-chain fatty acids present in both the paint and primary ground layer and (3) specific amino acid fragments, possibly relating to the painting's complex restoration history. ToF-SIMS's ability to discern both organic and inorganic species via cross-sectional imaging was used to compare samples collected from Le Bonheur de vivre to artificially aged reference paints in an effort to gather mechanistic information relating to alteration processes that have been previously explored using μXANES, SR-μXRF, SEM-EDX, and SR-FTIR. The relatively high sensitivity offered by ToF-SIMS imaging coupled to the high spatial resolution allowed for the positive identification of degradation products (such as cadmium oxalate) in specific paint regions that have before been unobserved. The imaging of organic materials has provided an insight into the extent of destruction of the original binding medium, as well as identifying unexpected organic materials in specific paint layers.

Surface Characterization of Biomimetic Hydroxyapatite-Silver Functionalized on Polydopamine Film

Hydroxyapatite (HA) is a well known bioactive material in the application of coated orthopaedic and dental implants. Recently, biomimetic technique has been explored to deposit a stable carbonated HA on a metal surface, mimicking the properties of natural bone. The aim of this study is to surface characterize the biomimetic hydroxyapatite (HA) and metallized silver (Ag) functionalized on a polydopamine film grafted titanium alloy (Ti6Al4V). The Ti6Al4V disks were grafted with the polydopamine film to provide catechol/quinone groups for chemical binding process. The grafted surfaces were metallized with Ag in silver nitrate solution. The metallized surfaces were then grafted with the second layer of polydopamine film and further biomineralized with HA in 1.5 simulated body fluid (SBF) solution for 3 and 7 days. The chemical compositions and chemical functionalities of those functionalized surfaces were characterized by XPS, FTIR and EDS. The morphologies of the surfaces were viewed under SEM. Finally, the wettability properties of the surfaces were investigated by water contact angle analysis. The XPS results showed that the polydopamine films were grafted on the Ti6Al4V surfaces. The polydopamine films became the chemical binding medium for functionalization of Ag and HA as the existence of both elements were clarified in XPS and EDS data. The appearance of HA functional groups (phosphate groups) were only noticed on FTIR spectrum when the biomimetic process was performed at 7 days. The formation of biomimetic HA has produced a hydrophilic surface with an appearance of hemispherical lath-like HA structure which is crucial for osseointegration and bone growth stability.

Hydrofluoric acid pre-treatment of matte artists’ paints for binding medium analysis by Fourier transform infrared microspectroscopy

A rapid and safe method has been developed for preparing matte artists’ paint samples for binding medium analysis by Fourier transform infrared (FTIR) microspectroscopy. Hydrofluoric acid (HF) transforms many inorganic components of matte paints that commonly interfere with medium analysis, viz. carbonate and silicate fillers and pigments, into chemical species whose infrared absorptions are shifted outside the spectral area of interest. This method provides a route for removing these interferences without relying on lengthy and sometimes unsuccessful solvent extraction of the binding medium. Microsamples of common binders, pigments, and inorganic fillers were reacted with solution or gas phase HF to determine the effectiveness of the chemical treatment in removing unwanted interferences while preserving the binding medium. A second method of chemical treatment, using in situ generation of HF gas from acidified sodium fluoride, proved equally effective while minimizing the hazards of handling and storing liquid HF solutions. The success of the technique in removing mid-infrared interferences in binding medium analysis is demonstrated on various paintings dating from the 19th and 20th centuries.

Synergistic use of Py–THM–GCMS, DTMS, and ESI–MS for the characterization of the organic fraction of modern enamel paints

In this study, mass spectrometric techniques (THM–Py–GCMS, DTMS and ESI–MS) have been used to characterize the organic fraction of early twentieth century oil-based enamel paints. Analysis has been carried out on dry and liquid samples from historical reference paints, and on color swatches from commercial paint brochures, with a special focus on Ripolin. This renowned French brand of enamel paints, manufactured for household and other uses since 1897, was reportedly used by many avant-garde artists. Confirming the presence of enamel paint such as Ripolin in early twentieth century artworks scientifically through binding medium analysis is challenging because, until the end of the Second World War, the most widely used house paints were oil-based and chemically similar to artists’ oil paints. In addition, artists often modified/reformulated materials including oils, driers, industrial and house paints to customize their handling and optical properties. The challenge of identifying oil-based enamel paints on the basis of chemical composition is illustrated by the analysis of samples from two paintings by Wassily Kandinsky and Pablo Picasso. Analysis demonstrated that the organic fraction of Ripolin paints is typically composed of heat-bodied linseed oil in mixture with variable amounts of diterpene (Pinaceae) resin, in accordance with the industrial technical literature of the time. Comparative analyses of Lefranc artists’ tube paints suggested a more variable composition with respect to the type(s) of oil and their pre-treatment, and showed the presence of Pinaceae resin at trace levels only in two cases. Beeswax was detected in one of the tube paints tested. The results of this study indicate that complementary information can be obtained from the study of liquid paint from cans and dried paint-outs, while the media of painted brochures may differ from the original formulation as those were designed for expediency of drying and aesthetics. The results also elucidate how formulations and processing technology influence the physical and drying properties of oil-based enamel paints, in comparison with contemporary artists’ oil tube paints. Further research on a broader range of reference materials should help in the development of refined strategies for characterizing oil-based paints from the early twentieth century.

An insight into the metal coordination and spectroscopic properties of artistic Fe and Fe/Cu logwood inks

Fe- and Fe/Cu-based logwood inks were synthesized following recipes in nineteenth and early twentieth century manuals and were characterized by EPR, ESI-MS, FTIR, and Raman spectroscopies. This multi-technique approach allowed us to shed light on the structures of the complexes responsible for the inks’ colors and to obtain vibrational signatures that can be used to identify the different inks in works of art and in historic documents. Information on the nature and chemical properties of the complexes formed between a dye and a mordant is important as these determine, at least in part, their lightfastness. EPR permitted to determine the coordination environment of the metallic ions. The results of the ESI-MS analysis demonstrated, for the first time, the breakdown of the hematein molecule during the ink preparation, and that the colorants are formed by the complexation of the metallic ions by hematein breakdown products, mainly catechol and/or bicyclic compounds. The FTIR spectra obtained were found to be dominated by bands due to the binding medium and sulfates used as reagents. The Raman analysis showed that the characteristic features for the different inks studied depend on the historic recipe used, attesting to the challenges that their identification and characterization in works of art present. In the Raman spectra of the inks applied on paper, broadening of bands in the 750–400 cm−1 range are observed when compared to the spectra of the inks’ powders, possibly due to the interaction of the compounds with the cellulose in the substrate.

Interpretation of mid and near-infrared reflection properties of synthetic polymer paints for the non-invasive assessment of binding media in twentieth-century pictorial artworks

The goal of this paper is to evaluate the potential of reflection infrared spectroscopy in discriminating among different binding media in 20th century painting, with relation to distortion effects due to the mixing of surface and volume reflection and potential overlaps by pigment absorption bands. The study was carried out analyzing the reflection infrared properties of modern paint reconstructions including acrylic emulsion, polyvinyl acetate resin, oil-modified alkyd resin and two traditional media (drying oil and proteinaceous tempera) in mixture with a number of pigments selected for their absorption bands and their potential overlaps in the mid and near-infrared regions. Specific spectral markers were determined for each binding medium and then successfully exploited for the interpretation/classification of non-invasive reflection infrared spectra recorded in situ on eleven paintings of the second half of the twentieth century.

An investigation into the separation and migration of oil in paintings by Erik Oldenhof

The observation of disfiguring yellow oil-like material on the surface of paintings by the contemporary Dutch artist Erik Oldenhof led to an investigation of the material and environmental factors causing the migration and surface deposition of the exudate. A combination of material analysis, the examination of artificially aged reconstructions and information provided by the artist and paint manufacturer, Royal Talens, provided evidence that the phenomenon is related to the drying properties of the safflower oil used, the artist's use of thick paint layers and the availability of light while the paint is drying. Reconstructions demonstrated that the exudation phenomenon can be reproduced and is not restricted to one particular range of oil paint or manufacturer.Visual characteristics of the exudate, including its appearance in UV light and SEM back-scattered images, were documented, and the organic and inorganic components of the paint were characterised by SEM-EDX, XRF, THM-PyGC-MS and FTIR. Results confirmed that the exudate is composed of safflower oil derived from the paint binding medium, and that a difference in P/S ratio between the exudate and paint bulk is due to the presence of metal stearates in the paint that have not migrated to the surface.

Analysis on Mural Structures and Components of the Tombs in Liao Dynasty (A.D. 907–A.D. 1125)

The compositions of plaster, pigments, and binding medium were identified using micro-Raman spectroscopy, scanning electron microscopy coupled with energy-dispersive X-ray, and gas chromatograph-mass spectrometer. The results show that the plaster was calcium carbonate; the red color was ascribed to hematite; the blue pigment was ultramarine; the black pigment was carbon; and the yellow pigment was litharge. Animal glue as the binding medium was mixed in the pigments. Dissolved salt (mirabilite) was confirmed on the tomb passage. The mural detachment was detected with portable infrared thermal imager, and this damage resulted from the soil layer. This will serve as the basis for repairing the murals and reliable methods for identifying ancient murals.

Egg yolk identification and aging in mixed paint binding media by NMR spectroscopy.

NMR spectroscopy is a powerful analytical tool for the identification and quantitative analysis of organic materials in a cultural heritage context. In this report, we present an analytical NMR protocol for the identification and semiquantification of egg yolk binders and mixed binding media that also contain a drying oil, namely linseed oil. The samples studied have been artificially and/or naturally aged in order to simulate the composition of organic materials in paintings. Analysis of the 1D and 2D NMR spectra showed that egg yolk can be identified even in binding media of considerable age via signals originating from cholesterol and/or cholesterol oxidation products present in the aged binding medium. Based on cholesterol-related and other lipid signals in the NMR spectra of egg yolk binders, a molecular marker (R/F) that suggests the presence of egg yolk in paint binders is proposed. Via this marker, the presence of egg yolk in the organic material obtained from an early 18th century Greek icon is confirmed, and this is further verified by 2D NMR spectroscopy. It is demonstrated that NMR molecular markers developed to estimate the hydrolysis/oxidation state of oil paintings are also suitable for the analysis of egg yolk and mixed medium (egg yolk-linseed oil) binders, indicating the generality of the NMR methodological approach in the analysis of organic materials in a cultural heritage context.

An antimicrobial peptide screened from casein hydrolyzate by Saccharomyces cerevisiae cell membrane affinity method

A Saccharomyces cerevisiae cell membrane affinity screening method was developed to separate targeted antimicrobial peptides from the pepsin hydrolyzate of bovine casein. S. cerevisiae cell membranes were first immobilized on the surface of the silica gel to construct an affinity binding medium. A membrane-binding fraction was successfully screened by comparing the RP-HPLC fingerprint chromatograms of the hydrolyzate before and after adsorption with the adsorption medium. The amino acid sequence of the peptide was identified as LRLKKYKVPQL with the use of a matrix-assisted laser desorption/ionisation quadrupole time-of-flight tandem mass spectrometer. The sequence corresponded to amino acid residues 99–109 of bovine αS1-casein. The results indicated that it is feasible to target screen antimicrobial peptides from protein hydrolyzate using S. cerevisiae cell membranes. The influences of thermal treatment, pH, ions, and enzymes on the activity of the purified peptide were also determined. The activity of the peptide was relatively thermally stable and was pH dependent. It retained more than 90% of its activity in the presence of 15% Na+, K+ and pepsin. Trypsin, proteinase K, divalent cation Mg2+ and Ca2+ reduced the activity to different extents. The peptide also showed antibacterial effectiveness in fresh pear juice. These observations provide further information on the application of protein-derived antimicrobial peptides in food systems.

Searching for blood in Chinese lacquerware

In various historical Chinese sources pigs' blood is described as a binding medium for the ground layers of Chinese lacquerware [1–3]. This paper gives an overview of some approaches used to verify...