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In this work, it is reported that thermal analysis techniques such as TG, DTA and X-ray thermodiffraction, performed in air or nitrogen atmosphere, are very useful for evaluating and characterizing the pigments and the supports used for the manufacture of wall paintings from the San Isidoro del Campo Monastery (fifteenth century) in which different scenes from the life of San Jeronimo are represented. The use of thermal techniques has allowed for collecting information on the technology and raw materials used in the manufacture of these wall paintings. The composition of the different colours forming the wall paintings is the following: blue by azurite, green by atacamite, red by iron oxide (hematite), cinnabar and ochre by iron oxyhydroxides (goethite), black by carbon and white by calcite. In all the colours, calcite and quartz were also identified. The paintings were performed by using the fresco technique. The support mortars are constituted of calcite, quartz and straw. [ABSTRACT FROM AUTHOR]

In this work, it is reported that thermal analysis techniques such as differential thermal analysis and thermogravimetric analysis are very useful for evaluating metals threads and fibres used in the manufacture of historical artifacts. Thermal analysis has been used to characterize the silk, cotton and linen employed as supports and the copper, silver and aluminium as the metallic components in the studied threads. Other organic compounds, mainly added for the conservation of the threads, have also been characterized. [ABSTRACT FROM AUTHOR]

The majority of the studied artworks were altarpieces, sculptures and/or wood-based works from different periods. Non-traditional gilding techniques have been first described in this paper, such as those that employ materials as oil in the gilding on bole, glue and bole with lead white in mordant gilding, vermilion in the preparation layers; and brass gilding or those with aluminium, lead chromate, mica or corla trying to imitate the golden hue in restoration or repaint processes. For the determination of the composition of the different gilded layers, spectroscopic techniques, such as FTIR and micro-Raman, and SEM-EDX elemental chemical analyses were successfully used. [ABSTRACT FROM AUTHOR]

This study attempts to establish the advantages and limitations of the combined use of portable UV–Vis-FORS and XRF-XRD portable equipment for the non-invasive characterisation of pigments from Roman wall paintings from Seville, Spain, dated to the first and second century AD. XRD revealed the presence of calcite, dolomite and aragonite, indicating the colour white. Egyptian blue was identified using FORS and XRF, and additional information was obtained with XRD. For the colour green, FORS and mainly FTIR and colorimetry enabled the distinction between glauconite and celadonite, although other techniques were necessary to classify all components of the green areas by determining the presence of cuprorivaite, chlorite and chromium. For the colours yellow and red, the presence of goethite, yellow ochre, cinnabar and haematite was confirmed using FORS and XRF in some cases; the results were corroborated by XRD. Chromatic characterisation and the values of inflection points of FORS spectra enabled a better differentiation between reddish colours (orange, brown, purple and pink). The XRD and XRF techniques revealed that violet was created by mixing red haematite and Egyptian blue and slight variations in FORS spectra confirmed this. [ABSTRACT FROM AUTHOR]

This work suggests a way of differentiation between the natural or synthetic origin of inorganic materials that were historically used in the Cultural Heritage field. An exhaustive review of different reported procedures of synthesis of pigments was conducted, as well as a review of the accompanying minerals in case of natural pigments. The natural or synthetic origin of the pigments studied in this work was performed through the characterization of the accompanying minerals, in the case of the natural pigments, or the trace elements that are present as part of synthesis by-products or washing/purifying reagents and/or reactants that have only been partly removed in the final steps of these processes. This work characterized red pigments due to their wide variety, complexity and possibility of use in different mixtures. The following pigments were studied: cinnabar-vermilion, red lead and iron pigments. Also mixtures of these pigments between them and with red lake were also studied. Natural cinnabar was accompanied by silicon oxide (opal, chalcedony or quartz), calcite, clay minerals and, sometimes, pyrite. K together with S indicated a synthetic pigment (vermilion) obtained through the wet method. Nevertheless, K has not been found in layers containing only vermilion in our samples. The presence of Sn in some cases indicated vermilion that came from the dry process. K from the synthesis always appeared in the red lead pigment. The red natural ochre was confirmed by presence of clay minerals and iron. It should be said that Ca and S, and sometimes Al and K, were usually found in Mars red pigment. The presence of Al and Ca allowed the identification of carmine lake. [ABSTRACT FROM AUTHOR]

We report here a study of 30 fragments of green wall paintings from Roman times found in the Patio de Banderas excavation in Seville Alcazar. The sample characterisation was realised using optical microscopy, colourimetry, infrared and micro-Raman spectroscopy, X-ray diffraction, and scanning electron microscopy equipped with energy dispersive X-ray spectroscopy. The study of these pigments is important because it can help determine the source or the pictorial technique used. The samples studied in this work have been divided into two groups, according to the composition of their green pigments. In the first group, celadonite has been characterised as the primary component of the green colour; chlorite was also detected. Particles constituted by chromium accompanied by aluminium, iron and zinc were found in all studied samples of this group. Chlorite and chromium oxide could also be responsible for the green colour. The presence of chromium suggested the presence of green colour pigment from Verona. In the second group, a mixture of celadonite and glauconite was detected and could be responsible for the green colour observed. The addition of refracting material such as Egyptian blue was also used. A mixture of Egyptian green and Egyptian blue together with celadonite and glauconite was also found. Four classes of intonaco were recognised and classified based upon the composition of the aggregates. [ABSTRACT FROM AUTHOR]

Highlights: [•] Raman spectroscopy characterisation of the compounds used to produce polychrome wall paintings. [•] The reliability of Raman techniques (portable and μ-Raman). [•] Effects of the compounds that are formed on or added to the wall paintings in the Raman study. [•] Characterisation of the advantages of compounds from cross sections of the wall paintings. [ABSTRACT FROM AUTHOR]

The mainly use of infrared spectroscopy and colorimetry allowed the characterization of the pigments and compounds of the wall paintings from the Monastery of San Isidoro del Campo in Seville, dated on the 15th century. Calcite, quartz and albite were detected in the ground mortar layers. As pigments, red ochre, yellow ochre, paratacamite, atacamite, azurite and carbon black were used, and also lime as the binder, therefore the fresco technique was employed. Both FTIR-ATR and FTIR (in transmission) experiments were performed. Comparison between materials used in some of the wall paintings from Seville in this period was performed. The article revealed important information about wall paintings within a historical context related to the 15th century Catholic Reformation. [ABSTRACT FROM AUTHOR]

This work comprises an exhaustive study of Spanish decorative leathers dating from the 12th to 14th centuries. These paintings are considered a key example of a crucible of artistic styles: Gothic, Islamic and Florentine Trecento. The goal of this work was to use the scientific information provided by a number of experimental techniques – namely EDX, micro-FTIR, micro-Raman and micro-XRD – to assess the dating of the wooden vault, leather preparation and filling fibres. Another goal was to assess the artistic technique based on the characterization of pigments and the differentiation between original materials and those added throughout its history. Gypsum was the original preparation layer extended over the leather. A new preparation stratum was added in further interventions with the artwork. The original pictorial materials and those used during refurbishments have been identified. Original pigments were: red lead, Mars red, red lake, cinnabar, lapis lazuli, red ochres, raw sienna, white lead and charcoal black. Gilding was also found. Pigments added during restoration were: barite, emerald green, rutile, anatase, Mars red, cadmium red, lithopone, cadmium yellow, charcoal black and orpiment. • The study clarifies the leather decoration technique in Andalusian cultural heritage. • Original and later-added pigments are characterized and discriminated. • Natural and synthetic materials have been identified. • Wooden vault, leather and filling fibres are dated between 12th and 14th centuries. • This study confirms different interventions along the history. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Important historical metal threads studied by mainly non-destructive techniques. • Degradation compounds by degradation of animal fibers. • Degradation compounds by inappropriate application of chemicals. • We study a type of material which has not been widely studied. Abstract The degradation processes that occurred on metal threads applied in the embroidery used for clothing and in the ornamentation of sculptures, the Sevillian Holy Week processions, and Portuguese and Spanish palace and museum are thoroughly analyzed. Some threads from the 14th and 18–19th centuries were considered. In the metal threads, sulphur- and chlorine-based compounds were detected either individually or together, depending on the degradation process. Basic silver carbonate, sodium bicarbonate and copper-based compounds were also observed. The different degradation processes were attributed to different factors, such as environmental contamination, degradation of the fibrous cores, and inadequate cleaning and/or mechanical treatments. [ABSTRACT FROM AUTHOR]

Abstract: Novel controlled release formulations (CRFs) were developed for reducing leaching of herbicides and contamination of groundwater. The herbicide metribuzin (MTB) was entrapped within a sepiolite-gel matrix using a novel and ultrasound-based technique. Different sepiolite/herbicide matrices (either as a gel or as a powder after freeze-drying) were prepared with pesticide loading between 28.6 and 9.1%. The release of MTB from the control released formulations into water was retarded when compared with commercial formulation (CF), except in the case of the sepiolite-gel-based formulations with lower amounts of sepiolite. The rheological properties and microstructure of these formulations were examined in detail. FTIR spectra showed that there was no evidence of herbicide inside the sepiolite tunnels. The SEM micrograph of the sepiolite-gel-based formulations showed the fibrous morphology typical of sepiolite and no separate particles of MTB were found. However, the chemical analysis by EDX confirmed the presence of S, N, and C, which were attributed to MTB, together with the fibers of sepiolite. Rheological characterization indicated that samples containing MTB develops a microstructure, which is irrespective of concentration above 1 mass % sepiolite. There was a good agreement between the microstructure characteristics and MTB release behavior. [Copyright &y& Elsevier]