Papers by Costanza Miliani
Heritage Science, 2020
Maya blue is a hybrid pigment where an organic component, indigo, is incorporated in a porous cla... more Maya blue is a hybrid pigment where an organic component, indigo, is incorporated in a porous clay. Despite its widespread use in the Mesoamerican artistic production and numerous studies devoted to understand the type of interactions between indigo and the host framework, its technology has not been completely unravelled yet. In this study portable non-invasive UV–vis reflection spectroscopy is proposed as a robust method for in situ investigation of Maya blue pigments. Laboratory mock-ups of powder Maya blue have been prepared employing different synthesis procedures (varying the nature of: clays, indigo–clay ratios, heating temperatures and time). The goodness of the prepared Maya blue samples—namely the occurrence of indigo–clay interactions—have been probed by micro-Raman spectroscopy and related UV–vis spectral markers have been identified. DFT calculations as well have been performed to deeply explain UV–vis profiles. The set of spectral markers have been finally exploited to...
Procedia Chemistry, 2013
In 1946 TAM (Taller de Arte Mural) a group of famous Argentine artists namely Castagnino, Spilimb... more In 1946 TAM (Taller de Arte Mural) a group of famous Argentine artists namely Castagnino, Spilimbergo, Urruchúa and Colmeiro, realized the decoration of four lunettes placed above the entrances of the Galerías Pacífico in Buenos Aires. Twenty-four samples coming from these lunettes have been analyzed by means the infrared transmission micro-spectroscopy to determine the composition of the preparation layer (mainly composed by gypsum) and the nature of binder (a drying oil), while the investigation of Raman micro-spectroscopy has allowed to identify the inorganic pigments and the synthetic organic dyes present.
Talanta, 2006
Research work using a compact and portable fiber optic mid-infrared reflectance spectrometer has ... more Research work using a compact and portable fiber optic mid-infrared reflectance spectrometer has been carried out to study surface materials on marble, first on laboratory reference models and then on historical objects. The laboratory research has shown that the complex optical reflectance phenomena of layered samples can be interpreted in terms of the nature of the compounds present (sulfates, oxalates, phosphates, resins, waxes and proteins were studied) even with a very low signal overlapping with the strong carbonate reflectance. The portable instrument was used for in situ examination of the surface condition of two Italian marble works of art: the Deposizione dalla Croce by Benedetto Antelami in the Parma cathedral and the David by Michelangelo in the Galleria dell'Accademia in Firenze.
Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, 2009
The palette used in two paintings by Paul Cézanne, L&... more The palette used in two paintings by Paul Cézanne, L'étang des soeurs dated c. 1875 and La route tournante, made in the last year of his life (1902), were analyzed using non-invasive spectroscopic methods. X-ray fluorescence combined with principal components analysis (PCA) and supported by reflectance near- and mid-FTIR was shown to be a powerful analytical tool to draw conclusions about the chemical identification of inorganic materials in paintings. Pigments and fillers such us Thénard's blue, Prussian blue, red ochre, kaolin, vermilion, lead white, zinc white and barium sulphate, were identified. Evidence for three different pigments, namely a copper arsenite pigment, chrome green (a mixture of chrome yellow and Prussian blue) and viridian has been obtained by the PCA analysis of elemental compositions of green hues.
Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, 2009
In situ, non-invasive investigations by means of portable X-ray fluorescence and fibre optic refl... more In situ, non-invasive investigations by means of portable X-ray fluorescence and fibre optic reflectance mid-infrared (mid-FTIR) spectroscopy of painted Böttger Stoneware objects have been carried out through the MOLAB transnational access to the Porcelain Collection of the Staatliche Kunstsammlungen in Dresden. It has been possible to gather information regarding the composition of the black glaze by applying a principal component analysis to the elemental analysis to distinguish between the variations of lead, iron and manganese compositions of each glaze. It has been furthermore feasible to combine molecular spectroscopy for characterization of the constituent painting materials, namely lead white as cerusite and hydrocerusite, the use of cinnabar, azurite and Prussian blue leading to a better knowledge of the state of conservation and utility of certain pigments that may give rise to chronology of the decorative artwork. The identification of oxalates namely whedellite and moolooite are assigned as degradation products relative to the decorative areas.
Physical Chemistry Chemical Physics, 2010
A DFT-TDDFT investigation on the aluminium complexation of apigenin and luteolin has been carried... more A DFT-TDDFT investigation on the aluminium complexation of apigenin and luteolin has been carried out. We have focused our attention on these hydroxyflavonoids, which are the main components of weld, one of the earliest natural dyestuff used in art. In particular, weld, upon complexation with Al(iii) forms a highly prized lake which has been widely used in medieval manuscripts and easel paintings for its rich yellow colour and transparency. The experimental spectra of apigenin and luteolin upon addition of increasing [Al(3+)] show a general red-shift of the lowest absorption bands of both flavonoids spectra, associated with the presence of two and three isosbestic points for apigenin and luteolin, respectively. The molecular geometries of all the Al-apigenin and -luteolin complexes have been optimized, followed by calculation of the formation Gibbs free energies and UV-vis absorption spectra. The comparison between the computed absorption spectra of the Al-flavonoid complexes and the experimental ones corresponding to various limit [Al(3+)] concentrations has been used to discriminate between the possible complexation modes as well as the stoichiometry ratio. We have thus been able to associate specific Al-apigenin (-luteolin) complexes with the experimental absorption spectra as a function of the [Al(3+)] concentration, thus providing insights into the aluminium complexation of these hydroxyflavonoids and most importantly into the weld lake composition.
Journal of Raman Spectroscopy, 2009
Resonance Raman spectroscopy has been utilized to identify vegetal and animal dyes and lakes. The... more Resonance Raman spectroscopy has been utilized to identify vegetal and animal dyes and lakes. These compounds have been used by artists since antiquity, and their identification has important implications in art history and conservation. The resonance condition is useful when working with real ancient objects so as to enhance the Raman scattering of chromophores with respect to the strong signal of the matrix, such as the textile or parchment over which the colorant is supported. The strong fluorescence that generally characterizes the resonance Raman spectra was eliminated by using subtracted shifted Raman spectroscopy (SSRS). A systematic study on reference organic dyes was primarily carried out to evaluate the suitability of the method and to estimate the strengths and limitations of the spectrum reconstruction process. The method was then applied to the noninvasive identification of madder on ancient dyed silk textiles such as an altar table cloth and a manutergium attributed to...
Journal of Raman Spectroscopy, 2004
ABSTRACT
Journal of Raman Spectroscopy, 2011
... 6 ENEA (Italian National Agency for New Technologies, Energy and Sustainable Economic Develop... more ... 6 ENEA (Italian National Agency for New Technologies, Energy and Sustainable Economic Development), Casaccia Research Centre, Via Anguillarese 301, 00123 S.Maria di Galeria, Rome, Italy. Email: C. Miliani (miliani@thch.unipg.it). ...
Journal of Raman Spectroscopy, 2008
The objective of this study was to evaluate the use of micro‐Raman spectroscopy as a non‐invasive... more The objective of this study was to evaluate the use of micro‐Raman spectroscopy as a non‐invasive vibrational spectroscopic technique applied to the examination of wool samples, which may be applied to textile materials of cultural heritage interest. In this work, a selection of wool materials were primarily investigated in their unaged states through the utility of a natural wool reference together with selected samples dyed with different natural colorants, namely woad, weld and madder. The identification of the main modes of vibration of the wool fibre keratin was assessed in all the samples, which aided the determination of the changes within the protein structure, in particular, through the cysteine and peptide cross‐linkages brought about by the addition of the dyes that can produce effects similar to degradation. The dye too was assessed importantly to enable its identification through its characteristic scattering or fluorescence emissions on a woollen matrix, as well as to ...
Journal of Non-Crystalline Solids, 2007
Tin-opacified lead glaze, prepared according to Renaissance recipes, has been fired at different ... more Tin-opacified lead glaze, prepared according to Renaissance recipes, has been fired at different temperature from 300°C to 990°C, and investigated by Raman scattering. A chemometric treatment and a systematic curve-fitting procedure have been applied in the range of 700-1250 cm À1 in order to monitor quantitatively the structural changes of the silicate network that occurred with firing. The results obtained on model glazes are compared with Raman spectra collected on various Renaissance potteries. This method is suggested for non-invasive surface analysis of ancient glazes aimed at the characterization of processing techniques.
Journal of Cultural Heritage, 2007
The history of use of lead–tin yellow is complex due to the existence of two forms, namely type I... more The history of use of lead–tin yellow is complex due to the existence of two forms, namely type I and type II, that where first differentiated by Kühn only around the 1970 [1]. Type I is lead stannate, Pb 2 SnO 4 , whose structure has been determined by X-ray diffraction, neutron ...
Journal of Cultural Heritage, 2007
... Obviously it would be of interest to continue monitoring these monuments in the future to eff... more ... Obviously it would be of interest to continue monitoring these monuments in the future to effectively understand the endurance of the artificial oxalate. References. [1] JV Liebigs, Annalen Chemie und Pharmazie LXXXVI (1853), p. 113. ...
Journal of Archaeological Science, 2014
The Madrid Codex, one of only a few existing pre-Hispanic Maya codices that survived the Spanish ... more The Madrid Codex, one of only a few existing pre-Hispanic Maya codices that survived the Spanish destruction, has been analysed in situ at the Museo de América in Madrid by means of an array of noninvasive techniques. This investigation has provided information concerning the colouring materials used in its manufacture, namely calcium carbonate, red ochre, vegetal carbon black and Maya blue pigments observing bright blue to grey hues. A discussion of archaeological implications of the materials identified, as well as some comparative observations with those previously acquired on the Central Mexican Codex Cospi have been addressed.
Journal of Archaeological Science, 2012
Ancient Mesoamerican codices represent the religious and historical legacy of the pre-Columbian p... more Ancient Mesoamerican codices represent the religious and historical legacy of the pre-Columbian people, they were produced to record the historical and religious matters. Codex Cospi, a divinatory book, is one of the fifteen extant pre-Hispanic Mesoamerican books which survived the destruction of the Spanish conquest. Thanks to the use of a set of portable non-invasive analytical techniques it was possible to study the Codex Cospi revealing valuable information on its constituting materials (dyes, pigments and substrates). The analytical results were compared with historical references contained in early colonial Mexican documents showing interesting parallels and providing hints for probable identification of colouring materials.
Chemical Physics Letters, 2008
Ultramarine blue pigments (in the form of highly concentrated KBr discs) have been examined by tr... more Ultramarine blue pigments (in the form of highly concentrated KBr discs) have been examined by transmission infrared spectroscopy. Evidence of entrapment of carbon dioxide in the natural pigment from Afghanistan was indicated by the absorption band at 2340cm− ...
Applied Spectroscopy, 2008
The prototype of a portable instrument, based on the time-correlated single-photon counting metho... more The prototype of a portable instrument, based on the time-correlated single-photon counting method, purposely assembled for in situ measurements of luminescence lifetimes on artwork surfaces, is here presented. Preliminary tests have been carried out using the portable instrument and the results have been compared with those obtained using a bench instrument. In this way we have proven that the prototype provides lifetime measurements with good precision. It is also shown that fluorescence lifetime determinations, coupled with steady-state fluorescence spectra, allow the distinguishing, on laboratory samples, of different red organic lakes having similar fluorescence spectra, achieving new boundaries in the nondestructive diagnosis of artwork materials. The first in situ application of the technique on an original work of art, The Book of Kells, held at Trinity College Library, Dublin, highlighted the diagnostic potential of coupled steady-state and time-resolved luminescence spectroscopy in the identification of organic colorants.
Applied Spectroscopy, 2009
The variations of the fluorescence emission of carmine lake travelling through an absorbing and s... more The variations of the fluorescence emission of carmine lake travelling through an absorbing and scattering medium, such as a paint layer, were investigated by ultraviolet (UV)–visible absorption, fluorescence spectroscopy, and imaging techniques. Samples of the lake were studied in dilute and saturated solutions, on a reference test panel and a real case study. Relevant spectral modifications have been observed as a function of the lake concentration mainly consisting of a fluorescence quenching, red shift of emission maxima, and deformation of emission band. The application of a correction factor based on the Kubelka–Munk model allowed fluorescence spectra obtained in solution and on painted samples of known composition to be compared and correlated, highlighting that the fluorescence of the lake within paint layers is affected by both self-absorption and aggregation phenomena. This approach has been successfully applied on a painting by G. Vasari for the noninvasive identification...
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Papers by Costanza Miliani