CNRS Research Laboratory for Historical Monuments

Champs-sur-Marne, France

CNRS Research Laboratory for Historical Monuments

Champs-sur-Marne, France
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Tiennot M.,CNRS Research Laboratory for Historical Monuments | Mertz J.-D.,CNRS Research Laboratory for Historical Monuments | Bourges A.,CNRS Research Laboratory for Historical Monuments
Rock Mechanics and Rock Engineering | Year: 2017

Flaking is a well-known pattern on rich clay stone. As swelling of clay minerals may induce crack propagation under fatigue, a fracture mechanics approach is proposed to investigate its impact on such decay pattern.A clay-bearing sandstone from the Thüringen region is studied because of the scaling effect observed at its surface when exposed to environmental conditions. Semi-circular bending specimens adapted to stone heritage studies are prepared and three configurations are tested, in order to measure toughness with respect to the bedding of this sandstone. Deformations are measured during relative humidity variations. They are measured anisotropic due to position and orientation of the clay phases within the stone. The influence of such natural dimensional variations on Young modulus and fracture toughness is studied. It appears that the induced damage is oriented and is the consequence of opening of the initial microcracks in the direction perpendicular to the maximum swelling. This damage induces an evolution of the fracture properties and behaviour. Toughness decreases as relative humidity increases depending on the orientation of the microcracking. Moreover, the toughness anisotropy of this sandstone appears during humidification. After several cycles of swelling, the microcracking induces an increase in toughness when notch is perpendicular to them. This may explain some stone deterioration patterns, as flakes subparallel to the stone surface. © 2017 Springer-Verlag GmbH Austria

Rocca E.,CNRS Jean Lamour Institute | Mirambet F.,CNRS Research Laboratory for Historical Monuments
Journal of Solid State Electrochemistry | Year: 2010

From technical and industrial heritage, curators are in charge of numerous and important collections of metallic items which are representative of the industrial and technical development of our societies. The diagnosis of the conservation state and the choice of the restoration treatment are important questions that have to be solved by curators to avoid expensive restoration works. This paper proposes to show how simple electrochemical techniques can be used as an efficient tool to contribute to the diagnosis of the conservation state of metallic artefacts and to monitor the restoration treatment through three examples. In the case of the very-corroded aluminium alloys of aircraft belonging to the Air and Space Museum (Le Bourget, France), stationary electrochemical measurements are able to characterise the allowable electrochemical effect of thick corrosion layer on the corrosion rate of metal but are not sufficient to give a complete diagnosis. In contrary, for the bronze part of the miner's lamp collection of the Mining History Centre of Lewarde, France and the nickel-plated steel of an ancient typewriter of the Musée des Arts et Metiers, Paris, France, an inhibition treatment based on sodium carboxylate within the framework of temporary conservation treatment was applied with success, on the basis of the electrochemical results obtained in the present study. © 2009 Springer-Verlag.

Bonose-Crosnier de Bellaistre M.,University Paris - Sud | Nowik W.,University Paris - Sud | Nowik W.,CNRS Research Laboratory for Historical Monuments | Tchapla A.,University Paris - Sud | Heron S.,University Paris - Sud
Journal of Chromatography A | Year: 2011

Chromatographic study of natural products helps to determine their molecular composition and to identify their sources (biological, geographical, etc.). However, identifying anthraquinoids is still a challenge because this chemical family is composed of more than half a thousand molecules. In the present work, a series of C18 stationary phases were systematically studied to evaluate their separation potential for these compounds in high performance reversed phase liquid chromatography (RPLC). The stationary phases with various physicochemical properties were evaluated with respect to the separation of 30 standards. Selectivity of the studied stationary phases and symmetry of the obtained peaks were chosen as the evaluation criteria. Calculations of symmetry and separation capacity parameters have been proposed. These parameters are not dependent on the dimensions of the columns and were used for the classifications of phases. In conclusion, this study is intended to be a guide as to which stationary phases analysts can use for resolving separation of a complex mixture of anthraquinoids. © 2010 Elsevier B.V.

Nowik W.,University Paris - Sud | Nowik W.,CNRS Research Laboratory for Historical Monuments | Bonose-Crosnier de Bellaistre M.,University Paris - Sud | Tchapla A.,University Paris - Sud | Heron S.,University Paris - Sud
Journal of Chromatography A | Year: 2011

A series of reversed phases bonded with several functional groups was investigated for separation of anthraquinone derivatives, following the previous work, dedicated to the selectivity of octadecyl silica bonded phases. Considering wide diversity of substitutions in hydrophobic anthraquinone skeleton, interactions like dipole-dipole, π-π or H-bond acceptor/donor, as well as inclusion complexes formation can be employed to improve separation. In this study, several phases with grafts like cyano, nitro, aromatic, PEG, diol, calixarene and cyclodextrin were used with water-acetonitrile gradient for separation of thirty anthraquinoids' standards. The evaluation of performances was measured using the symmetry parameter and the number of critical pairs of peaks formed. The results point out the aromatic and calixarene bonded silica as the most interesting in terms of symmetry and critical pairs number. Finally we tested the performance of Caltrex Resorcinaren, Pursuit XRs DP and Luna Phenyl-Hexyl on real samples of anthraquinone natural dye extracted from a red thread taken from a 15th C. tapestry. We observed and compared the retention behaviour of some new anthraquinoids additional to our standards set and showing behaviour particular to substituted anthraquinone carboxylic acids. © 2011 Elsevier B.V.

Tong Y.,University Paris Est Creteil | Bouteiller V.,University Paris Est Creteil | Marie-Victoire E.,CNRS Research Laboratory for Historical Monuments | Joiret S.,University Pierre and Marie Curie
Cement and Concrete Research | Year: 2012

The aim of this study was to assess the efficiency of a realkalisation treatment using sacrificial anodes applied to reinforced concrete degraded by carbonation. Analytical determinations (acid/base indicators, quantitative pH, alkaline profiles, SEM and micro-Raman) together with electrochemical characterizations (rest potential, impedance, linear polarisation resistance and corrosion current densities) were performed on artificially carbonated slabs, before and after treatment (mainly 15 days, 11 weeks, 6 and 12 months). The treatment efficiency was demonstrated by an increase of pH and by an alkaline ion penetration in the concrete cover. Rest potential and corrosion current densities indicated a slight decrease of the rebar corrosion activity. Complementary Raman spectroscopy showed a change in the oxide species and SEM observations indicated that the cement matrix remained almost unchanged. © 2011 Elsevier Ltd. All rights reserved.

Surowiec I.,Umeå University | Nowik W.,CNRS Research Laboratory for Historical Monuments | Moritz T.,Swedish University of Agricultural Sciences
Dyes and Pigments | Year: 2012

Analysis of natural dyes in historical objects is important for both conservation purposes and to determine the origin and culture that produced it. Identification of a particular dye is usually made based on the presence of its main components, while consideration of minor components is important for differentiating between dyes originating from closely related species. Tyrian purple is one of the oldest dyes known to man and derives from different species of marine molluscs. In all of these species, indigotin, indirubin and their brominated analogues are the main colouring compounds. Here, we describe the identification of minor indigoids found in extracts of the pigment obtained from one of the Tyrian purple species, Hexaplex trunculus. Identification of these compounds was made based on isotopic patterns and accurate mass measurements of protonated molecular ions and their high collision energy fragments obtained in LC-MS/MS experiments. The unknown compounds appeared to be analogues of indirubin and its mono- and dibrominated derivatives with one CO group in the indirubin backbone substituted by a CNH group. Identification of these compounds facilitates the detection of dyestuffs from H. trunculus in historical objects and increases our knowledge about the dye biosynthesis and technology of Tyrian purple production. © 2012 Elsevier Ltd. All rights reserved.

Anglos D.,Foundation for Research and Technology Hellas | Anglos D.,University of Crete | Detalle V.,CNRS Research Laboratory for Historical Monuments
Springer Series in Optical Sciences | Year: 2014

A versatile spectrochemical technique enabling nearly instant, multi-element analysis of materials, LIBS is increasingly employed in studies of archaeological and historical objects, monuments and works of art. The development of several mobile LIBS instruments opens a lot more possibilities for analytical campaigns on site: at museums, conservation laboratories and even outdoors at excavation sites or historical monuments. The basic concepts underlying the use of LIBS in the context of cultural heritage studies are briefly reviewed along with technical and instrumentation aspects. Selected examples of analytical studies are discussed with emphasis on cases that demonstrate the use of mobile LIBS instruments. © 2014 Springer-Verlag Berlin Heidelberg.

Lattuati-Derieux A.,CNRS Research Laboratory for Historical Monuments | Thao-Heu S.,CNRS Research Laboratory for Historical Monuments | Lavedrine B.,CNRS Research Laboratory for Historical Monuments
Journal of Chromatography A | Year: 2011

Polyurethane foams are widely present in museum collections either as part of the artefacts, or as a material for their conservation. Unfortunately many of PU foam artefacts are in poor condition and often exhibit specific conservation issues. Their fast thermal and photochemical degradations have been the aim of previous researches. It is now accepted that hydrolysis predominates for polyester-based polyurethane PU(ES) whereas oxidation is the principal cause of degradation for polyether-based polyurethane PU(ET) variety. Only a few studies have been devoted to volatile organic compounds (VOCs) emitted by polyurethanes and, to our knowledge, none were performed on polyurethane foams by using headspace-solid phase microextraction (HS-SPME). The objective of the work described here is to assess the impact of some environmental factors (humidity, temperature and daylight) on the degradation of PU foams by evaluating their volatile fractions. We investigated morphological changes, polymerized fractions and volatile fractions of (i) one modern produced PU(ES) foam and one modern PU(ET) foam artificially aged in different conditions as well as (ii) four naturally aged foams collected from various daily life objects and selected for the representativeness of their analytical data. Characterization procedure used was based on attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR), pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) and non-invasive headspace solid-phase microextraction coupled with gas chromatography and mass spectrometry (HS-SPME-GC/MS). In this paper, the formation of alcohol and acid raw products for PU(ES) and glycol derivatives for PU(ET) during natural and artificial ageing is confirmed. These main products can be considered as degradation markers for PU foams. Results show that artificial and natural ageing provide similar analytical results, and confirm that the dominant degradation paths for PU(ES) and for PU(ET) are hydrolysis and photo-oxidation, respectively. Lastly, we highlight that non-invasive HS-SPME-GC/MS analysis allows to distinguish between PU(ES) and PU(ET) at any point of their degradations. © 2011 Elsevier B.V.

Nowik W.,CNRS Research Laboratory for Historical Monuments | Marcinowska R.,University of Warsaw | Kusyk K.,University of Warsaw | Cardon D.,University Lumiere Lyon 2 | Trojanowicz M.,University of Warsaw
Journal of Chromatography A | Year: 2011

Attempts at identification of mollusc species producing Tyrian purple from archaeological material are usually done with high performance liquid chromatography in the reversed-phase system, but the peaks obtained are often wide and asymmetric. This is due to the low solubility of the indigoids and their brominated derivatives in the mobile phase, especially 6,6′-dibromoindigotin, which is soluble in only few, particular solvents. Our study focused on improving both symmetry and peak height for more precise quantification. The influence of various factors was evaluated: stationary phase characteristics, mobile phase composition, elution gradient parameters and temperature on the peak shape of the main components of Tyrian purple. The best results were obtained using highly retentive, but moderately bonded ODS stationary phases (about 2.8μmolm-2), percolated with gradient of acetonitrile with acidified aqueous mobile phases (0.1% strong acid) at elevated temperatures (70°C). The upper quantification limit for 6,6′-dibromoindigotin was improved by over 350%, between standard and optimised systems. Using them, the detection and quantification of trace Tyrian purple components (less than 0.15%) aside from major indigoids becomes possible. Consequently, for the first time, the new analogues of brominated and unbrominated indirubins were found in the shellfish purple from Hexaplex trunculus. © 2011 Elsevier B.V.

Bourges A.,CNRS Research Laboratory for Historical Monuments | Verges-Belmin V.,CNRS Research Laboratory for Historical Monuments
Materials and Structures/Materiaux et Constructions | Year: 2011

An European enquiry revealed that workability and adhesion of poultices is the main criteria for conservators to select poultice recipe. The poultice needs first to adhere to the substrate and be easy to use and prepare before presenting a real effect on salt extraction. However, a procedure to test the consistency and workability of fresh poultices does not exist neither in practice nor is it documented. Users usually rely on their empirical know-how to determine the most adapted consistency of poultices for a given type of substrate. The purpose of the following study was to scientifically determine the consistency and workability of fresh poultices. A test procedure was adapted from the fields of mortar, cement and concrete. In the same way as for cement and mortar standards, poultices can be classified in different categories according to their composition. It has been demonstrated that the determination of consistency helps to optimise poultice water content, while the workability has a direct influence on the adhesion of the poultice to the substrate. The knowledge of these properties is essential to determine the best conditions for a desalination treatment. Finally, optimal ranges of consistency and workability are established for the main categories of poultices (cellulose and mineral) and may help end-users to improve their own poultice recipes. Shrinkage limits of poultices are determined to insure their good adherence of the substrate during drying. © RILEM 2010.

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