Nouveauté : Toutes les publications par laboratoires de l’UFR de chimie  regroupées
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H. Colboc, D. Bazin, S. Réguer, I. Lucas, P. Moguelet, et al.

Chemical characterization of inks in skin reactions to tattoo

Skin reactions are well described complications of tattooing, usually provoked by red inks. Chemical characterizations of these inks are usually based on limited subjects and techniques. This study aimed to determine the organic and inorganic composition of inks using X-ray fluorescence spectroscopy (XRF), X-ray absorption spectroscopy (XANES) and Raman spectroscopy, in a cohort of patients with cutaneous hypersensitivity reactions to tattoo. A retrospective multicenter study was performed, including 15 patients diagnosed with skin reactions to tattoos...

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M. Mobasher, M. Lancry, J. Lu, D. R. Neuville, L. Bellot-Gurlet, et al.

Thermal relaxation of silica phases densified under electron irradiation

The thermal relaxation of the silica metamict phase obtained after electron irradiation of 11 GGy Suprasil SiO2 glass was characterized using Raman spectroscopy and compared to silica densified under high Pressure and high temperature irradiated at 107 Gy. In parallel, we studied the densification relaxation kinetic by step isochronal annealing treatments. Starting from the metamict phase, local density indicators, D1 and D2 bands decreased quasi-monotonously under thermal treatment together with the glass density. However, for 107 Gy samples, we evidenced an anomalous sharp increase of D1 and D2 bands between 800°C and 1000°C, which could be interpreted as a transition from low-density amorphous (LDA) to a high-density amorphous configurational state (HDA). Interestingly after an annealing at 1000°C, the overall Raman signature indicates that the “relaxed metamict phase” exhibits a higher configurational disorder than pristine silica whereas 107 Gy samples simply relaxed towards pristine silica suggesting a low density amorphous megabasin with several minima.

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J. Burlot, X. Gallet, G. Simseik Franci, L. Bellot-Gurlet, P. Colomban

Non-invasive on-site pXRF analysis of coloring agents of under- and over-glazes:...

The study of rare objects requires the use of mobile non-invasive methods such as a portable X-ray fluorescence instrument (pXRF), but this involves an analysis from the outer surface, while the depth analyzed depends on the element measured and, in addition, the material can be very heterogeneous at different scales. The concept of elemental composition, therefore, has no "absolute" meaning for painted enamel decorations. This work evaluates this concept by comparing the pXRF measurements made with different configuration procedures, allowing to evaluate the consequences on the variability of the XRF signals, and discusses the contents of certain chemical elements. For this, two shards from the Qianlong period are analyzed, a shard of blue and white (underglazed) porcelain and a fragment of an 'imperial' bowl with painted enamel decoration (huafalang). The variability of measurements is compared for visually appearing homogeneous or heterogeneous areas.

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Caroline Salzemann

Élaboration raisonnée de nanomatériaux mono- et bimétalliques (HDR)

L'élaboration raisonnée de nanomatériaux consiste, en amont de l'application, à comprendre les différents processus intervenant dans la synthèse. Cette approche permet de définir les conditions de synthèse qui conduiront au contrôle de leur cristallinité, composition et morphologie. Ce manuscrit d'habilitation à diriger des recherches présente mes travaux et projet de recherche sur "Élaboration raisonnée de nanomatériaux mono- et bimétalliques". Il s'articule autour de quatre chapitres qui apportent des éléments de compréhension quant au contrôle des différents paramètres requis pour l'élaboration de systèmes valorisables en catalyse et/ ou dans le stockage d'information. Cela concerne d'une part la synthèse contrôlée (cristallinité, morphologie, composition) de nanoobjets mono- et/ou bimétalliques et d'autre part le contrôle de leur organisation en des réseaux au sein desquels il est possible de moduler les interactions.

Exporter la référence : tel-04000632v1 (2019)
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Y. Fan, A. Girard, M. Waals, C. Salzemann, A. Courty

Ag(at)Pt Core–Shell Nanoparticles for Plasmonic Catalysis

Bimetallic nanocatalysts (NCs) composed of two metal elements are a promising way to achieve high catalytic performance, based on so-called synergistic effects. In this context, we have designed bimetallic core-shell nanoparticles (NPs) combining a plasmonic metal Ag as core and a catalytic metal Pt as shell. Ag(at)Pt core-shell NPs were synthesized via a seed-mediated growth process allowing fine control of the Ag core size and Pt shell thickness. In a first step, Ag seeds (8-13nm) with a narrow size distribution (

Exporter la référence : hal-04004084v1 2023
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I. Fikri, M. El Amraoui, M. Haddad, A. Saleh Ettahiri, C. Falguères, L. Bellot-Gurlet and al.

Raman and ATR-FTIR analyses of medieval wall paintings from al-Qarawiyyin in Fez (Morocco)

A multi-analytical study has been undertaken to characterise wall paintings from the al-Qarawiyyin university in Fez, dating back to the 9th century and still in activity, with the aim of identifying the pigments used and going back to the painting techniques adopted by the Moroccan craftsmen of the time. The investigation crossed Raman and ATR-FTIR structural analyses along with XRF elemental ones, as well as colorimetric measurements...

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C. Mouraux, F. Delarue, J. Bardin, T.T. Nguyen Tu, L. Bellot-Gurlet, C. Paris, S. Coubray and A. Dufraise

Assessing the carbonisation temperatures recorded by ancient charcoals...

Ancient charcoal fragments, produced by the use of wood as fuel in archaeological contexts or during natural or anthropic forest fires, persist in soil and sediments over centuries to millennia. They thus offer a unique window to reconstruct past climate, especially palaeo-precipitation regimes thanks to their stable carbon isotope composition. However, the initial δ13C of wood is slightly modified as a function of the carbonisation temperature...

Exporter la référence : DOI: s41598-022-17836-2 (2022)
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Jacques Burlot, Yona S. Waksman, Ludovic Bellot-Gurlet, Gulsu Simsek Franci

The glaze production technology of an early Ottoman pottery (mid-14th(?)-16th century): The case of "Miletus Ware"

"Miletus Ware", considered as one of the first wares produced by Ottoman potters in western Anatolia, featured new typological and stylistic characteristics that suggested the introduction of new recipes and the use of new materials in the local repertoire. This study, conducted on archaeological samples of Miletus Ware from eight sites in Turkey and in the Crimea, supports this view. It focuses on the decoration techniques, through the analyses of glazes and underglaze decorations using SEM-EDS and Raman spectroscopy. The results show that, compared to what Byzantine and Beylik potters previously produced in western Anatolia, there were two main innovations in the Miletus Ware glaze production technology. First, its glaze recipe included new sodium-based fluxes. Second, some underglaze decorations as represented by the black and dark-blue-colored ones - obtained respectively through the use of pigments featuring magnesiochromite and cobalt - were produced with materials that had not been used in the region before.

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S. Groni, C. Fave, B. Schollhorn, L. Chapus, P. Aubertin, T. Touzalin, I.T. Lucas, S. Joiret, A. Courty, E. Maisonhaute

Long range self-organisations of small metallic nanocrystals for SERS detection of electrochemical reactions

Gold electrodes were modified by silver and gold nanocrystals (NCs) that self-organize onto the surface. Their optical properties were explored by measuring electro-reflectance spectra as a function of electrode potential. Below their oxidation potential, no shift of the reflectance maximum was observed for Ag NCs. This can be explained by a low interfacial capacitance resulting from the impossibility for the electrolyte to penetrate into the hydrophobic layer created by the NCs dodecanethiol ligands. Conversely, a non-monotonous evolution was observed with the electrode potential for oleylamine capped Au NCs.

Exporter la référence : DOI:10.1016/j.jelechem.2020.114322
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N. Dridi, L. Manceron, F. Hmida, M. Rotger, H. Aroui

Line intensity parameters in the nu(3) and 2 nu(3)-nu(3) bands of methyl chloride in the 13 mu m region

We performed the systematic measurements of line intensities of ro-vibrational absorption transitions of the nu(3) and 2 nu(3)-nu(3) parallel bands of (CH3Cl)-C-12-Cl-35 and (CH3Cl)-C-12-Cl-37 isotopes. The spectra were recorded in the spectral region between 650 and 800 cm(-1) with a high-resolution Fourier transform spectrometer. A mono-spectrum fitting technique was used to fit a series of seven spectra at pressures of CH3Cl ranging from 1.02 to 10.24 mbar to retrieve line intensities of 2385 transitions of the two isotopic species. The measured line intensities are discussed in relation to rotational quantum numbers, and used to derive the square of the transition dipole moments for each line. The analysis of these moments allows us to derive a consistent set of line intensity parameters, such as vibrational transition moments, band intensities as well as Herman-Wallis coefficients for both bands...

Exporter la référence : DOI:10.1016/j.jqsrt.2020.107036 (2020)
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