Search

Your search keyword '"Julie AUFORT"' showing total 6 results
Start Over Author "Julie AUFORT" Topic chemistry
6 results on '"Julie AUFORT"'

1. Simulating the binding of key organic functional groups to aqueous calcium carbonate species

Author

Alicia Schuitemaker, Paolo Raiteri, Julie Aufort, Julian D. Gale, Raffaella Demichelis, and Katarzyna B. Koziara

Subjects
Mineral, Aqueous solution, 010304 chemical physics, Ion pairing, Solvation, General Physics and Astronomy, 010402 general chemistry, 01 natural sciences, 0104 chemical sciences, Organic molecules, chemistry.chemical_compound, Calcium carbonate, chemistry, Computational chemistry, 0103 physical sciences, Ammonium, Carboxylate, Physical and Theoretical Chemistry
Abstract

The interaction of organic molecules with mineral systems is relevant to a wide variety of scientific problems both in the environment and minerals processing. In this study, the coordination of small organics that contain the two most relevant functional groups for biomineralisation of calcium carbonate, namely carboxylate and ammonium, with the corresponding mineral ions are examined in aqueous solution. Specifically, two force fields have been examined based on rigid-ion or polarisable models, with the latter being within the AMOEBA formalism. Here the parameters for the rigid-ion model are determined to target the accurate reproduction of the hydration structure and solvation thermodynamics, while both force fields are designed to be compatible with the corresponding recently published models for aqueous calcium carbonate. The application of these force fields to ion pairing in aqueous solution is studied in order to quantitatively determine the extent of association.

Published
2021
Full Text
View/download PDF

2. Magnesium Impurities Decide the Structure of Calcium Carbonate Hemihydrate

Author

Julie Aufort, Raffaella Demichelis, Institut de minéralogie, de physique des matériaux et de cosmochimie (IMPMC), Muséum national d'Histoire naturelle (MNHN)-Institut de recherche pour le développement [IRD] : UR206-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Curtin Institute for Computation (CIC), Curtin University [Perth], and Planning and Transport Research Centre (PATREC)-Planning and Transport Research Centre (PATREC)

Subjects
Materials science, 010405 organic chemistry, Magnesium, Hemihydrate, chemistry.chemical_element, General Chemistry, Orientation (graph theory), 010402 general chemistry, Condensed Matter Physics, 01 natural sciences, 0104 chemical sciences, chemistry.chemical_compound, Calcium carbonate, chemistry, Chemical engineering, Impurity, Theoretical methods, [CHIM]Chemical Sciences, General Materials Science
Abstract

The new and recently detected hydromorph of calcium carbonate, CaCO3 center dot 1/2H(2)O hemihydrate, has been analyzed via both first-principles and classical theoretical methods. The orientation of the water molecules, that remained unclear in the experiment, has been determined. A structure with symmetry higher than that originally proposed results from geometry optimization (Pbcn, space group number 60) of the pure phase. The introduction of magnesium impurities causes a distortion in the unit cell, which assumes the monoclinic arrangement (P2(1)/c) originally proposed. This is consistent with the magnesium-rich experimental conditions.

Published
2020
Full Text
View/download PDF

3. Atomic scale transformation of bone in controlled aqueous alteration experiments

Author

Cristina Coelho-Diogo, Nathalie Labourdette, Christophe Lécuyer, Romain Amiot, Christel Gervais, Olivier Beyssac, Julie Aufort, Loïc Ségalen, Etienne Balan, Benoit Baptiste, Institut de minéralogie, de physique des matériaux et de cosmochimie (IMPMC), Muséum national d'Histoire naturelle (MNHN)-Institut de recherche pour le développement [IRD] : UR206-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Spectroscopie, Modélisation, Interfaces pour L'Environnement et la Santé (LCMCP-SMiLES), Laboratoire de Chimie de la Matière Condensée de Paris (LCMCP), Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Institut des Sciences de la Terre de Paris (iSTeP), Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU)-Institut national des sciences de l'Univers (INSU - CNRS), Institut des matériaux de Paris-Centre (IMPC), Ecole Nationale Supérieure de Chimie de Paris - Chimie ParisTech-PSL (ENSCP), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Ecole Superieure de Physique et de Chimie Industrielles de la Ville de Paris (ESPCI Paris), Université Paris sciences et lettres (PSL)-Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Géologie de Lyon - Terre, Planètes, Environnement [Lyon] (LGL-TPE), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-École normale supérieure - Lyon (ENS Lyon), PaleoEnvironnements et PaleobioSphere (PEPS), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Collège de France (CdF)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Collège de France (CdF)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Ecole Nationale Supérieure de Chimie de Paris- Chimie ParisTech-PSL (ENSCP)-ESPCI ParisTech-Sorbonne Université (SU), Université de Lyon-Université de Lyon, Laboratoire de Géologie de Lyon - Terre, Planètes, Environnement (LGL-TPE), École normale supérieure de Lyon (ENS de Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut national des sciences de l'Univers (INSU - CNRS)-Université Jean Monnet - Saint-Étienne (UJM)-Centre National de la Recherche Scientifique (CNRS), École normale supérieure - Lyon (ENS Lyon)-Université Claude Bernard Lyon 1 (UCBL), Institut national des sciences de l'Univers (INSU - CNRS)-Université Claude Bernard Lyon 1 (UCBL), and Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS)

Subjects
010506 paleontology, Aqueous solution, Fluorapatite, Inorganic chemistry, Paleontology, Hydroxylapatite, 010502 geochemistry & geophysics, Oceanography, 01 natural sciences, Apatite, chemistry.chemical_compound, Crystallinity, chemistry, [SDU]Sciences of the Universe [physics], [SDU.STU.GC]Sciences of the Universe [physics]/Earth Sciences/Geochemistry, visual_art, visual_art.visual_art_medium, Carbonate, Dissolution, Fluoride, Ecology, Evolution, Behavior and Systematics, Geology, ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences, Earth-Surface Processes
Abstract

International audience; The chemical and isotopic compositions of biogenic apatite are important geochemical markers, which can suffer modifications during fossilisation. Compared with modern ones, fossil apatites generally exhibit variations in carbonate content, enrichment in fluorine, incorporation of trace elements and an increase in crystallinity parameters. Detailed understanding of these transformations induced by fossilisation should help assess the preservation of geochemical records in apatites. In this contribution, we investigate the transformation of modern bone altered under controlled conditions. Modern bone samples were soaked in aqueous solutions of neutral to alkaline pH (9–10) for one and three weeks at various temperatures (20 and 70 °C) and experiments were duplicated in fluorine-free and in 10−2 M NaF solutions. Bone transformation was monitored through the modifications of chemical (F, Ca, P) and isotopic (δ13C, δ18Oc, δ18Op) composition as well as using vibrational (ATR-FTIR, Raman) and solid-state (1H, 13C, 19F) NMR spectroscopies. The observed modifications sustain a transformation mechanism through partial dissolution of biogenic apatite and precipitation of secondary apatite. This transformation occurs irrespective of the presence or absence of fluorine and leads to the formation of carbonate-bearing fluorapatite or carbonate-bearing hydroxylapatite, respectively. The fraction of secondary apatite seems to be limited to ~60%, suggesting that its formation has a protecting role against further dissolution of the primary apatite. The observation of clumped (CO32−, F−) defects in the structural B-site of some samples as well as perturbation of the isotopic compositions attest to carbonate incorporation in the secondary apatite. Although the incorporation of fluoride ions can serve as a probe revealing dissolution-recrystallization of bone, the present study also underlines the difficulty to systematically relate mineralogical transformations to an open-system behaviour in bioapatite.

Published
2019
Full Text
View/download PDF

4. Modeling the attenuated total reflectance infrared (ATR-FTIR) spectrum of apatite

Author

Etienne Balan, Christian Brouder, Loïc Ségalen, Julie Aufort, Christel Gervais, Institut de minéralogie, de physique des matériaux et de cosmochimie (IMPMC), Muséum national d'Histoire naturelle (MNHN)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut de recherche pour le développement [IRD] : UR206-Centre National de la Recherche Scientifique (CNRS), Biominéralisations et environnements sédimentaires (BES), Institut des Sciences de la Terre de Paris (iSTeP), Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS), Spectroscopie, Modélisation, Interfaces pour L'Environnement et la Santé (SMiLES), Laboratoire de Chimie de la Matière Condensée de Paris (LCMCP), Université Pierre et Marie Curie - Paris 6 (UPMC)-Collège de France (CdF (institution))-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Collège de France (CdF (institution))-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Labex Matisse, ANR-11-IDEX-0004,SUPER,Sorbonne Universités à Paris pour l'Enseignement et la Recherche(2011), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut de recherche pour le développement [IRD] : UR206-Muséum national d'Histoire naturelle (MNHN)-Centre National de la Recherche Scientifique (CNRS), and Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS)-Collège de France (CdF (institution))-Institut de Chimie du CNRS (INC)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS)-Collège de France (CdF (institution))-Institut de Chimie du CNRS (INC)

Subjects
Infrared, Analytical chemistry, Physics::Optics, Infrared spectroscopy, Effective medium, Bruggeman model, 02 engineering and technology, 010502 geochemistry & geophysics, 01 natural sciences, Apatite, Geochemistry and Petrology, General Materials Science, Fourier transform infrared spectroscopy, 0105 earth and related environmental sciences, [PHYS]Physics [physics], Chemistry, Fluorapatite, [CHIM.MATE]Chemical Sciences/Material chemistry, Fresnel equations, 021001 nanoscience & nanotechnology, Wavelength, visual_art, Attenuated total reflection, visual_art.visual_art_medium, Attenuated total reflectance, 0210 nano-technology, ATR-FTIR, [SDU.STU.MI]Sciences of the Universe [physics]/Earth Sciences/Mineralogy
Abstract

International audience; Attenuated total reflectance (ATR) infrared spectra were measured on a synthetic and a natural fluorapatite sample. A modeling approach based on the computation of the Fresnel reflection coefficient between the ATR crystal and the powder sample was used to analyze the line shape of the spectra. The dielectric properties of the samples were related to those of pure fluorapatite using an effective medium approach, based on Maxwell–Garnett and Bruggeman models. The Bruggeman effective medium model leads to a very good agreement with the experimental data recorded on the synthetic fluorapatite sample. The poorer agreement observed on the natural sample suggests a more significant heterogeneity of the sample at a characteristic length scale larger than the mid-infrared characteristic wavelength, i.e., about 10 micrometers. The results demonstrate the prominent role of macroscopic electrostatic effects over fine details of the microscopic structure in determining the line shape of strong ATR bands.

Published
2016
Full Text
View/download PDF

5. Line-broadening and anharmonic effects in the attenuated total reflectance infrared spectra of calcite

Author

Etienne Balan, Julie Aufort, Michele Lazzeri, Christian Brouder, Giuseppe D. Saldi, Institut de minéralogie, de physique des matériaux et de cosmochimie (IMPMC), Muséum national d'Histoire naturelle (MNHN)-Institut de recherche pour le développement [IRD] : UR206-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Géosciences Environnement Toulouse (GET), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD), Cluster of Excellence MATISSE led by Sorbonne UniversitésCARBORIC (ANR-13-BS06-0013-06), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), and Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS)

Subjects
Calcite, Materials science, Anharmonicity, Analytical chemistry, Infrared spectroscopy, 02 engineering and technology, multi-phonon, 021001 nanoscience & nanotechnology, 01 natural sciences, effective medium, chemistry.chemical_compound, ATR, chemistry, Geochemistry and Petrology, Attenuated total reflection, 0103 physical sciences, [PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], 010306 general physics, 0210 nano-technology, infrared spectroscopy, calcite, Line (formation), [SDU.STU.MI]Sciences of the Universe [physics]/Earth Sciences/Mineralogy
Abstract

International audience; The attenuated total reflectance (ATR) spectra of two calcite samples have been measured using Ge and diamond internal reflection elements. One of the samples was obtained by precipitation from solution and displays sub-micrometer sized particles. The second sample was obtained by grinding a single-crystal of calcite (''Iceland spar'' variety). Theoretical spectra were obtained by computing the reflection coefficient of the interface between the ATR internal reflection element and a homogeneous effective medium representing the powder sample. The dielectric properties of the effective medium have been determined from those of bulk calcite using the Bruggeman approach which is adequate for standard powders with intermediate fractions of solid and empty porosity. Although this modeling approach provides a quantitative interpretation of the broadening of strong absorption bands in the calcite ATR spectra, it fails to reproduce the apparent splitting of the strong nu3 CO3 band. This problem was solved by combining the electrostatic modeling approach with a semi-quantum model of the dielectric tensor of bulk calcite, which allows for a frequency-dependent damping of the nu3 CO3 excitation. The frequency-dependence is ascribed to a multiphonon-related resonance in the nu3 CO3 phonon self-energy at a frequency close to its transverse optical frequency. The combination of approaches exposed in the present study makes it possible to discriminate among physically different processes affecting the powder infrared spectra of calcite, some being related to the long-range nature of electrostatic interactions in polar materials and others being related to atomic-scale anharmonic interactions between vibrational modes.

Published
2019
Full Text
View/download PDF

6. Infrared spectroscopic study of sulfate-bearing calcite from deep-sea bamboo coral

Author

Sophie Pouillé, Julie Aufort, Marc Blanchard, Michele Lazzeri, D. Blamart, Etienne Balan, Marie Dabos, Claire Rollion-Bard, Institut de minéralogie, de physique des matériaux et de cosmochimie (IMPMC), Muséum national d'Histoire naturelle (MNHN)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut de recherche pour le développement [IRD] : UR206-Centre National de la Recherche Scientifique (CNRS), Laboratoire des Sciences du Climat et de l'Environnement [Gif-sur-Yvette] (LSCE), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Paléocéanographie (PALEOCEAN), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut de recherche pour le développement [IRD] : UR206-Muséum national d'Histoire naturelle (MNHN)-Centre National de la Recherche Scientifique (CNRS), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), and Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)

Subjects
Calcite, 010504 meteorology & atmospheric sciences, biology, Infrared, Analytical chemistry, Diamond, Infrared spectroscopy, Mineralogy, engineering.material, 010502 geochemistry & geophysics, biology.organism_classification, 01 natural sciences, Thermal expansion, chemistry.chemical_compound, Bamboo coral, chemistry, Geochemistry and Petrology, Attenuated total reflection, engineering, Sulfate, ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences, [SDU.STU.MI]Sciences of the Universe [physics]/Earth Sciences/Mineralogy
Abstract

The powder infrared spectra of a sulfate-bearing calcitic coral sample are recorded at room temperature in attenuated total reflectance (ATR) geometry and at low temperature in transmission geometry. The comparison of ATR spectra recorded with diamond or Ge crystal confirms that the width and the shape of the prominent absorption bands, related to CO 3 groups, are dominantly affected by macroscopic electrostatic interactions. In contrast, the temperature-dependence of the position and width of weak and narrow absorption bands, related to CO 3 or SO 4 groups, can be interpreted in terms of thermal expansion, anharmonic coupling, and local strain fluctuations. The three SO 4 stretching bands display a contrasted thermal behavior, the frequency of one of them increasing with temperature. Based on first-principles calculation, this unusual temperature dependence is traced back to the anisotropy of calcite thermal expansion. These results sustain the previously proposed atomic-scale model of sulfate in calcite and attest to a dominantly structural nature of sulfate in the investigated sample. Accordingly, structurally substituted sulfur in deep-sea calcitic bamboo coral could be used as proxy of seawater sulfate.

Published
2017
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results