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Dive into the research topics where Hélène Gailhanou is active.

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Featured researches published by Hélène Gailhanou.


American Journal of Science | 2015

A generalized model for predicting the thermodynamic properties of clay minerals

Philippe Blanc; Philippe Vieillard; Hélène Gailhanou; Stéphane Gaboreau; Eric C. Gaucher; Claire I. Fialips; Benoît Madé; Eric Giffaut

A set of models for estimating the enthalpy of formation, the entropy, the heat capacity and the volume of dehydrated phyllosilicates is presented. The model for entropy and heat capacity estimation is essentially based on a method of decomposition into polyhedral units, similar to that published by Holland (1989). The model for predicting the enthalpy of formation is based on the electronegativity scale, as previously developed by Vieillard (1994a, 1994b). For the sake of consistency, the models are parameterized using the same critical selection of thermodynamic properties from the literature. This includes a set of direct measurements especially dedicated to clay minerals that had not been taken into account in previous calculation methods. The accuracy of the predictions is tested for each property. The verification tests are also carried out for minerals that include different chemical elements than the phases used to derive the model constants, especially lithium-bearing micas. Verification tests also concern the Gibbs energy function that combines contributions from both models. Finally, the models are used in order to propose a complete thermodynamic database for clay mineral end-members. The consistency of the stability domains calculated on the basis of these thermodynamic properties is investigated by drawing relevant predominance diagrams for some chemical systems of interest. The models proposed represent a significant improvement with respect to previous works as regards the global accuracy of the estimates and because the developments were realized and tested using the same set of minerals, whose properties had been collected through a critical selection of the literature.


American Mineralogist | 2013

Thermodynamic properties of saponite, nontronite, and vermiculite derived from calorimetric measurements

Hélène Gailhanou; Philippe Blanc; Jacques Rogez; G. Mikaelian; Katsuya Horiuchi; Yasuhisa Yamamura; Kazuya Saito; Hitoshi Kawaji; Fabienne Warmont; Jean-Marc Greneche; Philippe Vieillard; Claire I. Fialips; Eric Giffaut; Eric C. Gaucher

Abstract The stability of clay minerals is an important factor in assessing the durability of containment barriers for deep waste storage. In that context, the complete thermodynamic data set of three 2:1 ferro-magnesian clay minerals have been determined at 1 bar and from 2 to 520 K, using calorimetric methods. The studied clay samples were, respectively, the Na-saturated saponite Sap-Ca-1, Na0.394 K0.021Ca0.038(Si3.569Al0.397Fe3+0.034)(Mg2.948Fe2+0.021Mn0.001)O10(OH)2, the Ca-saturated nontronite NAu-1, Ca0.247K0.020(Si3.458Al0.542)(Mg0.066Fe3+1.688Al0.268Ti0.007)O10(OH)2, and the Ca-saturated Santa Olalla vermiculite, Ca0.445(Si2.778Al1.222)(Al0.192Mg2.468Fe3+0.226Fe2+0.028Ti0.018Mn0.007)O10(OH)2. The standard enthalpies of formation were obtained by solution-reaction calorimetry at 298.15 K. The heat capacities were measured between 2 and 520 K, using low-temperature adiabatic calorimetry, heat-pulse calorimetry, and differential scanning calorimetry. The standard entropies and the Gibbs free energies of formation at 298.15 K have been calculated from these values. Finally, the equilibrium constants at 298.15 K have been determined. A comparison between these experimental data and estimated values obtained from prediction models available in the literature enabled the most usual calculation methods available to date to be assessed for each thermodynamic property.


Applied Geochemistry | 2014

Andra thermodynamic database for performance assessment: ThermoChimie

Eric Giffaut; Mireia Grivé; Philippe Blanc; Philippe Vieillard; Elisenda Colàs; Hélène Gailhanou; Stéphane Gaboreau; Nicolas C.M. Marty; Benoît Madé; Lara Duro


Geotextiles and Geomembranes | 2009

Performance-based indicators for controlling geosynthetic clay liners in landfill applications

Dominique Guyonnet; Nathalie Touze-Foltz; Véronique Norotte; Catherine Pothier; Gérard Didier; Hélène Gailhanou; Philippe Blanc; Fabienne Warmont


Soil Science Society of America Journal | 2009

Cation exchange selectivity coefficient values on smectite and mixed-layer illite/smectite minerals.

Christophe Tournassat; Hélène Gailhanou; Catherine Crouzet; Gilles Braibant; Anne Gautier; Eric C. Gaucher


Geochimica et Cosmochimica Acta | 2007

Thermodynamic properties of anhydrous smectite MX-80, illite IMt-2 and mixed-layer illite-smectite ISCz-1 as determined by calorimetric methods. Part I Heat capacities, heat contents and entropies

Hélène Gailhanou; J.C. van Miltenburg; J. Rogez; Juan Olives; Marc Amouric; Eric C. Gaucher; Philippe Blanc


Geochimica et Cosmochimica Acta | 2012

Thermodynamic properties of illite, smectite and beidellite by calorimetric methods: Enthalpies of formation, heat capacities, entropies and Gibbs free energies of formation

Hélène Gailhanou; Philippe Blanc; Jacques Rogez; G. Mikaelian; Hitoshi Kawaji; Juan Olives; Marc Amouric; Renaud Denoyel; S. Bourrelly; Valérie Montouillout; Philippe Vieillard; Claire I. Fialips; Nicolas Michau; Eric C. Gaucher


Geochimica et Cosmochimica Acta | 2007

Two cation exchange models for direct and inverse modelling of solution major cation composition in equilibrium with illite surfaces

Christophe Tournassat; Hélène Gailhanou; Catherine Crouzet; Gilles Braibant; Anne Gautier; Arnault Lassin; Philippe Blanc; Eric C. Gaucher


Geochimica et Cosmochimica Acta | 2009

Thermodynamic properties of chlorite CCa-2. Heat capacities, heat contents and entropies

Hélène Gailhanou; J. Rogez; J.C. van Miltenburg; A.C.G. van Genderen; Jean Marc Greneche; C. Gilles; D. Jalabert; Nicolas Michau; Eric C. Gaucher; Philippe Blanc


Geochimica et Cosmochimica Acta | 2011

Hydration thermodynamics of the SWy-1 montmorillonite saturated with alkali and alkaline-earth cations: A predictive model

Philippe Vieillard; Philippe Blanc; Claire I. Fialips; Hélène Gailhanou; Stéphane Gaboreau

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Stéphane Gaboreau

Centre national de la recherche scientifique

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Philippe Blanc

Pierre-and-Marie-Curie University

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Christophe Tournassat

Lawrence Berkeley National Laboratory

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Jacques Rogez

Aix-Marseille University

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Renaud Denoyel

Aix-Marseille University

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Fabienne Warmont

Centre national de la recherche scientifique

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Marc Amouric

Centre national de la recherche scientifique

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Sylvain Grangeon

Centre national de la recherche scientifique

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