Search

Your search keyword '"Université de Limoges (UNILIM)-Institut des Procédés Appliqués aux Matériaux (IPAM)"' showing total 77 results
Start Over Author "Université de Limoges (UNILIM)-Institut des Procédés Appliqués aux Matériaux (IPAM)" Publisher elsevier bv
77 results on '"Université de Limoges (UNILIM)-Institut des Procédés Appliqués aux Matériaux (IPAM)"'

1. Comparative study of the various methods of preparation of silicate solution and its effect on the geopolymerization reaction

Author

Sylvie Rossignol, N. Essaidi, Laurent Ulmet, L. Laou, Sylvie Yotte, Science des Procédés Céramiques et de Traitements de Surface (SPCTS), Université de Limoges (UNILIM)-Ecole Nationale Supérieure de Céramique Industrielle (ENSCI)-Institut des Procédés Appliqués aux Matériaux (IPAM), Université de Limoges (UNILIM)-Université de Limoges (UNILIM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Groupe d'Etudes des Matériaux Hétérogènes (GEMH), Université de Limoges (UNILIM)-Institut des Procédés Appliqués aux Matériaux (IPAM), Université de Limoges (UNILIM)-Université de Limoges (UNILIM), Axe 3 : organisation structurale multiéchelle des matériaux (SPCTS-AXE3), Université de Limoges (UNILIM)-Université de Limoges (UNILIM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Limoges (UNILIM)-Ecole Nationale Supérieure de Céramique Industrielle (ENSCI)-Institut des Procédés Appliqués aux Matériaux (IPAM), Institut des Procédés Appliqués aux Matériaux (IPAM), Université de Limoges (UNILIM)-Université de Limoges (UNILIM)-Ecole Nationale Supérieure de Céramique Industrielle (ENSCI)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Limoges (UNILIM), and Université de Limoges (UNILIM)-Université de Limoges (UNILIM)-Ecole Nationale Supérieure de Céramique Industrielle (ENSCI)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Limoges (UNILIM)-Institut des Procédés Appliqués aux Matériaux (IPAM)

Subjects
Metakaolin reactivity, Materials science, 0211 other engineering and technologies, General Physics and Astronomy, 02 engineering and technology, [CHIM.INOR]Chemical Sciences/Inorganic chemistry, Physics and Astronomy(all), Alkaline solution, chemistry.chemical_compound, Aluminosilicate, Bricks, 021105 building & construction, Binders, Fourier transform infrared spectroscopy, Brick, Depolymerization, Silicate powder, [CHIM.MATE]Chemical Sciences/Material chemistry, 021001 nanoscience & nanotechnology, Silicate, lcsh:QC1-999, Characterization (materials science), Geopolymer, [CHIM.POLY]Chemical Sciences/Polymers, Polymerization, Chemical engineering, chemistry, 0210 nano-technology, lcsh:Physics
Abstract

This paper is based on the characterization of synthesized geopolymer binders based on either powder or solution silicate, and the amount of water contained in synthesized binders is determined to evaluate their possibility to coat a brick. The structural evolution of the formed geopolymers was investigated using FTIR spectroscopy. The mechanical properties were evaluated using compression tests. The structural evolution ensured that the solutions prepared from silicate powder or liquid had different degrees of polymerization, which modified the polycondensation reaction of the mixture. Nevertheless, the use of aluminosilicate solutions based on powder or liquid display similar behavior in a polycondensation reaction. The obtained materials show good mechanical properties, and it is possible to deposit this binder on the brick depending on the water content. Keywords: Silicate powder, Bricks, Alkaline solution, Binders, Depolymerization, Metakaolin reactivity

Published
2016
Full Text
View/download PDF

2. Formulation of new materials based on geopolymer binders and different road aggregates

Author

Fatima Allou, Joseph Absi, Sylvie Rossignol, Christophe Petit, Nadine Tenn, Axe 3 : organisation structurale multiéchelle des matériaux (SPCTS-AXE3), Science des Procédés Céramiques et de Traitements de Surface (SPCTS), Institut des Procédés Appliqués aux Matériaux (IPAM), Université de Limoges (UNILIM)-Université de Limoges (UNILIM)-Ecole Nationale Supérieure de Céramique Industrielle (ENSCI)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Limoges (UNILIM)-Institut des Procédés Appliqués aux Matériaux (IPAM), Université de Limoges (UNILIM)-Université de Limoges (UNILIM)-Ecole Nationale Supérieure de Céramique Industrielle (ENSCI)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Limoges (UNILIM), Groupe d'Etudes des Matériaux Hétérogènes (GEMH), Université de Limoges (UNILIM)-Institut des Procédés Appliqués aux Matériaux (IPAM), and Université de Limoges (UNILIM)-Université de Limoges (UNILIM)

Subjects
chemistry.chemical_classification, Materials science, Base (chemistry), Road construction, Process Chemistry and Technology, Sodium, Potassium, 0211 other engineering and technologies, New materials, chemistry.chemical_element, 020101 civil engineering, [CHIM.MATE]Chemical Sciences/Material chemistry, 02 engineering and technology, 0201 civil engineering, Surfaces, Coatings and Films, Electronic, Optical and Magnetic Materials, Diorite, Geopolymer, chemistry, Asphalt, 021105 building & construction, Materials Chemistry, Ceramics and Composites, Composite material, ComputingMilieux_MISCELLANEOUS
Abstract

The study of bitumen substitution in the field of road construction is necessary to overcome the effects of limited oil resources and economic problems. The elaboration of new materials based on geopolymer binders and aggregates was investigated in this work. Two series of formulations of geopolymer binders based on sodium or potassium were prepared with the incorporation of granite or diorite. The formulation of these binder was investigated by the study of (i) the effect of the nature of the alkaline solution by modify the pH value with base and (ii) the mass percentage of the incorporated aggregates. The time evolution study shows different aspects of the synthesized materials, which depend essentially on the composition of the activating solutions and the nature of the alkaline solutions. The formulations using these ratios (Si/Na=1.55; Si/K=1.94 and 2.96) appear the best. Moreover, it was evidenced that materials based on the potassium alkaline solution present a consolidated aspect faster than the materials based on the sodium alkaline solution. Additionally, it is possible to incorporate diorite or granite until 60 w% with some formulations. These various formulations are promising to be use not as a substitute of bitumen but in addition between bitumen and ground.

Published
2015

3. Effect of the addition of ammonium molybdate on metakaolin-based geopolymer formation: Shrinkage and crystallization

Author

M. Colas, Laeticia Vidal, Emmanuel Joussein, Joseph Absi, Sylvie Rossignol, Science des Procédés Céramiques et de Traitements de Surface (SPCTS), Institut des Procédés Appliqués aux Matériaux (IPAM), Université de Limoges (UNILIM)-Université de Limoges (UNILIM)-Ecole Nationale Supérieure de Céramique Industrielle (ENSCI)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Limoges (UNILIM), Groupement de Recherche Eau, Sol, Environnement (GRESE), Université de Limoges (UNILIM), Axe 3 : organisation structurale multiéchelle des matériaux (SPCTS-AXE3), Université de Limoges (UNILIM)-Université de Limoges (UNILIM)-Ecole Nationale Supérieure de Céramique Industrielle (ENSCI)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Limoges (UNILIM)-Institut des Procédés Appliqués aux Matériaux (IPAM), Groupe d'Etudes des Matériaux Hétérogènes (GEMH), Université de Limoges (UNILIM)-Institut des Procédés Appliqués aux Matériaux (IPAM), and Université de Limoges (UNILIM)-Université de Limoges (UNILIM)

Subjects
Ammonium molybdate, General Chemical Engineering, Inorganic chemistry, chemistry.chemical_element, [CHIM.MATE]Chemical Sciences/Material chemistry, Microstructure, law.invention, Geopolymer, symbols.namesake, chemistry, Chemical engineering, law, Molybdenum, symbols, Crystallization, Raman spectroscopy, ComputingMilieux_MISCELLANEOUS, Metakaolin, Shrinkage
Abstract

This paper focuses on the influence of the addition of ammonium molybdate to geopolymer mixtures to better understand the formation of geopolymer structural networks and the effect of Mo-based additive on the thermal behavior of material. Several geopolymers were synthesized between two metakaolins and various amounts of ammonium molybdate. The microstructure of samples was determined by SEM, the structural evolution (depending on the amount of molybdenum added) was investigated using Raman spectroscopy and XRD analyses, and the temperature behaviors of materials by DTA–TGA and dilatometric analyses. The results showed that (i) both metakaolins react differently in the presence of ammonium molybdate, (ii) molybdenum induces decrease of shrinkage value at high temperatures, and (iii) the crystallization seems to be favored with ammonium molybdate. This work shows that ammonium molybdate controls polycondensation reactions highlighting the modifier or former role played by the molybdenum atoms depending on the amount of ammonium molybdate added.

Published
2015

4. Bulk composition and microstructure dependence of effective thermal conductivity of porous inorganic polymer cements

Author

Mc Bignozzi, Sylvie Rossignol, David S. Smith, Benoît Nait-Ali, Ellie Kamseu, Cristina Leonelli, E. Kamseu, B. Nait-Ali, M.C. Bignozzi, C. Leonelli, S. Rossignol, D.S. Smith, Groupe d'Etudes des Matériaux Hétérogènes (GEMH), Université de Limoges (UNILIM)-Institut des Procédés Appliqués aux Matériaux (IPAM), Université de Limoges (UNILIM)-Université de Limoges (UNILIM), Axe 3 : organisation structurale multiéchelle des matériaux (SPCTS-AXE3), Science des Procédés Céramiques et de Traitements de Surface (SPCTS), Institut des Procédés Appliqués aux Matériaux (IPAM), Université de Limoges (UNILIM)-Université de Limoges (UNILIM)-Ecole Nationale Supérieure de Céramique Industrielle (ENSCI)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Limoges (UNILIM)-Institut des Procédés Appliqués aux Matériaux (IPAM), Université de Limoges (UNILIM)-Université de Limoges (UNILIM)-Ecole Nationale Supérieure de Céramique Industrielle (ENSCI)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Limoges (UNILIM), Università degli Studi di Modena e Reggio Emilia (UNIMORE), Alma Mater Studiorum Università di Bologna [Bologna] (UNIBO), and Rossignol, Sylvie

Subjects
Materials Chemistry2506 Metals and Alloys, Materials science, Microstructure-final, 0211 other engineering and technologies, 02 engineering and technology, Matrix (geology), Thermal conductivity, Thermal insulation, Inorganic polymer cements, EFFECTIVE THERMAL CONDUCTIVITY, 021105 building & construction, Homogeneity (physics), Materials Chemistry, Composites, Porosity, Ceramics and Composites, Composite material, Chemical composition, ANALYTICAL MODELS, [CHIM.MATE] Chemical Sciences/Material chemistry, Inorganic polymer, POROUS GEOPOLYMERS, business.industry, POROSITY, [CHIM.MATE]Chemical Sciences/Material chemistry, 021001 nanoscience & nanotechnology, Microstructure, PORE SIZE, 0210 nano-technology, business
Abstract

International audience; Experimental results and theoretical models are used to assess the effective thermal conductivity of porous inorganic polymer cements, often indicated as geopolymers, with porosity between 30 and 70. vol.%. It is shown that the bulk chemical composition affects the microstructure (grains size, pores size, spatial arrangement of pores, homogeneity, micro cracks, bleeding channels) with consequently the heat flow behaviour through the porous matrix. In particular, introduction of controlled fine pores in a homogeneous matrix of inorganic polymer cements results in an increase of pore volume and improvement of the thermal insulation. The variation of the effective thermal conductivity with the total porosity was found to be consistent with analytical models described by Maxwell-Eucken and Landauer.

Published
2012

5. Microstructural and electrical characterization of bulk YBa2Cu3O7−δ ceramics

Author

David S. Smith, A. Khalfi, Jean Pierre Bonnet, G. Trolliard, M.F. Khalfi, S. Suasmoro, Groupe d'Etudes des Matériaux Hétérogènes (GEMH), Université de Limoges (UNILIM)-Institut des Procédés Appliqués aux Matériaux (IPAM), Université de Limoges (UNILIM)-Université de Limoges (UNILIM), Université Djilali Liabès [Sidi-Bel-Abbès], Axe 3 : organisation structurale multiéchelle des matériaux (SPCTS-AXE3), Science des Procédés Céramiques et de Traitements de Surface (SPCTS), Institut des Procédés Appliqués aux Matériaux (IPAM), Université de Limoges (UNILIM)-Université de Limoges (UNILIM)-Ecole Nationale Supérieure de Céramique Industrielle (ENSCI)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Limoges (UNILIM)-Institut des Procédés Appliqués aux Matériaux (IPAM), and Université de Limoges (UNILIM)-Université de Limoges (UNILIM)-Ecole Nationale Supérieure de Céramique Industrielle (ENSCI)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Limoges (UNILIM)

Subjects
Materials science, Magnetic, Current, Extrapolation, Field, Thermodynamics, YBa2Cu3O7−δ Synthesis, 02 engineering and technology, Conductivity, 01 natural sciences, Electrical resistivity and conductivity, 0103 physical sciences, Materials Chemistry, Ceramic, Porous ceramic-limited grain growth, 010302 applied physics, Superconductivity, Process Chemistry and Technology, Metallurgy, Microcracks, [CHIM.MATE]Chemical Sciences/Material chemistry, A. Sintering, 021001 nanoscience & nanotechnology, Microstructure, Grain size, Critical, Surfaces, Coatings and Films, Electronic, Optical and Magnetic Materials, visual_art, Volume fraction, Ceramics and Composites, visual_art.visual_art_medium, Superconductor, 0210 nano-technology
Abstract

The value of critical current density at 77 K in “zero” applied field ( J c ) characterizing the superconducting state for YBa 2 Cu 3 O 7− δ ceramics is closely related to the microstructure. The interrelationships between the microstructural factors such as pore volume fraction, oxygen content, average grain size, are complex. However, these factors also influence the normal state resistivity measured at room temperature ( ρ 300 ). We demonstrate how the current carrying cross section influences Jc and ρ 300 in a similar way. Data, reported for two classes of YBa 2 Cu 3 O 7− δ : small grain porous ceramics and larger-grain denser ceramics, reveal an approximate linear relation between ρ 300 K and J c . Extrapolation of this relation to a fully dense small grain YBa 2 Cu 3 O 7− δ ceramic yields values of ρ 300 = 0.4 mΩ cm and J c = 10 3 A cm −2 .

Published
2012

6. Physical-chemistry of silica/alkaline silicate interactions during consolidation. Part 1: Effect of cation size

Author

Sylvie Rossignol, Monique Tohoué Tognonvi, Julien Soro, Rossignol, Sylvie, Groupe d'Etudes des Matériaux Hétérogènes (GEMH), Université de Limoges (UNILIM)-Institut des Procédés Appliqués aux Matériaux (IPAM), Université de Limoges (UNILIM)-Université de Limoges (UNILIM), Axe 3 : organisation structurale multiéchelle des matériaux (SPCTS-AXE3), Science des Procédés Céramiques et de Traitements de Surface (SPCTS), Institut des Procédés Appliqués aux Matériaux (IPAM), Université de Limoges (UNILIM)-Université de Limoges (UNILIM)-Ecole Nationale Supérieure de Céramique Industrielle (ENSCI)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Limoges (UNILIM)-Institut des Procédés Appliqués aux Matériaux (IPAM), and Université de Limoges (UNILIM)-Université de Limoges (UNILIM)-Ecole Nationale Supérieure de Céramique Industrielle (ENSCI)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Limoges (UNILIM)

Subjects
Materials science, Potassium, Inorganic chemistry, Hydration shell, Ionic bonding, chemistry.chemical_element, 02 engineering and technology, Ionic bonds, 010402 general chemistry, 01 natural sciences, chemistry.chemical_compound, Alkaline silicate solution, Materials Chemistry, Solubility, Potassium silicate, [CHIM.MATE] Chemical Sciences/Material chemistry, [CHIM.MATE]Chemical Sciences/Material chemistry, 021001 nanoscience & nanotechnology, Condensed Matter Physics, Silicate, 0104 chemical sciences, Electronic, Optical and Magnetic Materials, Compressive strength, Solvation shell, chemistry, Agglomerate, Silica sand, Ceramics and Composites, Consolidated materials, 0210 nano-technology
Abstract

International audience; The purpose of this work is to identify the effect of the cation nature on mechanisms of the sand consolidation with alkaline silicate solution at low temperature (70 °C). Three diluted lithium, sodium and potassium silicate solutions with [Si] = 2.8 mol/l were used to agglomerate sand composed of grains which mean diameter is 340 μm. According to the cation, different behaviors were observed in terms of the drying time and the material cohesion. Essentially, the drying time increases with decreasing cation size. In contrast, the compressive strength raises when the cation size increases inducing intra-granular rupture highlighted by SEM observations. This could find an explanation in the cation hydration sphere of cations. The strength of the cation-water electrostatic interaction becomes less important as the size of the cations increase leading to more ionic bonds. Despite their strong consolidation, potassium-based materials have a high solubility in water. This result is consistent with the ionic nature of bonds

Published
2012

7. Irradiation externe aux ions lourds de céramiques et vitrocéramiques d'apatite silicatée au néodyme

Author

J.-L. Dussossoy, Daniel Caurant, Pascal Loiseau, Clara Grygiel, S. Peuget, Nolwenn Chouard, Odile Majérus, Groupe d'Etudes des Matériaux Hétérogènes (GEMH), Université de Limoges (UNILIM)-Institut des Procédés Appliqués aux Matériaux (IPAM), Université de Limoges (UNILIM)-Université de Limoges (UNILIM), Laboratoire de Chimie Appliquée de l'État Solide (LCAES), Ecole Nationale Supérieure de Chimie de Paris - Chimie ParisTech-PSL (ENSCP), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS), Institut de minéralogie et de physique des milieux condensés (IMPMC), Université Pierre et Marie Curie - Paris 6 (UPMC)-IPG PARIS-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Laboratoire des Matériaux et Procédés Actifs (LMPA), Département de recherche sur les technologies pour l'enrichissement, le démantèlement et les déchets (DE2D), CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Centre de recherche sur les Ions, les MAtériaux et la Photonique (CIMAP - UMR 6252), Centre National de la Recherche Scientifique (CNRS)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Caen Normandie (UNICAEN), Normandie Université (NU), Service d'Etudes du Comportement des Matériaux de Conditionnement (SECM), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Université Pierre et Marie Curie - Paris 6 (UPMC)-Université Paris Diderot - Paris 7 (UPD7)-Institut de Physique du Globe de Paris (IPG Paris)-Centre National de la Recherche Scientifique (CNRS), Département de recherche sur les Procédés et Matériaux pour les Environnements complexes (DPME), Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche sur les Matériaux Avancés (IRMA), Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Institut national des sciences appliquées Rouen Normandie (INSA Rouen Normandie), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Rouen Normandie (UNIROUEN), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS), Institut de Recherche de Chimie Paris (IRCP), Ecole Nationale Supérieure de Chimie de Paris- Chimie ParisTech-PSL (ENSCP)-Centre National de la Recherche Scientifique (CNRS)-Ministère de la Culture (MC), and Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Nuclear and High Energy Physics, Materials science, Ion beam, Analytical chemistry, 02 engineering and technology, 01 natural sciences, Apatite, 010305 fluids & plasmas, law.invention, Ion, chemistry.chemical_compound, symbols.namesake, Swift heavy ion, law, 0103 physical sciences, [CHIM]Chemical Sciences, General Materials Science, Irradiation, ComputingMilieux_MISCELLANEOUS, Glass-ceramic, [CHIM.MATE]Chemical Sciences/Material chemistry, 021001 nanoscience & nanotechnology, Silicate, Nuclear Energy and Engineering, chemistry, visual_art, [PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], visual_art.visual_art_medium, symbols, 0210 nano-technology, Raman spectroscopy
Abstract

This work aims at comparing the damage induced in the Nd silicate apatite ceramic (Ca2Nd8(SiO4)6O2) by medium energy (ME) and swift heavy ion (SHI) irradiations to evaluate the effects of nuclear collisions and intense electronic excitations for ME ions and SHI ions respectively. The macroscopic induced changes were studied as a function of the fluence by swelling and hardness measurements, whereas structural modifications were followed by X-ray diffraction, Raman spectroscopy and grazing incidence EXAFS (Nd L3-edge). At ME (1.9–6.75 MeV Au ions), radiation-induced amorphization occurred above 6.22 × 1013 Au/cm2 associated with a volume expansion of about 8% and a drop of 37% in hardness. At SHI (90 MeV Xe ions or 35 MeV Ar ions), similar macroscopic and structural changes were observed. The electronic stopping power threshold of Nd silicate apatite for amorphization was assessed at about Se = 5 keV/nm. As apatite crystals containing actinides could be present in rare-earths rich nuclear glasses, SHI irradiation with Xe (995 MeV) ions was also used to damage the Nd silicate apatite crystals dispersed in a soda-lime aluminoborosilicate simplified nuclear glass over a depth of about 60 μm, to evaluate the possible formation of cracks in the residual glass due to crystals swelling. In spite of apatite crystals amorphization under SHI irradiation in the glass-ceramics, no cracking was observed in the glassy phase even close to the biggest crystals which could be explained by strain relaxation in the glass due to plastic deformation (creep) induced by SHI ion beam.

Published
2019

8. Numerical modeling of spark plasma sintering—Discussion on densification mechanism identification and generated porosity gradients

Author

Guy Antou, Alexandre Maitre, J. Diatta, Nicolas Pradeilles, Axe 4 : céramiques sous contraintes environnementales (SPCTS-AXE4), Science des Procédés Céramiques et de Traitements de Surface (SPCTS), Institut des Procédés Appliqués aux Matériaux (IPAM), Université de Limoges (UNILIM)-Université de Limoges (UNILIM)-Ecole Nationale Supérieure de Céramique Industrielle (ENSCI)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Limoges (UNILIM)-Institut des Procédés Appliqués aux Matériaux (IPAM), and Université de Limoges (UNILIM)-Université de Limoges (UNILIM)-Ecole Nationale Supérieure de Céramique Industrielle (ENSCI)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Limoges (UNILIM)

Subjects
010302 applied physics, Materials science, Pellets, Sintering, Spark plasma sintering, [CHIM.MATE]Chemical Sciences/Material chemistry, 02 engineering and technology, 021001 nanoscience & nanotechnology, 01 natural sciences, [SPI.MAT]Engineering Sciences [physics]/Materials, Temperature gradient, Deformation mechanism, Creep, visual_art, 0103 physical sciences, Materials Chemistry, Ceramics and Composites, visual_art.visual_art_medium, Ceramic, Composite material, 0210 nano-technology, Porosity, ComputingMilieux_MISCELLANEOUS
Abstract

A multi-physical numerical model of the SPS process has been developed in order to evaluate electrical, thermal and mechanical fields undergone by the powder during sintering. The reliability of this numerical model has been validated by comparison with experimental data carried out on a submicrometric alpha alumina powder. This numerical approach is applied to achieve a critical analysis of the main methodologies used in the literature for the identification of the densification parameters, and the possible misinterpretations of involved deformation mechanisms. Moreover, as shown during sintering of alumina pellets of larger diameter (50 mm in diameter), the induced porosity gradient seems to be mainly correlated to the existence of thermal gradient within the powder, and in a lesser level to stress gradient. Consequently, the temperature gradient seems to be a crucial point to be controlled during SPS process of large size samples in order to obtain fine and homogeneous microstructure.

Published
2017

9. Amine-functionalized polycarbosilane hybrids for CO2-selective membranes

Author

Samuel Bernard, Yuji Iwamoto, Zineb Mouline, Kota Asai, Sawao Honda, Yusuke Daiko, Institut Européen des membranes (IEM), Centre National de la Recherche Scientifique (CNRS)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Université Montpellier 2 - Sciences et Techniques (UM2)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM), Nagoya Institute of Technology (NIT), Axe 4 : céramiques sous contraintes environnementales (SPCTS-AXE4), Science des Procédés Céramiques et de Traitements de Surface (SPCTS), Université de Limoges (UNILIM)-Ecole Nationale Supérieure de Céramique Industrielle (ENSCI)-Institut des Procédés Appliqués aux Matériaux (IPAM), Université de Limoges (UNILIM)-Université de Limoges (UNILIM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Limoges (UNILIM)-Ecole Nationale Supérieure de Céramique Industrielle (ENSCI)-Institut des Procédés Appliqués aux Matériaux (IPAM), Université de Limoges (UNILIM)-Université de Limoges (UNILIM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Institut des Procédés Appliqués aux Matériaux (IPAM), Université de Limoges (UNILIM)-Université de Limoges (UNILIM)-Ecole Nationale Supérieure de Céramique Industrielle (ENSCI)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Limoges (UNILIM)-Institut des Procédés Appliqués aux Matériaux (IPAM), and Université de Limoges (UNILIM)-Université de Limoges (UNILIM)-Ecole Nationale Supérieure de Céramique Industrielle (ENSCI)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Limoges (UNILIM)

Subjects
Thermogravimetric analysis, Materials science, Sorbent, Silanes, Facilitated diffusion, Sorption, [CHIM.MATE]Chemical Sciences/Material chemistry, 02 engineering and technology, 010402 general chemistry, 021001 nanoscience & nanotechnology, 01 natural sciences, [SPI.MAT]Engineering Sciences [physics]/Materials, 0104 chemical sciences, Membrane gas separation, chemistry.chemical_compound, Adsorption, Membrane, chemistry, Chemical engineering, Materials Chemistry, Ceramics and Composites, Organic chemistry, 0210 nano-technology, ComputingMilieux_MISCELLANEOUS
Abstract

Commercially available polycarbosilane has been chemically modified with primary and secondary amino silane derivatives in order to provide amine-functionalized polycarbosilane as hydrophobic solid sorbent capable of reversibly capturing CO 2 from flue gas streams. CO 2 uptake by the samples was investigated at the molecular level using thermogravimetric analysis under CO 2 atmosphere, in situ DRIFTS analysis, and CO 2 sorption isotherm. The reaction paths and sorption mechanisms were examined by comparing with the CO 2 adsorbing behaviors previously studied for amine-functionalized SiO 2 , and proven to be related to the presence of adsorbed water, as well as the nature of the grafted amino silanes. With effective CO 2 adsorption rate, regeneration capacity at 40–50 °C, and lesser sensitivity to moist due to its hydrophobic Si-C backbone, secondary amine-functionalized polycarbosilane hybrids have potential applications in membrane gas separation through facilitated transport of CO 2 .

Published
2017

10. IMPACT: A novel device for in-situ thermo-mechanical investigation of materials under concentrated sunlight

Author

Bernard Claudet, Damien André, Thierry Chotard, Marc Huger, Emmanuel Guillot, Yasmine Lalau, Alain Proust, Olivier Faugeroux, Axe 4 : céramiques sous contraintes environnementales (SPCTS-AXE4), Science des Procédés Céramiques et de Traitements de Surface (SPCTS), Institut des Procédés Appliqués aux Matériaux (IPAM), Université de Limoges (UNILIM)-Université de Limoges (UNILIM)-Ecole Nationale Supérieure de Céramique Industrielle (ENSCI)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Limoges (UNILIM)-Institut des Procédés Appliqués aux Matériaux (IPAM), Université de Limoges (UNILIM)-Université de Limoges (UNILIM)-Ecole Nationale Supérieure de Céramique Industrielle (ENSCI)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Limoges (UNILIM), Université de Limoges (UNILIM)-Ecole Nationale Supérieure de Céramique Industrielle (ENSCI)-Institut des Procédés Appliqués aux Matériaux (IPAM), Université de Limoges (UNILIM)-Université de Limoges (UNILIM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Limoges (UNILIM)-Ecole Nationale Supérieure de Céramique Industrielle (ENSCI)-Institut des Procédés Appliqués aux Matériaux (IPAM), and Université de Limoges (UNILIM)-Université de Limoges (UNILIM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Sunlight, Work (thermodynamics), Materials science, Renewable Energy, Sustainability and the Environment, business.industry, 020209 energy, Mechanical engineering, [CHIM.MATE]Chemical Sciences/Material chemistry, 02 engineering and technology, 021001 nanoscience & nanotechnology, 7. Clean energy, [SPI.MAT]Engineering Sciences [physics]/Materials, Surfaces, Coatings and Films, Electronic, Optical and Magnetic Materials, Characterization (materials science), Optics, Acoustic emission, Mechanical stability, Range (aeronautics), Concentrated solar power, 0202 electrical engineering, electronic engineering, information engineering, 0210 nano-technology, business, ComputingMilieux_MISCELLANEOUS, Thermo mechanical
Abstract

A promising route toward affordable and efficient solar energy conversion lies in the development of the high temperature Concentrated Solar Power (CSP) tower. The extreme thermal stress conditions to which the tower receivers may be submitted raise the question of the ability of these components to efficiently perform over extended periods of time. Conventional methods commonly used to assess the mechanical stability and lifetime of these components involve laboratory testing, which suffers from the fundamental inability of these methods to effectively reproduce the real operating conditions. In this work, we suggest an original set-up based upon the use of acoustic emission for in-situ thermo-mechanical investigation of receiver materials exposed to concentrated solar irradiation, named IMPACT (In-situ thermo-Mechanical Probe by ACoustic Tracking). The ability of this set-up to precisely track the nature, the location and the dynamics of mechanical defects in the receiver material is assessed. Implications for future characterization tools aimed at obtaining an in-depth understanding of the thermo-mechanical behaviour of a wide range of materials in real-working operation is also discussed.

Published
2017

11. Substitution of aluminous cement by calcium carbonates in presence of carboxylic acid

Author

A. Benhammou, Y. Abouliatim, L. Nibou, Abdelmjid Abourriche, A. Smith, J.P. Bonnet, Y. El Hafiane, B. Tanouti, Axe 1 : procédés céramiques (SPCTS-AXE1), Science des Procédés Céramiques et de Traitements de Surface (SPCTS), Institut des Procédés Appliqués aux Matériaux (IPAM), Université de Limoges (UNILIM)-Université de Limoges (UNILIM)-Ecole Nationale Supérieure de Céramique Industrielle (ENSCI)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Limoges (UNILIM)-Institut des Procédés Appliqués aux Matériaux (IPAM), Université de Limoges (UNILIM)-Université de Limoges (UNILIM)-Ecole Nationale Supérieure de Céramique Industrielle (ENSCI)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Limoges (UNILIM), Laboratoire Matériaux Procédés Environnement Qualité (LMPEQ), Ecole Nationale des Sciences Appliquées [Safi] (ENSA)-Université Cadi Ayyad [Marrakech] (UCA), Laboratoire de la Matière Condensée et de l’Environnement (LMACE), and Université Cadi Ayyad [Marrakech] (UCA)

Subjects
Materials science, Aluminate, Carboxylic acid, Mineralogy, chemistry.chemical_element, Dispersant, 02 engineering and technology, Calcium, 01 natural sciences, [SPI.MAT]Engineering Sciences [physics]/Materials, chemistry.chemical_compound, Calcium aluminate cement, 0103 physical sciences, General Materials Science, Microstructure, Civil and Structural Engineering, 010302 applied physics, Cement, chemistry.chemical_classification, Building and Construction, Calcium carbonates, 021001 nanoscience & nanotechnology, Mass Percentage, Calcium carbonate, chemistry, Chemical engineering, 0210 nano-technology, Mechanical strength
Abstract

International audience; This paper presents results concerning the partial substitution of a calcium aluminate cement by calcium carbonate. The experimental parameters monitored in this study are the mechanical properties, the microstructure evolution through density measurements and the structure through analysis by X-ray diffraction. The major results of this study are the following: (1) It is possible to substitute a portion (10 wt%) of an aluminous cement by calcium carbonate, while improving the mechanical properties of the hardened material. This is achieved with a mass percentage of the carboxylic acid between 1 and 5%, relative to the dry mass, which acts as a good dispersant and leads therefore to densification of the hardened material. (2) When the mix consists of 50 wt% of aluminous cement and 50 wt% of calcium carbonate, the mechanical properties of the cured material are low and this happens whatever the percentage of added dispersant is.

Published
2017

12. Influence of silicate solution preparation on geomaterials based on brick clay materials

Author

Emmanuel Joussein, Sylvie Rossignol, Julie Peyne, J. Doudeau, J. Gautron, Axe 3 : organisation structurale multiéchelle des matériaux (SPCTS-AXE3), Science des Procédés Céramiques et de Traitements de Surface (SPCTS), Institut des Procédés Appliqués aux Matériaux (IPAM), Université de Limoges (UNILIM)-Université de Limoges (UNILIM)-Ecole Nationale Supérieure de Céramique Industrielle (ENSCI)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Limoges (UNILIM)-Institut des Procédés Appliqués aux Matériaux (IPAM), and Université de Limoges (UNILIM)-Université de Limoges (UNILIM)-Ecole Nationale Supérieure de Céramique Industrielle (ENSCI)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Limoges (UNILIM)

Subjects
Materials science, 0211 other engineering and technologies, Mineralogy, 02 engineering and technology, Raw material, [SPI.MAT]Engineering Sciences [physics]/Materials, chemistry.chemical_compound, symbols.namesake, Aluminosilicate, 021105 building & construction, Materials Chemistry, Fourier transform infrared spectroscopy, ComputingMilieux_MISCELLANEOUS, Alkaline earth metal, Brick, [CHIM.MATE]Chemical Sciences/Material chemistry, 021001 nanoscience & nanotechnology, Condensed Matter Physics, Alkali metal, 6. Clean water, Silicate, Electronic, Optical and Magnetic Materials, chemistry, Chemical engineering, Ceramics and Composites, symbols, 0210 nano-technology, Raman spectroscopy
Abstract

Brick clay mixtures are raw materials with the potential for use in geomaterials other than tiles or bricks. This study concerns the effect of mixed alkali cation solutions on the polycondensation reactions of geomaterials based on brick clay mixtures. To evidence the feasibility and the understanding of such effects, FTIR and Raman spectroscopy, thermal analyses and compressive tests were investigated to reveal the performance of the alkaline solution and aluminosilicate source. The various solutions used contained different siliceous species (rings, chains) that modified the polycondensation reactions and the Si-O-Ca bond formation. The effect of the polarizability of the alkaline and alkaline earth solutions must be controlled to enhance the final properties. Better mechanical properties were obtained with a low water content.

Published
2017

13. Effects of metakaolin addition on geopolymer prepared from natural kaolinitic clay

Author

Ali Sdiri, Sylvie Rossignol, Samir Bouaziz, Emmanuel Joussein, Samira Selmani, Axe 3 : organisation structurale multiéchelle des matériaux (SPCTS-AXE3), Science des Procédés Céramiques et de Traitements de Surface (SPCTS), Institut des Procédés Appliqués aux Matériaux (IPAM), Université de Limoges (UNILIM)-Université de Limoges (UNILIM)-Ecole Nationale Supérieure de Céramique Industrielle (ENSCI)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Limoges (UNILIM)-Institut des Procédés Appliqués aux Matériaux (IPAM), and Université de Limoges (UNILIM)-Université de Limoges (UNILIM)-Ecole Nationale Supérieure de Céramique Industrielle (ENSCI)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Limoges (UNILIM)

Subjects
Materials science, Mineralogy, 020101 civil engineering, 02 engineering and technology, engineering.material, [SPI.MAT]Engineering Sciences [physics]/Materials, 0201 civil engineering, law.invention, chemistry.chemical_compound, Geochemistry and Petrology, law, Kaolinite, Calcination, ComputingMilieux_MISCELLANEOUS, Metakaolin, Geology, [CHIM.MATE]Chemical Sciences/Material chemistry, 021001 nanoscience & nanotechnology, Silicate, Amorphous solid, Geopolymer, Compressive strength, chemistry, Chemical engineering, Illite, engineering, 0210 nano-technology
Abstract

This study was undertaken to valorize naturally occurring clays in the synthesis of new geopolymers materials from the mixture of commercial metakaolins and calcined clays (550 °C). For the purpose of this work, three raw clay samples were collected from various locations in Tunisia where clayey deposits extended over large areas. A simple synthesis method was adopted by mixing calcined clays and metakaolins with an alkali silicate solution of the desired Si/K ratio. The obtained geopolymers were stored for subsequent analyses. Both metakaolins and prepared geopolymers were characterized by FTIR, XRD, TG-DTA, SEM and mechanical properties. It was demonstrated that samples based on clay and different metakaolins present amorphous consolidated geopolymer materials. Also, the obtained geopolymer materials have a smooth and amorphous appearance characterizing the polycondensation reactions. Addition of natural clay decreased the compressive strength of the geopolymer materials, because of impurities (i.e. illite, calcite, iron). Despite their low kaolinite contents, raw clays from Tunisia provided good geopolymers in the presence of metakaolins and alkaline solution.

Published
2017

14. Effect of the current pulse pattern during heating in a spark plasma sintering device: Experimental and numerical modeling approaches

Author

Nicolas Pradeilles, Guy Antou, Alexandre Maitre, J. Diatta, F. Courreges, M. Georges, Axe 4 : céramiques sous contraintes environnementales (SPCTS-AXE4), Science des Procédés Céramiques et de Traitements de Surface (SPCTS), Institut des Procédés Appliqués aux Matériaux (IPAM), Université de Limoges (UNILIM)-Université de Limoges (UNILIM)-Ecole Nationale Supérieure de Céramique Industrielle (ENSCI)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Limoges (UNILIM)-Institut des Procédés Appliqués aux Matériaux (IPAM), and Université de Limoges (UNILIM)-Université de Limoges (UNILIM)-Ecole Nationale Supérieure de Céramique Industrielle (ENSCI)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Limoges (UNILIM)

Subjects
Materials science, Instrumentation, Joule effect, Spark plasma sintering, 02 engineering and technology, Industrial and Manufacturing Engineering, [SPI.MAT]Engineering Sciences [physics]/Materials, symbols.namesake, Optics, Thermal, Electronic engineering, ComputingMilieux_MISCELLANEOUS, business.industry, 020502 materials, Metals and Alloys, Process (computing), [CHIM.MATE]Chemical Sciences/Material chemistry, 021001 nanoscience & nanotechnology, Galvanometer, Finite element method, Computer Science Applications, 0205 materials engineering, Modeling and Simulation, Ceramics and Composites, symbols, 0210 nano-technology, business, Intensity (heat transfer)
Abstract

The operating features of the current generator during Spark Plasma Sintering (SPS) process are carefully studied thanks to the use of a specific instrumentation. It is shown that the current pulse pattern characteristics identified here for a Dr. Sinter 825 apparatus are transposable to other Dr. Sinter devices whatever their electrical powers. Particularly, thanks to the highlighting of the characteristic logarithmic decrease of the ratio of rms to average electrical values, it is possible, for users of SPS devices, to determine the imposed rms intensity from the average intensity measured by the galvanometer of the apparatus without additional electrical instrumentation. Moreover, as shown by a numerical approach, the delivered rms intensity directly correlated to the pulse pattern characteristics is a key parameter that controls the heating process induced by the Joule effect. Hence, a reliable numerical model is established with an accurate assessment of the heating rate and of the thermal gradients.

Published
2017

15. The effect of furnace and flash heating on COx argillite for the synthesis of alkali-activated binders

Author

Emmanuel Joussein, Sylvie Rossignol, Ameni Gharzouni, Isabel Sobrados, Xavier Bourbon, C. Dupuy, N. Texier-Mandoki, Axe 3 : organisation structurale multiéchelle des matériaux (SPCTS-AXE3), Science des Procédés Céramiques et de Traitements de Surface (SPCTS), Université de Limoges (UNILIM)-Ecole Nationale Supérieure de Céramique Industrielle (ENSCI)-Institut des Procédés Appliqués aux Matériaux (IPAM), Université de Limoges (UNILIM)-Université de Limoges (UNILIM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Limoges (UNILIM)-Ecole Nationale Supérieure de Céramique Industrielle (ENSCI)-Institut des Procédés Appliqués aux Matériaux (IPAM), Université de Limoges (UNILIM)-Université de Limoges (UNILIM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Axe 1 : procédés céramiques (SPCTS-AXE1), Institut des Procédés Appliqués aux Matériaux (IPAM), Université de Limoges (UNILIM)-Université de Limoges (UNILIM)-Ecole Nationale Supérieure de Céramique Industrielle (ENSCI)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Limoges (UNILIM)-Institut des Procédés Appliqués aux Matériaux (IPAM), and Université de Limoges (UNILIM)-Université de Limoges (UNILIM)-Ecole Nationale Supérieure de Céramique Industrielle (ENSCI)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Limoges (UNILIM)

Subjects
Materials science, Strategy and Management, Mineralogy, 020101 civil engineering, Flash calcination, 02 engineering and technology, engineering.material, Heat treatment, Industrial and Manufacturing Engineering, [SPI.MAT]Engineering Sciences [physics]/Materials, 0201 civil engineering, law.invention, chemistry.chemical_compound, Argillite, law, 27 Al NMR, Kaolinite, Calcination, Chlorite, ComputingMilieux_MISCELLANEOUS, Metakaolin, General Environmental Science, Renewable Energy, Sustainability and the Environment, Muscovite, Metallurgy, Furnace, [CHIM.MATE]Chemical Sciences/Material chemistry, 021001 nanoscience & nanotechnology, chemistry, Alkali-activated, Illite, engineering, Pyrite, 0210 nano-technology, Clay minerals
Abstract

A considerable quantity of Callovo-Oxfordian (COx) argillite will be excavated due to deep geological radioactive waste disposal. Till now, there is no viable solution to make use of the excavated argillite. This paper investigates the possibility of producing alkali-activated materials based on argillite. The raw argillite is mainly composed of illite, smectite, muscovite and traces of kaolinite and chlorite. In addition, it contains carbonates, quartz, plagioclase and pyrite. At first, argillite was ground and thermally treated at different temperatures ranging from 600 °C to 800 °C and from 600 °C to 750 °C with furnace and flash processes, respectively. Then, a comparative study of the effect of the two heating processes on the physical, chemical and structural characteristics of argillite was undertaken. It was shown that in the case of furnace heat treatment, a heating between 700 °C and 800 °C leads to the full dehydroxylation of clay minerals (illite-smectite, illite/mica, kaolinite and chlorite) and the total transformation of octahedral aluminum to tetrahedral one. However, flash treatment induces partial structural dehydroxylation of argillite clay minerals regardless of the temperature. Finally, it was demonstrated that it is possible to produce alkali-activated materials from a mixture comprising of 50% of raw argillite and 50% of metakaolin and from calcined argillite regardless of the heat treatment process and the applied temperature.

Published
2017

16. Study of borosilicate glaze opacification by phosphates using Kubelka-Munk model

Author

Agnès Smith, Y. Abouliatim, A. Benhammou, Y. El Hafiane, Thierry Chartier, A. Abourriche, L. Nibou, Mohamed Mesnaoui, Laboratoire Matériaux Procédés Environnement Qualité (LMPEQ), Ecole Nationale des Sciences Appliquées [Safi] (ENSA)-Université Cadi Ayyad [Marrakech] (UCA), Science des Procédés Céramiques et de Traitements de Surface (SPCTS), Université de Limoges (UNILIM)-Ecole Nationale Supérieure de Céramique Industrielle (ENSCI)-Institut des Procédés Appliqués aux Matériaux (IPAM), Université de Limoges (UNILIM)-Université de Limoges (UNILIM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Axe 1 : procédés céramiques (SPCTS-AXE1), Université de Limoges (UNILIM)-Université de Limoges (UNILIM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Limoges (UNILIM)-Ecole Nationale Supérieure de Céramique Industrielle (ENSCI)-Institut des Procédés Appliqués aux Matériaux (IPAM), Laboratoire de la Matière Condensée et de l’Environnement (LMACE), Université Cadi Ayyad [Marrakech] (UCA), Institut des Procédés Appliqués aux Matériaux (IPAM), Université de Limoges (UNILIM)-Université de Limoges (UNILIM)-Ecole Nationale Supérieure de Céramique Industrielle (ENSCI)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Limoges (UNILIM), and Université de Limoges (UNILIM)-Université de Limoges (UNILIM)-Ecole Nationale Supérieure de Céramique Industrielle (ENSCI)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Limoges (UNILIM)-Institut des Procédés Appliqués aux Matériaux (IPAM)

Subjects
Materials science, Opacity, Scanning electron microscope, Analytical chemistry, 02 engineering and technology, 010402 general chemistry, 01 natural sciences, Light scattering, Phosphates, Optics, Materials Chemistry, Kubelka-Munk, Opacification, Borosilicate glaze, Scattering, business.industry, Borosilicate glass, Process Chemistry and Technology, Glaze, Devitrification, [CHIM.MATE]Chemical Sciences/Material chemistry, 021001 nanoscience & nanotechnology, 0104 chemical sciences, Surfaces, Coatings and Films, Electronic, Optical and Magnetic Materials, Ceramics and Composites, Diffuse reflection, 0210 nano-technology, business
Abstract

International audience; The aim of this work was to study the effects of additions of sodium metaphospahte (1–50 Wt.%) on optical properties of a conventional borosilicate glaze.The optical properties were evaluated by diffuse reflectance measurements. The absorption and the scattering properties of the obtained glazes, were explained through the Kubelka-Munk model. The structural and microstructural properties were determined by X-ray diffraction and Scanning Electron Microscopy. It was shown that white opaque borosilicate glazes can be obtained for an addition of 5 Wt% to 50 Wt% of sodium metaphosphate and 20 Wt% seemed the optimum amount to obtain a perfect white opacity. The opacification process is based on the light scattering phenomenon wherein the nature of the scattering centers vary depending on the amount of sodium metaphosphate addition. In the case of 20 Wt% scattering centers have been identified as Ca10(PO4)6O and NaCa(PO4) crystals formed by a devitrification process.

Published
2017

17. Development of hydroxyapatite coatings by solution precursor plasma spray process and their microstructural characterization

Author

Lech Pawlowski, Catalin Constantinescu, Paweł Sokołowski, Gisèle Laure Lecomte-Nana, Alain Denoirjean, Rolando T. Candidato, Axe 2 : procédés plasmas et lasers (SPCTS-AXE2), Science des Procédés Céramiques et de Traitements de Surface (SPCTS), Institut des Procédés Appliqués aux Matériaux (IPAM), Université de Limoges (UNILIM)-Université de Limoges (UNILIM)-Ecole Nationale Supérieure de Céramique Industrielle (ENSCI)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Limoges (UNILIM)-Institut des Procédés Appliqués aux Matériaux (IPAM), and Université de Limoges (UNILIM)-Université de Limoges (UNILIM)-Ecole Nationale Supérieure de Céramique Industrielle (ENSCI)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Limoges (UNILIM)

Subjects
Materials science, 02 engineering and technology, engineering.material, 01 natural sciences, [SPI.MAT]Engineering Sciences [physics]/Materials, Crystal, Crystallinity, Solution precursor plasma spray, Coating, Phase (matter), 0103 physical sciences, Materials Chemistry, ComputingMilieux_MISCELLANEOUS, Deposition (law), 010302 applied physics, Metallurgy, [CHIM.MATE]Chemical Sciences/Material chemistry, Surfaces and Interfaces, General Chemistry, Plasma, 021001 nanoscience & nanotechnology, Condensed Matter Physics, Microstructure, Surfaces, Coatings and Films, Chemical engineering, engineering, 0210 nano-technology
Abstract

Solution precursor plasma spraying (SPPS) is a promising method of obtaining coatings with unique microstructural features. The present study reports about the development of hydroxyapatite (HA) coatings by SPPS using water-based calcium-phosphate solution and about the analyses of their microstructure. X-ray diffraction (XRD) analysis showed that HA was the major crystal phase of the coatings, being present in the range from 95% to 98%. The coatings of greater HA content were obtained while spraying using shorter spray distance. The coating crystallinity ranges from 24% to 69% depending on the temperature at deposition. An increase of the temperature results in greater crystallinity. The obtained coatings' microstructures may be described by dome-like surface and by the columnar-like cross-section when using precursor with low concentration. The use of concentrated solution precursor results in cauliflower-like structures composed of agglomerated fragmented shells and fine spherical particles. The possible phenomena occurring in droplets in contact with the plasma jet and the coating build-up mechanisms were tentatively explained.

Published
2017

18. Understanding and identifying the oxygen transport mechanisms through a mixed-conductor membrane

Author

Pierre-Marie Geffroy, Thierry Chartier, Nicolas Richet, Eric Blond, Axe 1 : procédés céramiques (SPCTS-AXE1), Science des Procédés Céramiques et de Traitements de Surface (SPCTS), Institut des Procédés Appliqués aux Matériaux (IPAM), Université de Limoges (UNILIM)-Université de Limoges (UNILIM)-Ecole Nationale Supérieure de Céramique Industrielle (ENSCI)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Limoges (UNILIM)-Institut des Procédés Appliqués aux Matériaux (IPAM), Université de Limoges (UNILIM)-Université de Limoges (UNILIM)-Ecole Nationale Supérieure de Céramique Industrielle (ENSCI)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Limoges (UNILIM), Laboratoire de Mécanique des Systèmes et des Procédés (LMSP), Centre National de la Recherche Scientifique (CNRS), Centre de Recherche Claude Delorme [Jouy-en-Josas] (CRCD), Air Liquide [Siège Social], Laboratoire Pluridisciplinaire de Recherche en Ingénierie des Systèmes, Mécanique et Energétique ( PRISME ), Université d'Orléans ( UO ) -Ecole Nationale Supérieure d'Ingénieurs de Bourges ( ENSI Bourges ), Centre de Recherche Claude Delorme [Jouy-en-Josas] ( CRCD ), Université de Limoges (UNILIM)-Ecole Nationale Supérieure de Céramique Industrielle (ENSCI)-Institut des Procédés Appliqués aux Matériaux (IPAM), Université de Limoges (UNILIM)-Université de Limoges (UNILIM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Limoges (UNILIM)-Ecole Nationale Supérieure de Céramique Industrielle (ENSCI)-Institut des Procédés Appliqués aux Matériaux (IPAM), Université de Limoges (UNILIM)-Université de Limoges (UNILIM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Mécanique des Matériaux et Procédés (MMP), Laboratoire de Mécanique Gabriel Lamé (LaMé), Université d'Orléans (UO)-Université de Tours-Institut National des Sciences Appliquées - Centre Val de Loire (INSA CVL), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université d'Orléans (UO)-Université de Tours-Institut National des Sciences Appliquées - Centre Val de Loire (INSA CVL), and Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)

Subjects
General Chemical Engineering, [ SPI.MAT ] Engineering Sciences [physics]/Materials, chemistry.chemical_element, Nanotechnology, [SPI.MECA.MSMECA]Engineering Sciences [physics]/Mechanics [physics.med-ph]/Materials and structures in mechanics [physics.class-ph], 02 engineering and technology, 010402 general chemistry, 01 natural sciences, Oxygen, Industrial and Manufacturing Engineering, [SPI.MECA.MEMA]Engineering Sciences [physics]/Mechanics [physics.med-ph]/Mechanics of materials [physics.class-ph], Oxygen surface exchanges, Oxygen flux, Membrane surface, ComputingMilieux_MISCELLANEOUS, Membranes, Applied Mathematics, Oxygen transport, Oxygen semi-permeation, [CHIM.MATE]Chemical Sciences/Material chemistry, General Chemistry, 021001 nanoscience & nanotechnology, [SPI.MECA.STRU]Engineering Sciences [physics]/Mechanics [physics.med-ph]/Mechanics of the structures [physics.class-ph], 0104 chemical sciences, Mixed conductors, Membrane, Mixed conductor, chemistry, Environmental chemistry, Current (fluid), 0210 nano-technology
Abstract

International audience; Recent developments in oxygen transport membranes have led to a selection of membrane materials or designs to achieve a judicious compromise between the oxygen flux, chemical stability and mechanical performance of membranes under operating conditions. This paper briefly describes the state of the art in the current understanding of oxygen transport through mixed-conductor membranes for oxygen separation. A better understanding of oxygen transport mechanisms, in particular, oxygen exchange at the membrane surface, leads to the identification of relevant key parameters that control the oxygen semi-permeation performance of the membrane. From a rational approach, key parameters are identified and discussed to identify promising membrane materials.

Published
2017

19. Design of ceramic filters using Clay/Sawdust composites: Effect of pore network on the hydraulic permeability

Author

J. C. Sofack, R. T. Tene Fongang, Cristina Leonelli, Ignas Kenfack Tonle, Martine Youmoue, Elie Kamseu, U. Chinje Melo, Sylvie Rossignol, University of Yaoundé [Cameroun], Università degli Studi di Modena e Reggio Emilia (UNIMORE), Axe 3 : organisation structurale multiéchelle des matériaux (SPCTS-AXE3), Science des Procédés Céramiques et de Traitements de Surface (SPCTS), Institut des Procédés Appliqués aux Matériaux (IPAM), Université de Limoges (UNILIM)-Université de Limoges (UNILIM)-Ecole Nationale Supérieure de Céramique Industrielle (ENSCI)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Limoges (UNILIM)-Institut des Procédés Appliqués aux Matériaux (IPAM), and Université de Limoges (UNILIM)-Université de Limoges (UNILIM)-Ecole Nationale Supérieure de Céramique Industrielle (ENSCI)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Limoges (UNILIM)

Subjects
Materials science, Sintering, 02 engineering and technology, 010501 environmental sciences, 01 natural sciences, Flexural strength, Hydraulic conductivity, Hydraulic permeability, Materials Chemistry, Ceramic, Composite material, Porosity, ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences, Filter, Process Chemistry and Technology, [CHIM.MATE]Chemical Sciences/Material chemistry, 021001 nanoscience & nanotechnology, Microstructure, Surfaces, Coatings and Films, Electronic, Optical and Magnetic Materials, Surfaces, Permeability (earth sciences), visual_art, Ceramics and Composites, visual_art.visual_art_medium, Sawdust, Surfaces, Materials Chemistry, 0210 nano-technology
Abstract

Clay based ceramic composite materials with hydraulic permeability were elaborated using sawdust as porogent agent. Their mechanical, morphological, microstructural and pore network properties were investigated. Mixtures in various ratios of two kaolinite clay minerals, Ba (highly plastic) and Va (sand-rich) constitute the five ceramic matrixes studied (CM1, CM2, CM3, CM4 and CM5). Due to their high flexural strength, CM3 and CM4 received 0%, 5%, 10% and 15% sawdust before firing, to improve the porosity of the final matrixes. Results revealed that 900–1000 °C is the range of temperature necessary to get good sintering and flexural strength (≥2 MPa). A typical clay-sawdust based materials (parallepipedic bricks) present porosity ≥40 vol% and 1.5 g/cm 3 density. Characterizations such as FTIR, SEM, MIP and flow permeability of ceramic candles were performed. A Hydraulic permeability of ~10 mDarcy was obtained and the mean pore diameter varies from 0.05 to 0.1 µm, in agreement with the microstructure exhibited by the ceramic candles. In the presence of sawdust, pores with size up to 10 µm were observed, justifying the increase of flowing permeability. The elaborated matrixes are promising candidates for microfiltration.

Published
2017

20. Processing of in situ synthesized polycarbosilane-derived porous SiC using kraft pulp fibers

Author

Hatim Laadoua, François Brouillette, Yves Champavier, Romain Lucas, Sylvie Foucaud, Rachida Zerrouki, Axe 4 : céramiques sous contraintes environnementales (SPCTS-AXE4), Science des Procédés Céramiques et de Traitements de Surface (SPCTS), Université de Limoges (UNILIM)-Ecole Nationale Supérieure de Céramique Industrielle (ENSCI)-Institut des Procédés Appliqués aux Matériaux (IPAM), Université de Limoges (UNILIM)-Université de Limoges (UNILIM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Limoges (UNILIM)-Ecole Nationale Supérieure de Céramique Industrielle (ENSCI)-Institut des Procédés Appliqués aux Matériaux (IPAM), Université de Limoges (UNILIM)-Université de Limoges (UNILIM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Institut des Procédés Appliqués aux Matériaux (IPAM), Université de Limoges (UNILIM)-Université de Limoges (UNILIM)-Ecole Nationale Supérieure de Céramique Industrielle (ENSCI)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Limoges (UNILIM)-Institut des Procédés Appliqués aux Matériaux (IPAM), and Université de Limoges (UNILIM)-Université de Limoges (UNILIM)-Ecole Nationale Supérieure de Céramique Industrielle (ENSCI)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Limoges (UNILIM)

Subjects
Materials science, Hydrosilylation, 02 engineering and technology, 010402 general chemistry, 01 natural sciences, [SPI.MAT]Engineering Sciences [physics]/Materials, law.invention, chemistry.chemical_compound, Magazine, law, General Materials Science, Ceramic, Fiber, Composite material, ComputingMilieux_MISCELLANEOUS, Organosilicon, Mechanical Engineering, [CHIM.MATE]Chemical Sciences/Material chemistry, 021001 nanoscience & nanotechnology, Condensed Matter Physics, 0104 chemical sciences, Monomer, chemistry, Kraft process, Mechanics of Materials, visual_art, visual_art.visual_art_medium, 0210 nano-technology, Pyrolysis
Abstract

SiC ceramics were fabricated using the polymer-derived ceramics route with kraft pulp fibers (KPF) and organosilicon monomers as starting materials. For this, KPF or Propargylated Kraft pulp fibers (PKPF) were used as natural templates to be impregnated with a polycarbosilane (PCS), synthesized in situ thanks to a hydrosilylation reaction. Characterizations of the pyrolyzed materials were carried out at different stages by means of TGA coupled with mass spectrometry, XRD and SEM. Depending on the initial template, either KPF or PKPF, SiC ceramics were generated with a porous network and fiber structures, respectively.

Published
2017

21. White sintered glass-ceramic tiles with improved thermal insulation properties for building applications

Author

Mohammed Binhussain, Mauro Marangoni, Enrico Bernardo, B. Nait-Ali, Paolo Colombo, David S. Smith, Faculdade de Oceanografia, Universidade do Estado do Rio de Janeiro [Rio de Janeiro] (UERJ), Axe 1 : procédés céramiques (SPCTS-AXE1), Science des Procédés Céramiques et de Traitements de Surface (SPCTS), Institut des Procédés Appliqués aux Matériaux (IPAM), Université de Limoges (UNILIM)-Université de Limoges (UNILIM)-Ecole Nationale Supérieure de Céramique Industrielle (ENSCI)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Limoges (UNILIM)-Institut des Procédés Appliqués aux Matériaux (IPAM), Université de Limoges (UNILIM)-Université de Limoges (UNILIM)-Ecole Nationale Supérieure de Céramique Industrielle (ENSCI)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Limoges (UNILIM), Dipartimento di Ingegneria Meccanica-Settore Materiali, and Universita degli Studi di Padova

Subjects
Materials Chemistry2506 Metals and Alloys, Materials science, Sinter-crystallization, 02 engineering and technology, Cool tile, 01 natural sciences, [SPI.MAT]Engineering Sciences [physics]/Materials, law.invention, Thermal barrier coating, Thermal conductivity, Cool roof, law, Thermal insulation, 0103 physical sciences, Materials Chemistry, Composite material, Glass-ceramics, ComputingMilieux_MISCELLANEOUS, 010302 applied physics, Glass-ceramic, business.industry, Glazed tile, Ceramics and Composites, [CHIM.MATE]Chemical Sciences/Material chemistry, 021001 nanoscience & nanotechnology, Thermal conduction, visual_art, Heat transfer, visual_art.visual_art_medium, Tile, Reflective surfaces, 0210 nano-technology, business
Abstract

In order to provide a thermal barrier in an arid environment, highly reflective coatings were deposited on porous substrates made of natural raw materials from Saudi Arabia. Although highly reflective coatings inhibit heat absorption from the incoming sunlight, the body of conventional ceramic tiles warms up to environmental temperature through conduction, convection and radiation. A strategy to reduce the penetration of this heat into the building is to use a highly porous substrate, which reduces the thermal conductivity of the tile, coupled with a highly reflective glaze. The approach leads to the concept of “cool” tiles, aimed at improving the thermal efficiency of buildings. The present paper provides a first example, based on layered wollastonite-hardystonite glass-ceramics developed by double pressing of glass powders and additives followed by sinter-crystallization.

Published
2017

22. Control of shaping and thermal resistance of metakaolin-based geopolymers

Author

Claudio Pettinari, A. Sabbatini, Sylvie Rossignol, Isabel Sobrados, Loïc Vidal, Science des Procédés Céramiques et de Traitements de Surface (SPCTS), Institut des Procédés Appliqués aux Matériaux (IPAM), Université de Limoges (UNILIM)-Université de Limoges (UNILIM)-Ecole Nationale Supérieure de Céramique Industrielle (ENSCI)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Limoges (UNILIM), Instituto de Ciencia de Materiales de Madrid (ICMM), Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), Axe 3 : organisation structurale multiéchelle des matériaux (SPCTS-AXE3), and Université de Limoges (UNILIM)-Université de Limoges (UNILIM)-Ecole Nationale Supérieure de Céramique Industrielle (ENSCI)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Limoges (UNILIM)-Institut des Procédés Appliqués aux Matériaux (IPAM)

Subjects
Thermogravimetric analysis, Molar concentration, Materials science, Thermal resistance, 0211 other engineering and technologies, 02 engineering and technology, Geopolymer, 021105 building & construction, lcsh:TA401-492, General Materials Science, Composite material, ComputingMilieux_MISCELLANEOUS, Metakaolin, Microstructural analysis, Mechanical Engineering, [CHIM.MATE]Chemical Sciences/Material chemistry, DTA, 021001 nanoscience & nanotechnology, 6. Clean water, Reinforcement, Mechanics of Materials, Dilatometry, lcsh:Materials of engineering and construction. Mechanics of materials, 0210 nano-technology
Abstract

This paper presents results from experimental studies on the thermal resistance and dilatometry analysis of various geopolymer formulations, which were prepared by mixing alkaline solutions, metakaolin and reinforcements. Nine compositions were tested by dilatometric analysis and thermal resistance at high temperature (800 °C). Structural and microstructural analysis was conducted to verify the geopolymerization, and differential thermogravimetric analysis was performed to evaluate the nature of water, depending on the formulation. Some key parameters were identified as critical parameters that influenced the geopolymer properties, such as the nature (Na or K) and the molar concentration of the alkaline cation ([M]

Published
2017

23. Improvement of oxygen flux through perovskite membranes using a coating of ultra-divided particles

Author

Pierre-Marie Geffroy, L. Guironnet, Thierry Chartier, Nicolas Richet, Science des Procédés Céramiques et de Traitements de Surface (SPCTS), Institut des Procédés Appliqués aux Matériaux (IPAM), Université de Limoges (UNILIM)-Université de Limoges (UNILIM)-Ecole Nationale Supérieure de Céramique Industrielle (ENSCI)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Limoges (UNILIM), Agence de l'Environnement et de la Maîtrise de l'Energie (ADEME), Axe 1 : procédés céramiques (SPCTS-AXE1), Université de Limoges (UNILIM)-Université de Limoges (UNILIM)-Ecole Nationale Supérieure de Céramique Industrielle (ENSCI)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Limoges (UNILIM)-Institut des Procédés Appliqués aux Matériaux (IPAM), Centre de Recherche Claude Delorme [Jouy-en-Josas] (CRCD), Air Liquide [Siège Social], Université de Limoges (UNILIM)-Ecole Nationale Supérieure de Céramique Industrielle (ENSCI)-Institut des Procédés Appliqués aux Matériaux (IPAM), Université de Limoges (UNILIM)-Université de Limoges (UNILIM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), and Université de Limoges (UNILIM)-Université de Limoges (UNILIM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Limoges (UNILIM)-Ecole Nationale Supérieure de Céramique Industrielle (ENSCI)-Institut des Procédés Appliqués aux Matériaux (IPAM)

Subjects
Materials science, General Chemical Engineering, Diffusion, Bulk diffusion Coating, Inorganic chemistry, Ionic bonding, chemistry.chemical_element, 02 engineering and technology, engineering.material, 010402 general chemistry, 01 natural sciences, Oxygen, Perovskite ceramic membrane, Mixed conductor, Industrial and Manufacturing Engineering, Coating, Perovskite (structure), Applied Mathematics, Oxygen semi-permeation, Surface exchange mechanism, [CHIM.MATE]Chemical Sciences/Material chemistry, General Chemistry, 021001 nanoscience & nanotechnology, Microstructure, 0104 chemical sciences, Membrane, chemistry, Chemical engineering, Particle-size distribution, engineering, 0210 nano-technology
Abstract

International audience; In the last decades, numerous mixed ionic and electronic conducting materials with a perovskite structure have been investigated for their potential applications as membrane materials for oxygen separation applications. This work shows that significant improvement of electrochemical properties of two perovskite materials, La0.6Sr0.4Fe0.8Co0.2O3-δ (LSFCo6482) and La0.5Sr0.5Fe0.7Ga0.3O3-δ (LSFG5573) is obtained using ultra-divided particles perovskite coating. This coating is obtained by dip-coating thanks to a derived sol-gel synthesis route. The ultra-divided particles have a grain size distribution from 300 to 500 nm. The oxygen flux measured using a specific setup shows that the oxygen surface exchange kinetics and bulk diffusion coefficient depend on the microstructure and the chemical composition of the coating material. The relation established between chemical formulation, microstructure, and oxygen flux were used to design optimized membranes.

Published
2016

24. Characterization of the coupled hygrothermal behavior of unfired clay masonries: Numerical and experimental aspects

Author

Fabrice Gouny, Benoit Nait-Ali, Fazia Fouchal, Dalel Medjelekh, Laurent Ulmet, Frédéric Dubois, Pascal Maillard, Groupe d'Etudes des Matériaux Hétérogènes (GEMH), Université de Limoges (UNILIM)-Institut des Procédés Appliqués aux Matériaux (IPAM), Université de Limoges (UNILIM)-Université de Limoges (UNILIM), Axe 1 : procédés céramiques (SPCTS-AXE1), Science des Procédés Céramiques et de Traitements de Surface (SPCTS), Université de Limoges (UNILIM)-Ecole Nationale Supérieure de Céramique Industrielle (ENSCI)-Institut des Procédés Appliqués aux Matériaux (IPAM), Université de Limoges (UNILIM)-Université de Limoges (UNILIM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Limoges (UNILIM)-Ecole Nationale Supérieure de Céramique Industrielle (ENSCI)-Institut des Procédés Appliqués aux Matériaux (IPAM), and Université de Limoges (UNILIM)-Université de Limoges (UNILIM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Environmental Engineering, Scale (ratio), Moisture, Computer science, business.industry, 020209 energy, Geography, Planning and Development, 0211 other engineering and technologies, Mechanical engineering, Sorption, [CHIM.MATE]Chemical Sciences/Material chemistry, 02 engineering and technology, Building and Construction, Mechanics, Masonry, Finite element method, [SPI.MAT]Engineering Sciences [physics]/Materials, Permeability (earth sciences), Mass transfer, 021105 building & construction, Thermal, 0202 electrical engineering, electronic engineering, information engineering, business, ComputingMilieux_MISCELLANEOUS, Civil and Structural Engineering
Abstract

Numerical and experimental methodologies are presented in order to evaluate thermal and moisture buffering properties of hygroscopic masonry walls composed of unfired clay bricks. An original full-scale instrumented wall is subjected to various transient scenarios on both faces, using a double climatic chamber device. This equipment allows a separated thermodynamic balance in the two rooms for the determination of heat and mass flows through the wall. The development of a coupled heat and mass transfer process implemented in the Cast3M finite element software is outlined as well. The material's input parameters for the model are first identified on samples at a decimeter scale. Among them, a continuous dependence law governing vapor permeability vs. moisture content is established, by exploiting the kinetics of sorption steps in both cubic and half-brick samples. Based on these experimental characterizations, all parameters are introduced for the simulation of a full-scale wall through different scenarios of hydric loading. Comparisons drawn between simulation and the experimental evolutions of moisture and temperature show a good accuracy at this scale. The moisture balance quantities derived in both cells are also verified, proving the model's effectiveness in terms of mass transfer simulation. Finally, the thermal effect of sorption heat is also discussed, experimentally as well as numerically. For realistic scenarios, it is shown to be limited to about 0.5 K.

Published
2016

25. Feasibility of aluminosilicate compounds from various raw materials: Chemical reactivity and mechanical properties

Author

G. Gasgnier, A. Autef, Emmanuel Joussein, Sylvie Rossignol, Science des Procédés Céramiques et de Traitements de Surface (SPCTS), Institut des Procédés Appliqués aux Matériaux (IPAM), Université de Limoges (UNILIM)-Université de Limoges (UNILIM)-Ecole Nationale Supérieure de Céramique Industrielle (ENSCI)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Limoges (UNILIM), Groupement de Recherche Eau, Sol, Environnement (GRESE), Université de Limoges (UNILIM), IMERYS TABLEWARE FRANCE (IMERYS), IMERYS, Axe 3 : organisation structurale multiéchelle des matériaux (SPCTS-AXE3), and Université de Limoges (UNILIM)-Université de Limoges (UNILIM)-Ecole Nationale Supérieure de Céramique Industrielle (ENSCI)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Limoges (UNILIM)-Institut des Procédés Appliqués aux Matériaux (IPAM)

Subjects
010302 applied physics, Materials science, Silicon, General Chemical Engineering, Mineralogy, chemistry.chemical_element, [CHIM.MATE]Chemical Sciences/Material chemistry, 02 engineering and technology, Raw material, 021001 nanoscience & nanotechnology, Microstructure, 01 natural sciences, [SPI.MAT]Engineering Sciences [physics]/Materials, Geopolymer, Chemical engineering, chemistry, Aluminosilicate, Aluminium, 0103 physical sciences, Reactivity (chemistry), 0210 nano-technology, ComputingMilieux_MISCELLANEOUS, Metakaolin
Abstract

International audience; The study of the feasibility of geopolymer formulations was realized from several aluminosilicate sources. Six of them led to the formation of geopolymer-type materials and were confronted with three other reference metakaolins. Several fundamental parameters were identified. A correlation was revealed between these parameters and the reactivity of the mixture, the microstructure and the behavior according to the time of consolidated materials from the various data issues from structural and mechanical characterizations. It has proved possible to predict the behavior of the reactive mixture until its evolution after consolidation for any raw material containing a metakaolinitic phase. All the results allowed to establish a model based on the existence of various geopolymer-type networks: (i) the first one in whom the aluminum atoms participate with the silicon as formers of the network (aluminum-rich) and (ii) the second where the aluminum atoms play the role of compensators in a network rich in silicon.

Published
2016

26. Porosity and insulating properties of silica-fume based foams

Author

Sylvie Rossignol, D. Kpogbemabou, J. Laumonier, Elettra Papa, V. Morinière, Valentina Medri, Angelo Vaccari, Papa, E., Medri, V., Kpogbemabou, D., Morinèere, V., Vaccari, Angelo, Laumonier, J., Rossignol, S., Science des Procédés Céramiques et de Traitements de Surface (SPCTS), Institut des Procédés Appliqués aux Matériaux (IPAM), Université de Limoges (UNILIM)-Université de Limoges (UNILIM)-Ecole Nationale Supérieure de Céramique Industrielle (ENSCI)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Limoges (UNILIM), Institut Pprime (PPRIME), ENSMA-Centre National de la Recherche Scientifique (CNRS)-Université de Poitiers, Axe 3 : organisation structurale multiéchelle des matériaux (SPCTS-AXE3), and Université de Limoges (UNILIM)-Université de Limoges (UNILIM)-Ecole Nationale Supérieure de Céramique Industrielle (ENSCI)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Limoges (UNILIM)-Institut des Procédés Appliqués aux Matériaux (IPAM)

Subjects
Materials science, Hydrogen, Silica fume, Silicon, Alkaline activation, 0211 other engineering and technologies, chemistry.chemical_element, Nanotechnology, 02 engineering and technology, Geopolymer, [SPI.MAT]Engineering Sciences [physics]/Materials, Thermal conductivity, Impurity, 021105 building & construction, Electrical and Electronic Engineering, Porosity, ComputingMilieux_MISCELLANEOUS, Civil and Structural Engineering, Mechanical Engineering, Foams, [CHIM.MATE]Chemical Sciences/Material chemistry, Building and Construction, 021001 nanoscience & nanotechnology, Microstructure, Foam, Insulating materials, chemistry, Chemical engineering, 0210 nano-technology
Abstract

The synthesis of silica-fume based foams, with a multi-range macroporosity, was obtained by alkaline activation. Foams were obtained through an in situ foaming process exploiting the gaseous production of hydrogen caused by the oxidation, in alkaline medium, of metal silicon impurities contained in silica fume. Potassium or sodium alkaline solutions were selected and a temperature of 70 degrees C was sufficient to promote the development of hydrogen bubbles, the increase of the viscosity and the consolidation of the foams. The balance of these reactions allowed to entrap hydrogen bubbles inside the structures creating highly porous foams. The foams were characterized in term of macro- and microstructure, porosity distribution, infrared spectroscopy, thermal and acoustic properties achieved. The foams showed ultramacroporous structures, with a total porosity of approximate to 80%. The average values of bulk density (0.5 g cm(-3)), thermal conductivity (0.16 Wm(-1) K-1), and the acoustic behaviors, highlighted a use of the foams as promising insulating materials. (C) 2016 Elsevier B.V. All rights reserved.

Published
2016

27. Structural studies of Bi2O3-Nb2O5-TeO2 glasses

Author

Morgane Dolhen, Chris J. Benmore, Sébastien Chenu, Paul F. McMillan, Gaëlle Delaizir, Yann Gueguen, Sohei Sukenaga, Martin Wilding, Jean René Duclère, University College of London [London] (UCL), University of Bath [Bath], Axe 3 : organisation structurale multiéchelle des matériaux (SPCTS-AXE3), Science des Procédés Céramiques et de Traitements de Surface (SPCTS), Institut des Procédés Appliqués aux Matériaux (IPAM), Université de Limoges (UNILIM)-Université de Limoges (UNILIM)-Ecole Nationale Supérieure de Céramique Industrielle (ENSCI)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Limoges (UNILIM)-Institut des Procédés Appliqués aux Matériaux (IPAM), Université de Limoges (UNILIM)-Université de Limoges (UNILIM)-Ecole Nationale Supérieure de Céramique Industrielle (ENSCI)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Limoges (UNILIM), Argonne National Laboratory [Lemont] (ANL), Institut de Physique de Rennes (IPR), Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Centre National de la Recherche Scientifique (CNRS), Tohoku University [Sendai], US DOE Argonne National Laboratory [DE-AC02-06CH11357], EPSRC [EP/L017091/1], Université de Limoges (UNILIM)-Ecole Nationale Supérieure de Céramique Industrielle (ENSCI)-Institut des Procédés Appliqués aux Matériaux (IPAM), Université de Limoges (UNILIM)-Université de Limoges (UNILIM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Limoges (UNILIM)-Ecole Nationale Supérieure de Céramique Industrielle (ENSCI)-Institut des Procédés Appliqués aux Matériaux (IPAM), Université de Limoges (UNILIM)-Université de Limoges (UNILIM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), and Université de Rennes (UR)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Phase transition, high-pressure, Materials science, k2o-teo2 glasses, Neutron diffraction, Mineralogy, 02 engineering and technology, system, 010402 general chemistry, 01 natural sciences, law.invention, Annealing (glass), law, Polyamorphism, Materials Chemistry, melting-curve maxima, Crystallization, Supercooling, [PHYS]Physics [physics], Quenching, x-ray-diffraction, neutron-diffraction, tellurite glasses, phase-transitions, polyamorphism, supercooled al2o3-y2o3 liquids, 021001 nanoscience & nanotechnology, Condensed Matter Physics, 0104 chemical sciences, Electronic, Optical and Magnetic Materials, Amorphous solid, Chemical physics, Ceramics and Composites, 0210 nano-technology
Abstract

International audience; Bi2O3-Nb2O5-TeO2 glasses show unusual annealing behavior with appearance of spherulites within the matrix glass structure for the Bi0.5Nb0.5Te3O8 composition. The textures resemble those found previously among polyamorphic Al2O3-Y2O3 glasses containing metastably co-existing high- and low-density phases produced during quenching. However the spherulites produced within the Bi2O3-Nb2O5-TeO2 glass are crystalline and can be identified as an "anti-glass" phase related to beta-Bi2Te4O11. We used high energy synchrotron X-ray diffraction data to study structures of binary and ternary glasses quenched from liquids within the Bi2O3-Nb2O5-TeO2 system. These reveal a glassy network based on interconnected TeO4 and TeO3 units that is related to TeO2 crystalline materials but with larger Te ... Te separations due to the presence of TeO3 groups and non-bridging oxygens linked to modifier (Bi3+, Nb5+) cations. Analysis of the viscosity-temperature relations indicates that the glass-forming liquids are "fragile" and there is no evidence for a LLPT occurring in the supercooled liquid. The glasses obtained by quenching likely correspond to a high-density amorphous (HDA) state. Subsequent annealing above T-g shows mainly evidence for direct crystallization of the "anti-glass" tellurite phase. However, some evidence may exist for simultaneous formation of nanoscale amorphous spherulites that could correspond to the LDA polyamorph. The quenching and annealing behavior of Bi2O3-Nb2O5-TeO2 supercooled liquids and glasses is compared with similar materials in the Al2O3-Y2O3 systeth. (C) 2016 Elsevier B.V. All rights reserved.

Published
2016

28. Elaboration of nanostructured TiO2/SiO2 films by plasma enhanced chemical vapor deposition at atmospheric pressure

Author

Pascal Tristant, Yoan Gazal, Christophe Chazelas, A. Antoine, Christelle Dublanche-Tixier, Maggy Colas, Axe 2 : procédés plasmas et lasers (SPCTS-AXE2), Science des Procédés Céramiques et de Traitements de Surface (SPCTS), Institut des Procédés Appliqués aux Matériaux (IPAM), Université de Limoges (UNILIM)-Université de Limoges (UNILIM)-Ecole Nationale Supérieure de Céramique Industrielle (ENSCI)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Limoges (UNILIM)-Institut des Procédés Appliqués aux Matériaux (IPAM), Université de Limoges (UNILIM)-Université de Limoges (UNILIM)-Ecole Nationale Supérieure de Céramique Industrielle (ENSCI)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Limoges (UNILIM), Axe 3 : organisation structurale multiéchelle des matériaux (SPCTS-AXE3), Université de Limoges (UNILIM)-Ecole Nationale Supérieure de Céramique Industrielle (ENSCI)-Institut des Procédés Appliqués aux Matériaux (IPAM), Université de Limoges (UNILIM)-Université de Limoges (UNILIM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Limoges (UNILIM)-Ecole Nationale Supérieure de Céramique Industrielle (ENSCI)-Institut des Procédés Appliqués aux Matériaux (IPAM), and Université de Limoges (UNILIM)-Université de Limoges (UNILIM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Materials science, Silicon dioxide, Analytical chemistry, 02 engineering and technology, 010402 general chemistry, 01 natural sciences, [SPI.MAT]Engineering Sciences [physics]/Materials, chemistry.chemical_compound, Plasma-enhanced chemical vapor deposition, Materials Chemistry, Thin film, Atmospheric pressure, [SPI.PLASMA]Engineering Sciences [physics]/Plasmas, Metals and Alloys, [CHIM.MATE]Chemical Sciences/Material chemistry, Surfaces and Interfaces, 021001 nanoscience & nanotechnology, Microstructure, Ion source, 0104 chemical sciences, Surfaces, Coatings and Films, Electronic, Optical and Magnetic Materials, Amorphous solid, chemistry, Titanium dioxide, 0210 nano-technology
Abstract

International audience; This paper reports a rapid and simple method for the co-deposition of TiO2/SiO2 films, using a microwave plasma torch and organometallic precursors. Both structure and microstructure of the films have particularly been investigated. The results show that the characteristics of the deposits mainly depend on the torch to substrate distance (d). When this distance is short (d = 10 mm), the co-deposits are quite dense and exhibit crystalline TiO2 phases. By contrast, when d = 30 mm, the co-deposits are amorphous. At d = 30 mm, it was also shown that silica could act as an encapsulation matrix for titania particles in only one step. Moreover, for d = 30 mm, the adjunction of silica, about 40 mol% allows enhancing the adherence of the films, whereas pure titania deposits are not adherent at all.

Published
2016

29. Preparation of C/SiC ceramics using a preceramic polycarbosilane synthesized via hydrosilylation

Author

Alexandra-Raluca Graff, Fabien Bouzat, Sylvie Foucaud, Romain Lucas, Axe 1 : procédés céramiques (SPCTS-AXE1), Science des Procédés Céramiques et de Traitements de Surface (SPCTS), Institut des Procédés Appliqués aux Matériaux (IPAM), Université de Limoges (UNILIM)-Université de Limoges (UNILIM)-Ecole Nationale Supérieure de Céramique Industrielle (ENSCI)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Limoges (UNILIM)-Institut des Procédés Appliqués aux Matériaux (IPAM), Université de Limoges (UNILIM)-Université de Limoges (UNILIM)-Ecole Nationale Supérieure de Céramique Industrielle (ENSCI)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Limoges (UNILIM), and University Polithenica of Bucharest

Subjects
Materials science, Hydrosilylation, chemistry.chemical_element, 02 engineering and technology, 010402 general chemistry, 01 natural sciences, [SPI.MAT]Engineering Sciences [physics]/Materials, law.invention, chemistry.chemical_compound, law, Materials Chemistry, Silicon carbide, Ceramic, Crystallization, Composite material, chemistry.chemical_classification, Silicon Carbide, [CHIM.MATE]Chemical Sciences/Material chemistry, Polymer, 021001 nanoscience & nanotechnology, Polymer precursor, 0104 chemical sciences, High-resolution TEM, chemistry, Chemical engineering, Elemental analysis, visual_art, Ceramics and Composites, visual_art.visual_art_medium, 0210 nano-technology, Carbon, Pyrolysis
Abstract

International audience; This paper deals with the preparation of C/SiC powders via the pyrolysis of a novel polycarbosilane, synthesized by hydrosilylation. The preceramic polymer structure was studied by 1H, 13C and 29Si NMR, and in situ dynamic IR analysis. A pyrolysis up to 1800 °C of this low molecular weight polymer led to β-SiC particles dispersed in a carbon matrix. The excess of free carbon was revealed by elemental analysis and High-Resolution TEM. The ceramization behavior was discussed thanks to TGA/DTA-MS, and XRD analyses. Thus, the crystallization was effective for pyrolysis temperatures above 1200 °C, and the ceramic yield reached a value of 62%. This present study highlights the potential of hydrosilylation to prepare C/SiC powders.

Published
2016

30. Microstructural investigations of NiCrAlY + Y2O3 stabilized ZrO2 cermet coatings deposited by plasma transferred arc (PTA)

Author

Rachida El Ouardi, Alain Denoirjean, Paule Denoirjean, Lech Pawlowski, Camélia Demian, Laboratoire LERMPS (LERMPS), Université de Technologie de Belfort-Montbeliard (UTBM), Axe 2 : procédés plasmas et lasers (SPCTS-AXE2), Science des Procédés Céramiques et de Traitements de Surface (SPCTS), Institut des Procédés Appliqués aux Matériaux (IPAM), Université de Limoges (UNILIM)-Université de Limoges (UNILIM)-Ecole Nationale Supérieure de Céramique Industrielle (ENSCI)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Limoges (UNILIM)-Institut des Procédés Appliqués aux Matériaux (IPAM), Université de Limoges (UNILIM)-Université de Limoges (UNILIM)-Ecole Nationale Supérieure de Céramique Industrielle (ENSCI)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Limoges (UNILIM), Université de Limoges (UNILIM)-Ecole Nationale Supérieure de Céramique Industrielle (ENSCI)-Institut des Procédés Appliqués aux Matériaux (IPAM), Université de Limoges (UNILIM)-Université de Limoges (UNILIM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Limoges (UNILIM)-Ecole Nationale Supérieure de Céramique Industrielle (ENSCI)-Institut des Procédés Appliqués aux Matériaux (IPAM), and Université de Limoges (UNILIM)-Université de Limoges (UNILIM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Materials science, Scanning electron microscope, Composite number, 02 engineering and technology, engineering.material, 01 natural sciences, Indentation hardness, [SPI.MAT]Engineering Sciences [physics]/Materials, Coating, 0103 physical sciences, Materials Chemistry, Cubic zirconia, ComputingMilieux_MISCELLANEOUS, Yttria-stabilized zirconia, 010302 applied physics, Metallurgy, [CHIM.MATE]Chemical Sciences/Material chemistry, Surfaces and Interfaces, General Chemistry, Cermet, 021001 nanoscience & nanotechnology, Condensed Matter Physics, Surfaces, Coatings and Films, engineering, Particle, 0210 nano-technology
Abstract

Plasma transferred arc (PTA) deposition process was applied to develop high temperature protective cermet coatings, metallurgically bonded to the substrate. In this work, yttria-stabilized zirconia (YSZ) filler with two different particle sizes was added into NiCrAlY to develop cermet coatings. Microstructural characterizations using optical and scanning electron microscopes revealed that the addition of 20 vol.% of YSZ modified considerably the morphology of the coating. The formation of tetragonal zirconia, resulting from high temperatures and rapid solidification during surfacing process, was revealed by the X-ray diffraction of the NiCrAlY + 20YSZ composite. The microhardness filiation performed on the composites was influenced by the presence of the YSZ filler particles into the composite coatings.

Published
2016

31. Nonlinear optical studies on 4-(ferrocenylmethylimino)-2-hydroxy-benzoic acid thin films deposited by matrix-assisted pulsed laser evaporation (MAPLE)

Author

Andreea Matei, Iulian Ionita, Bogdana Mitu, Maria Marinescu, Valentin Ion, Maria Dinescu, Catalin Constantinescu, Ana Emandi, Axe 2 : procédés plasmas et lasers (SPCTS-AXE2), Science des Procédés Céramiques et de Traitements de Surface (SPCTS), Institut des Procédés Appliqués aux Matériaux (IPAM), Université de Limoges (UNILIM)-Université de Limoges (UNILIM)-Ecole Nationale Supérieure de Céramique Industrielle (ENSCI)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Limoges (UNILIM)-Institut des Procédés Appliqués aux Matériaux (IPAM), Université de Limoges (UNILIM)-Université de Limoges (UNILIM)-Ecole Nationale Supérieure de Céramique Industrielle (ENSCI)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Limoges (UNILIM), National Institute for Plasma and Radiation Physics (NILPRP), and Centre de recherche

Subjects
Materials science, Analytical chemistry, General Physics and Astronomy, 02 engineering and technology, engineering.material, 010402 general chemistry, 01 natural sciences, [SPI.MAT]Engineering Sciences [physics]/Materials, law.invention, symbols.namesake, law, Thin film, Fourier transform infrared spectroscopy, ComputingMilieux_MISCELLANEOUS, Maple, Second-harmonic generation, [CHIM.MATE]Chemical Sciences/Material chemistry, Surfaces and Interfaces, General Chemistry, 021001 nanoscience & nanotechnology, Condensed Matter Physics, Laser, Evaporation (deposition), 0104 chemical sciences, Surfaces, Coatings and Films, engineering, symbols, 0210 nano-technology, Raman spectroscopy, Refractive index
Abstract

We present results on a new, laboratory synthesized ferrocene-derivative, i.e. 4-(ferrocenylmethylimino)-2-hydroxy-benzoic acid. Thin films with controlled thickness are deposited by matrix-assisted pulsed laser evaporation (MAPLE), on quartz and silicon substrates, with the aim of evaluating the nonlinear optical properties for potential optoelectronic applications. Dimethyl sulfoxide was used as matrix, with 1% wt. concentration of the guest compound. The frozen target is irradiated by using a Nd:YAG laser (4ω/266 nm, 7 ns pulse duration, 10 Hz repetition rate), at low fluences ranging from 0.1 to 1 J/cm2. Atomic force microscopy (AFM) and scanning electron microscopy (SEM) are used to probe the surface morphology of the films. Fourier transform infrared (FTIR) and Raman spectroscopy reveal similar structure of the thin film material when compared to the starting material. The optical properties of the thin films are investigated by spectroscopic-ellipsometry (SE), and the refractive index dependence with respect to temperature is studied. The second harmonic generation (SHG) potential is assessed by using a femtosecond Ti:sapphire laser (800 nm, 60–100 fs pulse duration, 80 MHz repetition rate), at 200 mW maximum output power, revealing that the SHG signal intensity is strongly influenced by the films’ thickness.

Published
2016

32. First-principles study of hydrogen incorporation into the MAX phase Ti 3 AlC 2

Author

Shi Yu, Qing Liu, Xiaoliang Fan, Jinchuan Jie, Nicolas Glandut, Haimin Ding, North China Electric Power University, Axe 2 : procédés plasmas et lasers (SPCTS-AXE2), Science des Procédés Céramiques et de Traitements de Surface (SPCTS), Institut des Procédés Appliqués aux Matériaux (IPAM), Université de Limoges (UNILIM)-Université de Limoges (UNILIM)-Ecole Nationale Supérieure de Céramique Industrielle (ENSCI)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Limoges (UNILIM)-Institut des Procédés Appliqués aux Matériaux (IPAM), Université de Limoges (UNILIM)-Université de Limoges (UNILIM)-Ecole Nationale Supérieure de Céramique Industrielle (ENSCI)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Limoges (UNILIM), Dalian University of Technology, Université de Limoges (UNILIM)-Ecole Nationale Supérieure de Céramique Industrielle (ENSCI)-Institut des Procédés Appliqués aux Matériaux (IPAM), Université de Limoges (UNILIM)-Université de Limoges (UNILIM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Limoges (UNILIM)-Ecole Nationale Supérieure de Céramique Industrielle (ENSCI)-Institut des Procédés Appliqués aux Matériaux (IPAM), and Université de Limoges (UNILIM)-Université de Limoges (UNILIM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Hydrogen, Renewable Energy, Sustainability and the Environment, Chemistry, Diffusion, Energy Engineering and Power Technology, chemistry.chemical_element, [CHIM.MATE]Chemical Sciences/Material chemistry, 02 engineering and technology, 010402 general chemistry, 021001 nanoscience & nanotechnology, Condensed Matter Physics, 01 natural sciences, [SPI.MAT]Engineering Sciences [physics]/Materials, 0104 chemical sciences, Hydrogen storage, Crystallography, Fuel Technology, Octahedron, Phase (matter), Interstitial defect, Atom, 0210 nano-technology, Stoichiometry
Abstract

International audience; First-principles calculations have been performed to study hydrogen incorporation into the MAX phase Ti3AlC2. It is found that H atoms are thermally favorable to be incorporated into the interstitial sites of Ti-Al layers in stoichiometric Ti3AlC2. Only when C vacancies exist, H atoms can be incorporated into Ti-C layers. In Ti-Al layers, the hexagonal interstitial site (Ihexa) consisting of three Al atoms and two Ti atoms, the tetrahedral interstitial site (Itetr-2) consisting of one Al atom and three Ti atoms, and the octahedral interstitial site (Ioct-3) consisting of three Ti atoms and three Al atoms are all possible sites for H incorporation. Among them, Itetr-2 is the most stable one, followed by Ioct-3, and the last one is Ihexa sites. The linear synchronous transit optimization study shows that the diffusion of H in the Ti-Al layers is feasible which could be helpful for the continuous insertion and the following extraction of H in Ti3AlC2.

Published
2016

33. Fast and scalable preparation of tetrahedrite for thermoelectrics via glass crystallization

Author

Annie Pradel, Gaëlle Delaizir, Julie Bourgon, C. Godart, Elsa B. Lopes, Bertrand Lenoir, Andrea Piarristeguy, Jean-Baptiste Vaney, Manuel F. C. Pereira, António Pereira Gonçalves, Eric Alleno, Judith Monnier, Instituto Superior Técnico Universidade de Lisboa (C2TN), Institut de Chimie et des Matériaux Paris-Est (ICMPE), Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC), Institut Jean Lamour (IJL), Institut de Chimie du CNRS (INC)-Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS), Institut Charles Gerhardt Montpellier - Institut de Chimie Moléculaire et des Matériaux de Montpellier (ICGM ICMMM), Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Université Montpellier 1 (UM1)-Université Montpellier 2 - Sciences et Techniques (UM2)-Institut de Chimie du CNRS (INC), Axe 3 : organisation structurale multiéchelle des matériaux (SPCTS-AXE3), Science des Procédés Céramiques et de Traitements de Surface (SPCTS), Institut des Procédés Appliqués aux Matériaux (IPAM), Université de Limoges (UNILIM)-Université de Limoges (UNILIM)-Ecole Nationale Supérieure de Céramique Industrielle (ENSCI)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Limoges (UNILIM)-Institut des Procédés Appliqués aux Matériaux (IPAM), Université de Limoges (UNILIM)-Université de Limoges (UNILIM)-Ecole Nationale Supérieure de Céramique Industrielle (ENSCI)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Limoges (UNILIM), Centro de Recursos Naturais e Ambiente (CERENA), Instituto Superior Técnico, Universidade Técnica de Lisboa (IST), Projet ANR, ANR-11-PRGE-0010,VTG,Verres et vitrocéramiques de chalcogénures en tant que matériaux thermoélectriques pour des applications autour de l'ambiante(2011), Institut de Chimie du CNRS (INC)-Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12)-Centre National de la Recherche Scientifique (CNRS), Institut Charles Gerhardt Montpellier - Institut de Chimie Moléculaire et des Matériaux de Montpellier (ICGM), Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), Université de Limoges (UNILIM)-Ecole Nationale Supérieure de Céramique Industrielle (ENSCI)-Institut des Procédés Appliqués aux Matériaux (IPAM), Université de Limoges (UNILIM)-Université de Limoges (UNILIM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Limoges (UNILIM)-Ecole Nationale Supérieure de Céramique Industrielle (ENSCI)-Institut des Procédés Appliqués aux Matériaux (IPAM), and Université de Limoges (UNILIM)-Université de Limoges (UNILIM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Materials science, Glass ceramics, Analytical chemistry, chemistry.chemical_element, 02 engineering and technology, engineering.material, 010402 general chemistry, 01 natural sciences, law.invention, Bismuth, Antimony, Thermoelectric manufacturing, law, Seebeck coefficient, Materials Chemistry, Crystallization, Waste heat recovery, Mechanical Engineering, Tetrahedrite, Metallurgy, Metals and Alloys, Low-cost thermoelectric materials, 021001 nanoscience & nanotechnology, Thermoelectric materials, Copper, Tetrahedrites, 0104 chemical sciences, chemistry, Mechanics of Materials, [PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], engineering, Melt spinning, 0210 nano-technology
Abstract

A Cu 12 Sb 3.6 Bi 0.4 S 10 Se 3 glass was prepared by melt spinning and crystallized by heat treatments at selected temperatures, the total preparation procedure taking less than one day. The sample characterization by powder X-ray diffraction, scanning and transmission electron microscopy complemented with EDS indicate the formation of compact materials, with a tetrahedrite relative weight fraction higher than 90% when treated at temperatures close to the crystallization peaks (∼200° C). Selenium enters the tetrahedrite structure, while bismuth precipitates in submicron and nanosized spherical shape phases depleted in copper and enriched in antimony, sulfur and selenium (when compared with the matrix composition). The characterization of electrical transport properties (electrical resistivity and Seebeck coefficient) indicate a behavior similar to that obtained by other methods on Cu 12 Sb 4 S 13 , with a maximum power factor of ∼400 μW/K 2 m at room temperature.

Published
2016

34. Influence of Al2O3 incorporation on the third-order nonlinear optical properties of Ag2O–TeO2 glasses

Author

Yusuke Kasuya, K. Kato, Philippe Thomas, Tomokatsu Hayakawa, Nagoya Institute of Technology (NIT), Axe 3 : organisation structurale multiéchelle des matériaux (SPCTS-AXE3), Science des Procédés Céramiques et de Traitements de Surface (SPCTS), Institut des Procédés Appliqués aux Matériaux (IPAM), Université de Limoges (UNILIM)-Université de Limoges (UNILIM)-Ecole Nationale Supérieure de Céramique Industrielle (ENSCI)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Limoges (UNILIM)-Institut des Procédés Appliqués aux Matériaux (IPAM), and Université de Limoges (UNILIM)-Université de Limoges (UNILIM)-Ecole Nationale Supérieure de Céramique Industrielle (ENSCI)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Limoges (UNILIM)

Subjects
Glass structures, Third order nonlinear, Silver, Z-scan, Materials science, Physics::Optics, Mineralogy, 02 engineering and technology, Porous glass, Condensed Matter::Disordered Systems and Neural Networks, 01 natural sciences, [SPI.MAT]Engineering Sciences [physics]/Materials, symbols.namesake, Tellurite, Condensed Matter::Superconductivity, 0103 physical sciences, Thermal, Materials Chemistry, Z-scan technique, Composite material, Crown glass (optics), Raman, 010302 applied physics, Third-order nonlinear susceptibilities, High-refractive-index polymer, Glasses, [CHIM.MATE]Chemical Sciences/Material chemistry, 021001 nanoscience & nanotechnology, Condensed Matter Physics, Electronic, Optical and Magnetic Materials, Condensed Matter::Soft Condensed Matter, Homogeneous, Ceramics and Composites, symbols, 0210 nano-technology, Raman spectroscopy
Abstract

International audience; TeO2-based glasses have been attractive because of their high refractive index and third-order nonlinear optical properties. In general, long melting time is required to obtain the homogeneous glass, but it also leads to enhanced interaction between the crucible and the glass melt. In this study, 20Ag2O–80TeO2 nonlinear optical glasses were fabricated by a melt-quenching method using an alumina or platinum crucible for various melting times. And their thermal characteristics, final glass-compositions, glass structures and linear/nonlinear optical properties were evaluated in order to investigate the influences of the incorporation of Al2O3 in 20Ag2O–80TeO2 glass on third-order nonlinear optical susceptibilities.

Published
2016

35. Effect of the precursor nature and preparation mode on the coarsening of La 2 Zr 2 O 7 compounds

Author

Sylvie Rossignol, William Duarte, Michel Vardelle, Axe 2 : procédés plasmas et lasers (SPCTS-AXE2), Science des Procédés Céramiques et de Traitements de Surface (SPCTS), Institut des Procédés Appliqués aux Matériaux (IPAM), Université de Limoges (UNILIM)-Université de Limoges (UNILIM)-Ecole Nationale Supérieure de Céramique Industrielle (ENSCI)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Limoges (UNILIM)-Institut des Procédés Appliqués aux Matériaux (IPAM), Université de Limoges (UNILIM)-Université de Limoges (UNILIM)-Ecole Nationale Supérieure de Céramique Industrielle (ENSCI)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Limoges (UNILIM), IRCER - Axe 3 : organisation structurale multiéchelle des matériaux (IRCER-AXE3), Institut de Recherche sur les CERamiques (IRCER), Université de Limoges (UNILIM)-Université de Limoges (UNILIM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut des Procédés Appliqués aux Matériaux (IPAM), and Université de Limoges (UNILIM)-Université de Limoges (UNILIM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Materials science, Pyrochlore, chemistry.chemical_element, Mineralogy, 02 engineering and technology, Thermal treatment, engineering.material, 010402 general chemistry, 01 natural sciences, Chloride, Thermal expansion, [SPI.MAT]Engineering Sciences [physics]/Materials, Thermal barrier coating, Phase (matter), Materials Chemistry, medicine, ComputingMilieux_MISCELLANEOUS, Shrinkage, Zirconium, Process Chemistry and Technology, [CHIM.MATE]Chemical Sciences/Material chemistry, 021001 nanoscience & nanotechnology, 0104 chemical sciences, Surfaces, Coatings and Films, Electronic, Optical and Magnetic Materials, chemistry, Chemical engineering, Ceramics and Composites, engineering, 0210 nano-technology, medicine.drug
Abstract

This study addresses the thermal behavior of La 2 Zr 2 O 7 powders prepared via two different synthetic routes and the effect of the zirconium counter-cation on their properties, as carried out by dilatometric experiments. Citrate-based compounds exhibit shrinkage, regardless of the precursors used. Preliminary thermal treatment permits the reduction in shrinkage. Nitrate based compounds calcinated at 600 °C show a higher shrinkage (−9.4%) than at 1200 °C (−5.2%) because of the decomposition of the trapped precursors, as revealed by DTA–TGA–MS. Coprecipitated samples present different behaviors as a function of the counter-cation nature. Chloride based compounds leads to shrinkage and phase mixtures, whereas expansion is observed for pure pyrochlore compounds that are synthesized with nitrate. The thermal expansion coefficients of the different compounds are similar to the literature values (9.5–10.10 −6 K −1 ). This study allowed for a better understanding of the densification of the La 2 Zr 2 O 7 material and its adjusted properties, as a function of the precursor nature and the preparation mode, for application in thermal barrier coatings.

Published
2016

36. Synthesis of destabilized nanostructured lithium hydride via hydrogenation of lithium electrochemically inserted into graphite

Author

Claudia Zlotea, Liwu Huang, Jean-Pierre Bonnet, Michel Latroche, Matthieu Courty, Julie Bourgon, Luc Aymard, Franche-Comté Électronique Mécanique, Thermique et Optique - Sciences et Technologies (UMR 6174) (FEMTO-ST), Université de Technologie de Belfort-Montbeliard (UTBM)-Ecole Nationale Supérieure de Mécanique et des Microtechniques (ENSMM)-Université de Franche-Comté (UFC), Université Bourgogne Franche-Comté [COMUE] (UBFC)-Université Bourgogne Franche-Comté [COMUE] (UBFC)-Centre National de la Recherche Scientifique (CNRS), Groupe d'Etudes des Matériaux Hétérogènes (GEMH), Université de Limoges (UNILIM)-Institut des Procédés Appliqués aux Matériaux (IPAM), Université de Limoges (UNILIM)-Université de Limoges (UNILIM), Institut de Chimie et des Matériaux Paris-Est (ICMPE), Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC), Centre interuniversitaire de recherche et d'ingenierie des matériaux (CIRIMAT), Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC), Laboratoire réactivité et chimie des solides - UMR CNRS 7314 (LRCS), Université de Picardie Jules Verne (UPJV)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC), Université de Franche-Comté (UFC)-Centre National de la Recherche Scientifique (CNRS)-Ecole Nationale Supérieure de Mécanique et des Microtechniques (ENSMM)-Université de Technologie de Belfort-Montbeliard (UTBM), Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12)-Centre National de la Recherche Scientifique (CNRS), Université Fédérale Toulouse Midi-Pyrénées, Laboratoire réactivité et chimie des solides (LRCS), Université de Picardie Jules Verne (UPJV)-Centre National de la Recherche Scientifique (CNRS), Université de Technologie de Belfort-Montbeliard (UTBM)-Ecole Nationale Supérieure de Mécanique et des Microtechniques (ENSMM)-Centre National de la Recherche Scientifique (CNRS)-Université de Franche-Comté (UFC), Université Bourgogne Franche-Comté [COMUE] (UBFC)-Université Bourgogne Franche-Comté [COMUE] (UBFC), Institut de Chimie du CNRS (INC)-Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12)-Centre National de la Recherche Scientifique (CNRS), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), and Université de Picardie Jules Verne (UPJV)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Thermogravimetric analysis, Materials science, Renewable Energy, Sustainability and the Environment, Thermal decomposition, Intercalation (chemistry), Inorganic chemistry, Energy Engineering and Power Technology, chemistry.chemical_element, Condensed Matter Physics, chemistry.chemical_compound, Hydrogen storage, Fuel Technology, chemistry, Lithium hydride, Desorption, [CHIM]Chemical Sciences, Lithium, Graphite, ComputingMilieux_MISCELLANEOUS
Abstract

Lithium hydride-graphite composite is synthesized through hydrogenation of lithium intercalated graphite obtained by electrochemical insertion. XRD analysis indicates that the initial graphite is transformed into a mixture of LiC6 and LiC12 by the intercalation of 0.84 lithium for six carbons. After 20 h of hydrogenation under 30 bars at 150 °C, these lithium-inserted compounds are completely transformed into a lithium hydride-graphite composite based on the reaction: Li0.84C6 + 0.42H2 → 0.84LiH + 6C. A weak shift and broadening of the (002) reflex of graphite is observed after the formation of LiH, which is attributed to a small increase of the graphite disorder. Thermal gravimetric analysis coupled with Mass Spectrometry (TG-MS) shows that the desorption of this synthesized nano-LiH starts from around 200 °C, which is much lower than the decomposition temperature (900 °C) of pure LiH. It reveals that this new electrochemical synthesis process of LiH-graphite composites enables an interesting destabilization of the Li–H ionic bond due to a good dispersion of highly divided LiH nanoparticles (below 100 nm) in a carbon matrix. The hydrogen storage capacity of this LiH-graphite composite can be increased by subsequent Li insertion/hydrogenation cycles.

Published
2015

37. Recycled natural wastes in metakaolin based porous geopolymers for insulating applications

Author

Uphie Chinje Melo, Cristina Leonelli, Zenabou N. M. Ngouloure, S. Zekeng, Elie Kamseu, David S. Smith, Benoît Nait-Ali, University of Yaoundé [Cameroun], Axe 1 : procédés céramiques (SPCTS-AXE1), Science des Procédés Céramiques et de Traitements de Surface (SPCTS), Institut des Procédés Appliqués aux Matériaux (IPAM), Université de Limoges (UNILIM)-Université de Limoges (UNILIM)-Ecole Nationale Supérieure de Céramique Industrielle (ENSCI)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Limoges (UNILIM)-Institut des Procédés Appliqués aux Matériaux (IPAM), Université de Limoges (UNILIM)-Université de Limoges (UNILIM)-Ecole Nationale Supérieure de Céramique Industrielle (ENSCI)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Limoges (UNILIM), and Università degli Studi di Modena e Reggio Emilia (UNIMORE)

Subjects
Materials science, 0211 other engineering and technologies, Rounded pores, 02 engineering and technology, [SPI.MAT]Engineering Sciences [physics]/Materials, Colloid, Thermal conductivity, Thermal insulation, Blowing agent, 021105 building & construction, Architecture, Homogeneity (physics), Composite material, Safety, Risk, Reliability and Quality, Porosity, Chemical composition, ComputingMilieux_MISCELLANEOUS, Metakaolin, Recycled natural waste, Civil and Structural Engineering, Viscosity, business.industry, Colloidal phase, Pore size distribution, Mechanics of Materials, Building and Construction, [CHIM.MATE]Chemical Sciences/Material chemistry, 021001 nanoscience & nanotechnology, 0210 nano-technology, business
Abstract

The effectiveness of two amorphous silica based wastes, rice husk ash and volcanic ash powders, used to act as structural reinforcement and partial replacement of metakaolin in porous matrices for thermal isolation was assessed. Both wastes produced colloidal phase that contributed to improve the reactivity and homogeneity of the matrices enhancing the mechanical strength. Rounded pores were obtained in relation with significant reduction of the interpore partitions under controlled addition of the blowing agent. The bulk thermal conductivity decreased from 0.6 to less than 0.15 W m −1 K −1 with the increase of the concentration of blowing agent. The final matrix presented pore size distribution and pore connectivity that allows analytical description and prediction of their effective thermal conductivity.Results demonstrated that clear relations can be established among the viscosity of the pastes, chemical composition, amount of blowing agent and the volume expansion/pore size distribution.

Published
2015

38. Effect of cation substitution at the B site on the oxygen semi-permeation flux in La 0.5 Ba 0.5 Fe 0.7 B 0.3 O 3−δ dense perovskite membranes with B = Al, Co, Cu, Mg, Mn, Ni, Sn, Ti and Zn (part II)

Author

Mickaël Reichmann, P. Del Gallo, Pierre-Marie Geffroy, J. Fouletier, Thierry Chartier, Nicolas Richet, Axe 1 : procédés céramiques (SPCTS-AXE1), Science des Procédés Céramiques et de Traitements de Surface (SPCTS), Institut des Procédés Appliqués aux Matériaux (IPAM), Université de Limoges (UNILIM)-Université de Limoges (UNILIM)-Ecole Nationale Supérieure de Céramique Industrielle (ENSCI)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Limoges (UNILIM)-Institut des Procédés Appliqués aux Matériaux (IPAM), Université de Limoges (UNILIM)-Université de Limoges (UNILIM)-Ecole Nationale Supérieure de Céramique Industrielle (ENSCI)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Limoges (UNILIM), Laboratoire d'Electrochimie et de Physico-chimie des Matériaux et des Interfaces (LEPMI ), Institut de Chimie du CNRS (INC)-Institut National Polytechnique de Grenoble (INPG)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Université Joseph Fourier - Grenoble 1 (UJF)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS), Centre de Recherche Claude Delorme [Jouy-en-Josas] (CRCD), Air Liquide [Siège Social], and Air Liquide

Subjects
Renewable Energy, Sustainability and the Environment, Inorganic chemistry, Kinetics, Substitution (logic), Oxygen semi-permeation, Energy Engineering and Power Technology, chemistry.chemical_element, [CHIM.MATE]Chemical Sciences/Material chemistry, Permeation, Rate-determining step, Oxygen, Flux (metallurgy), Membrane, chemistry, Oxygen surface exchange, Electrical and Electronic Engineering, Physical and Theoretical Chemistry, Bulk diffusion, Perovskite (structure)
Abstract

International audience; The aim of this paper is to provide insight into the effect of cation substitution at the B site on the oxygen semi-permeation performances. Particular attention is given here to identify the impact of cation substitution at the B site on oxygen diffusion and oxygen surface-exchange kinetics in the La0.5Ba0.5Fe0.7B0.3O3−δ perovskite membrane series with B = Al, Co, Cu, Mg, Mn, Ni, Sn, Ti and Zn.This study clearly shows that the prediction of the oxygen semi-permeation performances of membrane materials from the nature of cation at the A or B sites in perovskite structure is quite complex. The cation substitution at the B-site has a low impact on the nature of rate-determining step and a significant impact on oxygen semi-permeation performances, contrary to the cation substitution at A-site. Unfortunately, it is not possible to establish a relevant trend about the effect of the nature of cation in the A or B sites in perovskite structure on oxygen diffusion and the oxygen surface-exchange kinetics.

Published
2015

39. Cumulative pore volume, pore size distribution and phases percolation in porous inorganic polymer composites: Relation microstructure and effective thermal conductivity

Author

Uphie Chinje Melo, Cristina Leonelli, S. Zekeng, Zenabou N. M. Ngouloure, Sylvie Rossignol, Elie Kamseu, Benoît Nait Ali, Università degli Studi di Modena e Reggio Emilia (UNIMORE), University of Yaoundé [Cameroun], Axe 1 : procédés céramiques (SPCTS-AXE1), Science des Procédés Céramiques et de Traitements de Surface (SPCTS), Institut des Procédés Appliqués aux Matériaux (IPAM), Université de Limoges (UNILIM)-Université de Limoges (UNILIM)-Ecole Nationale Supérieure de Céramique Industrielle (ENSCI)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Limoges (UNILIM)-Institut des Procédés Appliqués aux Matériaux (IPAM), Université de Limoges (UNILIM)-Université de Limoges (UNILIM)-Ecole Nationale Supérieure de Céramique Industrielle (ENSCI)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Limoges (UNILIM), Axe 3 : organisation structurale multiéchelle des matériaux (SPCTS-AXE3), Developing World (TWAS):Grant no.: 11-024 RG/CHE/AF/AC-G, and UNESCO FR:3240262695

Subjects
Inorganic polymer, Materials science, Viscosity, Scanning electron microscope, Mechanical Engineering, Pore shape, [CHIM.MATE]Chemical Sciences/Material chemistry, Building and Construction, Geopolymer, Microstructure, law.invention, Thermal conductivity, Optical microscope, Blowing agent, law, Pore size, Effective thermal conductivity, Civil and Structural Engineering, Electrical and Electronic Engineering, Composite material, Porosity
Abstract

International audience; Rice hush (R) and volcanic (P) ashes, two recycled natural wastes were used for their high amorphous silica to improve the homogeneity and structure composition of inorganic polymer pastes before the expansion with aluminum powder. The fine powders were found to be appropriate in enhancing the geopolymerization and expansion conducting to lightweight structure with pore size and pore distribution linked to the viscosity, the concentration of blowing agent, and the crystalline nature of the waste. From the Stereo optical microscope, environmental scanning microscope and the mercury intrusion porosimetry used for the characterization, it appeared that in the interval of complete percolation of the skeleton, there exists correlation between the viscosity, expansion, roundness of pores, pores size distribution. The interpretation of the microstructure of porous geopolymer in this interval allows the description of their effective thermal conductivity with the Maxwell–Eucken model and the novel effective medium theory proposed recently.

Published
2015

40. Effect of low RF bias potential on AlN films obtained by Microwave Plasma Enhanced Chemical Vapor Deposition

Author

Pascal Tristant, Florent Tetard, Christelle Dublanche-Tixier, Gustavo Sanchez, A. Bologna Alles, Laboratoire des Sciences des Procédés et des Matériaux (LSPM), Université Paris 13 (UP13)-Institut Galilée-Université Sorbonne Paris Cité (USPC)-Centre National de la Recherche Scientifique (CNRS), Groupe d'étude de l'atmosphère météorologique (CNRM-GAME), Institut national des sciences de l'Univers (INSU - CNRS)-Météo France-Centre National de la Recherche Scientifique (CNRS), Axe 2 : procédés plasmas et lasers (SPCTS-AXE2), Science des Procédés Céramiques et de Traitements de Surface (SPCTS), Université de Limoges (UNILIM)-Ecole Nationale Supérieure de Céramique Industrielle (ENSCI)-Institut des Procédés Appliqués aux Matériaux (IPAM), Université de Limoges (UNILIM)-Université de Limoges (UNILIM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Limoges (UNILIM)-Ecole Nationale Supérieure de Céramique Industrielle (ENSCI)-Institut des Procédés Appliqués aux Matériaux (IPAM), Université de Limoges (UNILIM)-Université de Limoges (UNILIM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Faculté Ingenieria, Université Republica, Centre National de la Recherche Scientifique (CNRS)-Université Sorbonne Paris Cité (USPC)-Institut Galilée-Université Paris 13 (UP13), Institut des Procédés Appliqués aux Matériaux (IPAM), Université de Limoges (UNILIM)-Université de Limoges (UNILIM)-Ecole Nationale Supérieure de Céramique Industrielle (ENSCI)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Limoges (UNILIM)-Institut des Procédés Appliqués aux Matériaux (IPAM), and Université de Limoges (UNILIM)-Université de Limoges (UNILIM)-Ecole Nationale Supérieure de Céramique Industrielle (ENSCI)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Limoges (UNILIM)

Subjects
010302 applied physics, Materials science, Analytical chemistry, [CHIM.MATE]Chemical Sciences/Material chemistry, 02 engineering and technology, Surfaces and Interfaces, General Chemistry, Chemical vapor deposition, 021001 nanoscience & nanotechnology, Condensed Matter Physics, Microstructure, 01 natural sciences, Piezoelectricity, Ion source, Surfaces, Coatings and Films, Plasma-enhanced chemical vapor deposition, Residual stress, 0103 physical sciences, Ultimate tensile strength, Materials Chemistry, Crystallite, Composite material, 0210 nano-technology, ComputingMilieux_MISCELLANEOUS
Abstract

AlN films were prepared with a Microwave Plasma Enhanced Chemical Vapor Deposition reactor at 1 Pa and 700 °C using different radiofrequency bias in order to obtain polycrystalline oriented films with minimal residual stresses for piezoelectric applications. The films developed were characterized in term of microstructure, composition and mechanical properties. Crystalline development, exclusive orientation and high tensile residual stresses were observed when the substrate-holder was at the floating potential. A progressive degradation of the crystalline structure was observed with the increase in the negative bias potential, together with the evolution to compressive residual stresses. Simultaneously, significant changes in the microstructure of the surface were observed by atomic force microscopy, as well as in the preferential orientation from to 1 0>. Film properties for piezoelectric applications were optimized with the adequate selection of bias potential.

Published
2014

41. High temperature compressive creep of spark plasma sintered zirconium (oxy-)carbide

Author

Gilles Trolliard, Guy Antou, Alexandre Maitre, Etienne Laborde, Mathieu Gendre, Science des Procédés Céramiques et de Traitements de Surface (SPCTS), Institut des Procédés Appliqués aux Matériaux (IPAM), Université de Limoges (UNILIM)-Université de Limoges (UNILIM)-Ecole Nationale Supérieure de Céramique Industrielle (ENSCI)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Limoges (UNILIM), Axe 1 : procédés céramiques, Université de Limoges (UNILIM)-Ecole Nationale Supérieure de Céramique Industrielle (ENSCI)-Institut des Procédés Appliqués aux Matériaux (IPAM), Université de Limoges (UNILIM)-Université de Limoges (UNILIM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Limoges (UNILIM)-Ecole Nationale Supérieure de Céramique Industrielle (ENSCI)-Institut des Procédés Appliqués aux Matériaux (IPAM), Université de Limoges (UNILIM)-Université de Limoges (UNILIM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Axe 3 : organisation structurale multiéchelle des matériaux (SPCTS-AXE3), and Université de Limoges (UNILIM)-Université de Limoges (UNILIM)-Ecole Nationale Supérieure de Céramique Industrielle (ENSCI)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Limoges (UNILIM)-Institut des Procédés Appliqués aux Matériaux (IPAM)

Subjects
Zirconium, Materials science, Mechanical Engineering, Diffusion, Spark plasma sintering, chemistry.chemical_element, Sintering, Mineralogy, [CHIM.MATE]Chemical Sciences/Material chemistry, Condensed Matter Physics, Microstructure, Carbide, chemistry, Creep, Mechanics of Materials, General Materials Science, Composite material, ComputingMilieux_MISCELLANEOUS, Stoichiometry
Abstract

The effect of stoichiometry ( i.e . carbon and oxygen contents) and microstructure ( i.e . micro-sized grains) on creep mechanism of zirconium oxycarbide was considered. The synthesis of ZrC x O y powder of controlled stoichiometry and without impurity has been performed via the carboreduction route. Compressive creep experiments were conducted at 1500–1600 °C under applied stresses ranging from 60 to 140 MPa on fully dense zirconium oxycarbide specimens obtained by spark plasma sintering. The higher oxygen content composition ( i.e . ZrC 0.79 O 0.13 ) reveals low creep resistance in contrary to ZrC 0.94 O 0.05 composition. The analysis of the creep data shows the existence of a linear creep limit ( σ t ). At low stress ( i.e. σ ≤ σ t = 1 00 MPa, n ≈1, m ≈1), the creep mechanism seems to be independent of the chemical composition, and is governed by zirconium volume diffusion. At high stress ( i.e. σ≥σ t =100 MPa, n ≈3, m ≈0), a power law regime of creep appears. However, the nature of the rate-determining step of creep process depends on stoichiometry. The limiting species for volume diffusion are (i) the metal atom for ZrC 0.94 O 0.05 ; (ii) and the carbon atom for ZrC 0.79 O 0.13 linked to a Rowcliffe dislocation diffusion mechanism.

Published
2014

42. Mechanical, thermal and acoustical characterizations of an insulating bio-based composite made from sunflower stalks particles and chitosan

Author

Philippe Michaud, Shengnan Sun, Narimane Mati-Baouche, Carlos Javier Sacristan Lopez-Mingo, Hélène de Baynast, André Lebert, P. Leclaire, Institut Pascal ( IP ), Université Blaise Pascal - Clermont-Ferrand 2 ( UBP ) -Sigma CLERMONT ( Sigma CLERMONT ) -Centre National de la Recherche Scientifique ( CNRS ), Département de Recherche en Ingéniérie des Véhicules pour l'Environnement ( DRIVE ), Université de Bourgogne ( UB ), Institut Pascal (IP), Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-SIGMA Clermont (SIGMA Clermont)-Centre National de la Recherche Scientifique (CNRS), Département de Recherche en Ingéniérie des Véhicules pour l'Environnement (DRIVE), Université de Bourgogne (UB), Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Sigma CLERMONT (Sigma CLERMONT)-Centre National de la Recherche Scientifique (CNRS), Institut Pascal - Clermont Auvergne (IP), Sigma CLERMONT (Sigma CLERMONT)-Université Clermont Auvergne (UCA)-Centre National de la Recherche Scientifique (CNRS), Groupe d'Etudes des Matériaux Hétérogènes (GEMH), Université de Limoges (UNILIM)-Institut des Procédés Appliqués aux Matériaux (IPAM), and Université de Limoges (UNILIM)-Université de Limoges (UNILIM)

Subjects
Absorption (acoustics), Materials science, 020209 energy, Composite number, Compaction, Young's modulus, 02 engineering and technology, Chitosan, Stress (mechanics), [SPI]Engineering Sciences [physics], chemistry.chemical_compound, symbols.namesake, Thermal conductivity, Thermal, 0202 electrical engineering, electronic engineering, information engineering, Young modulus, [INFO]Computer Science [cs], Composite material, [SPI.ACOU]Engineering Sciences [physics]/Acoustics [physics.class-ph], [ SPI.ACOU ] Engineering Sciences [physics]/Acoustics [physics.class-ph], 021001 nanoscience & nanotechnology, Sunflower, Bio-based composite, chemistry, symbols, 0210 nano-technology, Agronomy and Crop Science
Abstract

International audience; This study has for objective the determination of thermal, mechanical and acoustical properties of insulating bio-based composite made with chitosan and sunflower's stalks particles. An experimental design was established to find the size grading of particles, the ratio chitosan/sunflower particles and the stress of compaction influencing the thermal and mechanical properties. Composites with a thermal conductivity $(\kappa)$ of 0.056 W/m/K, a maximum stress $(\sigma_{\text{max}})$ of 2 MPa and an acoustic coefficient of absorption $(\alpha)$ of 0.2 were obtained with a ratio of chitosan of 4.3% (w/w) and a size grading of particles higher to 3 mm. These mechanical and thermal performances are competitive with those of other insulating bio-based materials available on the market.

Published
2014

43. Extraction and fractionation of polysaccharides and B-phycoerythrin from the microalga Porphyridium cruentum by membrane technology

Author

Sébastien Jubeau, Alain Marcati, Luc Marchal, Céline Laroche, Nastasia Soanen, Gholamreza Djelveh, Philippe Michaud, Alina-Violeta Ursu, Institut Pascal (IP), Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Sigma CLERMONT (Sigma CLERMONT)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de génie des procédés - environnement - agroalimentaire (GEPEA), Université de Nantes (UN)-Ecole Nationale Vétérinaire, Agroalimentaire et de l'alimentation Nantes-Atlantique (ONIRIS)-Centre National de la Recherche Scientifique (CNRS)-Université Bretagne Loire (UBL)-IMT Atlantique Bretagne-Pays de la Loire (IMT Atlantique), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT), Algosource Technologies, SIGMA Clermont (SIGMA Clermont)-Centre National de la Recherche Scientifique (CNRS)-Université Clermont Auvergne [2017-2020] (UCA [2017-2020]), Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-SIGMA Clermont (SIGMA Clermont)-Centre National de la Recherche Scientifique (CNRS), Bioprocédés Appliqués aux Microalgues (GEPEA-BAM), Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST), Université de Nantes (UN)-Université de Nantes (UN)-IMT Atlantique Bretagne-Pays de la Loire (IMT Atlantique), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT)-Centre National de la Recherche Scientifique (CNRS)-Ecole Polytechnique de l'Université de Nantes (EPUN), Université de Nantes (UN)-Université de Nantes (UN)-Institut Universitaire de Technologie - Nantes (IUT Nantes), Université de Nantes (UN)-Institut Universitaire de Technologie Saint-Nazaire (IUT Saint-Nazaire), Université de Nantes (UN)-Institut Universitaire de Technologie - La Roche-sur-Yon (IUT La Roche-sur-Yon), Université de Nantes (UN)-Ecole Nationale Vétérinaire, Agroalimentaire et de l'alimentation Nantes-Atlantique (ONIRIS)-Université Bretagne Loire (UBL)-Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST), Université de Nantes (UN)-Ecole Nationale Vétérinaire, Agroalimentaire et de l'alimentation Nantes-Atlantique (ONIRIS)-Université Bretagne Loire (UBL), Groupe d'Etudes des Matériaux Hétérogènes (GEMH), Université de Limoges (UNILIM)-Institut des Procédés Appliqués aux Matériaux (IPAM), Université de Limoges (UNILIM)-Université de Limoges (UNILIM), SIGMA Clermont (SIGMA Clermont)-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Centre National de la Recherche Scientifique (CNRS), Institut Universitaire de Technologie - Nantes (IUT Nantes), Université de Nantes (UN)-Université de Nantes (UN)-Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST), Université de Nantes (UN)-Université de Nantes (UN)-Institut Universitaire de Technologie Saint-Nazaire (IUT Saint-Nazaire), Université de Nantes (UN)-Ecole Polytechnique de l'Université de Nantes (EPUN), Université de Nantes (UN)-École nationale vétérinaire, agroalimentaire et de l'alimentation Nantes-Atlantique (ONIRIS)-Centre National de la Recherche Scientifique (CNRS)-Université Bretagne Loire (UBL)-IMT Atlantique (IMT Atlantique), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT)-Institut Universitaire de Technologie - La Roche-sur-Yon (IUT La Roche-sur-Yon), Université de Nantes (UN)-Institut Universitaire de Technologie - Nantes (IUT Nantes), and Université de Nantes (UN)

Subjects
0106 biological sciences, [SDV.BIO]Life Sciences [q-bio]/Biotechnology, Ultrafiltration, Fractionation, Biology, Polysaccharide, 01 natural sciences, Membrane technology, [SPI]Engineering Sciences [physics], 03 medical and health sciences, 010608 biotechnology, [SPI.GPROC]Engineering Sciences [physics]/Chemical and Process Engineering, ComputingMilieux_MISCELLANEOUS, 030304 developmental biology, chemistry.chemical_classification, 0303 health sciences, Chromatography, Extraction (chemistry), biology.organism_classification, 6. Clean water, [SDV.BBM.BC]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Biomolecules [q-bio.BM], Membrane, chemistry, Porphyridium cruentum, Porphyridium, Agronomy and Crop Science
Abstract

Porphyridium species are exploited for the production of exopolysaccharides and B-phycoerythrin, two high-value compounds. Extraction and purification of these two substances often involve antagonistic processes (precipitation with ethanol, isoelectric precipitation, aqueous two-phase systems, chromatography and ultrafiltration) that work better for one than for the other. We developed a two-step membrane process using polyethersulfone flat membranes with a filtration surface of 0.1 m2 to recover both B-phycoerythrin and soluble polysaccharides from Porphyridium biomass with high polysaccharide content. A first ultrafiltration at 300,000 yielded high molecular weight polysaccharides. The resulting 300,000 permeate was then run through a second, 10,000 membrane to recover BPE. This procedure enabled us to extract 48% of B-phycoerythrin free of polysaccharide with a purity index of 2.3.

Published
2014

44. Dispersion of phyllosilicates in aqueous suspensions: Role of the nature and amount of surfactant

Author

Nadia Houta, Gisèle Laure Lecomte-Nana, Nicolas Tessier-Doyen, Claire Peyratout, Groupe d'Etudes des Matériaux Hétérogènes (GEMH), Université de Limoges (UNILIM)-Institut des Procédés Appliqués aux Matériaux (IPAM), and Université de Limoges (UNILIM)-Université de Limoges (UNILIM)

Subjects
Aqueous solution, Inorganic chemistry, Surface charge, Sodium silicate, Zeta potential, [CHIM.MATE]Chemical Sciences/Material chemistry, Dispersion, engineering.material, Halloysite, Dispersant, Surfaces, Coatings and Films, Electronic, Optical and Magnetic Materials, Biomaterials, chemistry.chemical_compound, Sodium hexametaphosphate, Colloid and Surface Chemistry, chemistry, Rheology, Phyllosilicate, engineering, Sodium carbonate
Abstract

Hypotheses The present work aims at investigating the effect of pH values and additives on the dispersion of two 1:1 dioctahedral phyllosilicates in the presence of water. Two model clays are used for this purpose, BIP kaolin and NZCC halloysite, presenting the same surface chemistry but different morphologies. The effect of sodium hexametaphosphate, sodium silicate and sodium carbonate is discussed. Experiments Kaolin and halloysite powders were first characterized using X-ray diffraction, thermogravimetric analysis and scanning electron microscopy. Subsequently, suspensions containing 8 mass% of each clay were prepared with or without additives. Experimental measurements regarding the pH values, the zeta potential and the rheological behavior were performed to determine the most suitable additive. Findings Results show that the conformation of halloysite particles changes regarding pH values of suspensions and is strongly related to the surface charges of these particles. At their natural pH values, halloysite and kaolin suspensions exhibit zeta potentials equal to −50 and −20 mV respectively. This trend indicates that halloysite-based suspensions are well dispersed compared to kaolin-based suspensions. Sodium hexametaphosphate is the most suitable dispersant for both clays. The rheological characterization regarding further applications in casting process indicates a shear-thinning behavior for all studied compositions.

Published
2014

45. Calcium aluminate cement tapes – Part II: Physical properties

Author

Jean-Pierre Bonnet, L. Nibou, Y. El Hafiane, Thierry Chartier, Y. Abouliatim, Agnès Smith, Ecole Nationale des Sciences Appliquées [Safi] (ENSA), Groupe d'Etudes des Matériaux Hétérogènes (GEMH), Université de Limoges (UNILIM)-Institut des Procédés Appliqués aux Matériaux (IPAM), Université de Limoges (UNILIM)-Université de Limoges (UNILIM), Axe 1 : procédés céramiques, Science des Procédés Céramiques et de Traitements de Surface (SPCTS), Université de Limoges (UNILIM)-Ecole Nationale Supérieure de Céramique Industrielle (ENSCI)-Institut des Procédés Appliqués aux Matériaux (IPAM), Université de Limoges (UNILIM)-Université de Limoges (UNILIM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Limoges (UNILIM)-Ecole Nationale Supérieure de Céramique Industrielle (ENSCI)-Institut des Procédés Appliqués aux Matériaux (IPAM), and Université de Limoges (UNILIM)-Université de Limoges (UNILIM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Tape casting, Cement, Physical properties, Materials science, business.industry, Aluminate, Hydration, Humidity, [CHIM.MATE]Chemical Sciences/Material chemistry, Dielectric, chemistry.chemical_compound, chemistry, 13. Climate action, Materials Chemistry, Ceramics and Composites, Surface roughness, Microelectronics, Relative humidity, Composite material, Aluminous cement, business, Films
Abstract

International audience; Tape casting is a process often used for the preparation of microelectronics substrates. The present work is a continuation of the first part where we have discussed the structural and microstructural characteristics of calcium aluminate cement tape. Indeed, in this second part, we focus on the physical properties of these tapes such as electrical, thermal, mechanical characterizations and surface roughness. We studied in particular how these physical properties vary according to the setting environment (water, air at 50% relative humidity or air saturated in humidity), setting time (1 day, 4 days or 1 month) and setting temperature (20 °C or 70 °C in the case of water setting environment). A Heat treatment on the consolidated tape was made essentially to decrease the dielectric constant. Following our results and comparing the physical properties with those of substrates commonly used in microelectronics, in particular alumina substrates, our films can be potentially used as microelectronics substrate.

Published
2014

46. Structural and microstructural studies of montmorillonite-based multilayer nanocomposites

Author

Alain Jacquet, Claire Peyratout, Le Chien Hoang, Fayza Gridi-Bennadji, Agnès Smith, Serge Ghilardi, David Kpogbémabou, Groupe d'Etudes des Matériaux Hétérogènes (GEMH), Université de Limoges (UNILIM)-Institut des Procédés Appliqués aux Matériaux (IPAM), Université de Limoges (UNILIM)-Université de Limoges (UNILIM), and Lafarge Centre de Recherche

Subjects
Thermogravimetric analysis, Materials science, Composite number, Molecular Conformation, Dispersant, Nanocomposites, Phosphates, Biomaterials, chemistry.chemical_compound, Sodium hexametaphosphate, Colloid and Surface Chemistry, Hardness, Materials Testing, Intercalation, Exfoliation, Particle Size, Chitosan, Nanocomposite, [CHIM.MATE]Chemical Sciences/Material chemistry, Interface, Microstructure, Exfoliation joint, Surfaces, Coatings and Films, Electronic, Optical and Magnetic Materials, Surface, Montmorillonite, chemistry, Chemical engineering, Carboxymethylcellulose Sodium, Thermogravimetry, Bentonite, Microscopy, Electron, Scanning, Clay, Adsorption, Rheology, Natural polymers
Abstract

Hypotheses Montmorillonite, an abundant raw material, is a good candidate to obtain textured nanocomposites. However, the resulting structure of the composite depends on the dispersant used. This work aims at investigating the effect of organic polysaccharides, namely carboxymethylcellulose (CMC) or chitosan (Ch) differing by their side groups, on the resulting structure of montmorillonite-based nanocomposites. Experiments The effect of sodium hexametaphosphate and of two polysaccharide derivatives (carboxymethylcellulose and chitosan) combined with montmorillonite on the structure and microstructure of resulting composite films was investigated using particle size analysis, rheological measurements, thermogravimetric analysis, X-ray diffraction, scanning electron microscopy and flexural properties measurements of the textured films. Findings Results showed that the film structure and microstructure depend on the additive. The high organization (and resulting toughness) of the montmorillonite/sodium hexametaphosphate films results from an exfoliated then layered microstructure, whereas the addition of polysaccharide derivatives leads to the particle agglomeration. In this case, two mechanisms are in competition: surface adsorption and intercalation between exfoliated platelets.

Published
2014

47. Role of metakaolin dehydroxylation in geopolymer synthesis

Author

Emmanuel Joussein, Gilles Gasgnier, Stéphane Pronier, A. Autef, Jesús Sanz, Isabella Sobrados, Sylvie Rossignol, European Commission, Groupe d'Etudes des Matériaux Hétérogènes (GEMH), Université de Limoges (UNILIM)-Institut des Procédés Appliqués aux Matériaux (IPAM), Université de Limoges (UNILIM)-Université de Limoges (UNILIM), Groupement de Recherche Eau, Sol, Environnement (GRESE), Université de Limoges (UNILIM), IMERYS TABLEWARE FRANCE (IMERYS), IMERYS, Institut de Chimie des Milieux et Matériaux de Poitiers (IC2MP), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Poitiers-Institut de Chimie du CNRS (INC), Instituto de Ciencia de Materiales de Madrid (ICMM), Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), Axe 3 : organisation structurale multiéchelle des matériaux (SPCTS-AXE3), Science des Procédés Céramiques et de Traitements de Surface (SPCTS), Université de Limoges (UNILIM)-Ecole Nationale Supérieure de Céramique Industrielle (ENSCI)-Institut des Procédés Appliqués aux Matériaux (IPAM), Université de Limoges (UNILIM)-Université de Limoges (UNILIM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Limoges (UNILIM)-Ecole Nationale Supérieure de Céramique Industrielle (ENSCI)-Institut des Procédés Appliqués aux Matériaux (IPAM), and Université de Limoges (UNILIM)-Université de Limoges (UNILIM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Materials science, General Chemical Engineering, 0211 other engineering and technologies, Dehydroxylation, Mineralogy, 02 engineering and technology, Geopolymer, law.invention, law, Impurity, Kaolinite, Differential thermal analysis, 021105 building & construction, Calcination, Fourier transform infrared spectroscopy, Metakaolin, Prima materia, Reactivity, [CHIM.MATE]Chemical Sciences/Material chemistry, 021001 nanoscience & nanotechnology, Metakaolinite, Raw material, Chemical engineering, 0210 nano-technology
Abstract

The properties and structures of three commercial metakaolins were evaluated for their use in geopolymer materials. The dehydroxylation processes used on these three metakaolins (rotary, flash or oven processes) induce varying reactivities and purities according to the results obtained by FTIR spectroscopy, XRD, 27Al MAS-NMR, TEM characterization, and DTA. The flash-calcined metakaolin is the most reactive one. After geopolymerization, the impurities (such as quartz or micas) and the reactivities of the raw metakaolins induce the formation of different networks within the geopolymer material. This study demonstrates the main role of the metakaolin dehydroxylation process, the effect of impurities and the use of the wettability as an indicator of metakaolin reactivity. © 2013 Elsevier B.V., The authors thank the Limousin FEDER for financing this study. This work was scientifically supported by the Scientific Interest Groupment “Groupement d'Intéret Scientifique GIS” G3.

Published
2013

48. Fabrication and characterization of U1−Am O2± compounds with high americium contents (x= 0.3, 0.4 and 0.5)

Author

Philippe Blanchart, Florent Lebreton, Thibaud Delahaye, Denis Horlait, Département de recherche sur les procédés pour la mine et le recyclage du combustible (DMRC), CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Groupe d'Etudes des Matériaux Hétérogènes (GEMH), Université de Limoges (UNILIM)-Institut des Procédés Appliqués aux Matériaux (IPAM), and Université de Limoges (UNILIM)-Université de Limoges (UNILIM)

Subjects
Diffraction, Nuclear and High Energy Physics, Fabrication, Materials science, Nuclear transmutation, chemistry.chemical_element, Americium, Context (language use), 02 engineering and technology, 010402 general chemistry, 01 natural sciences, [CHIM.CRIS]Chemical Sciences/Cristallography, General Materials Science, Neutron, ComputingMilieux_MISCELLANEOUS, Phase diagram, Radiochemistry, [CHIM.MATE]Chemical Sciences/Material chemistry, 021001 nanoscience & nanotechnology, 0104 chemical sciences, Characterization (materials science), Nuclear Energy and Engineering, chemistry, [PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], Physical chemistry, 0210 nano-technology
Abstract

Mixed uranium–americium oxides are considered promising compounds for americium transmutation in fast neutron reactors. A better understanding of these materials and of the U–Am–O phase diagram is, however, needed. Though many results in the literature describe U1−xAmxO2±δ (x ⩽ 0.2) compounds, very few studies concern higher Am contents. In this context, this article reports the fabrication method of U1−xAmxO2±δ (0.3 ⩽ x ⩽ 0.5) and their preliminary characterization, notably by X-ray diffraction.

Published
2013

49. Effect of the pore volume fraction on the thermal conductivity and mechanical properties of kaolin-based foams

Author

Fabienne Pennec, B. Nait-Ali, Arnaud Alzina, Nicolas Tessier-Doyen, David S. Smith, Julie Bourret, Claire Peyratout, Groupe d'Etudes des Matériaux Hétérogènes (GEMH), Université de Limoges (UNILIM)-Institut des Procédés Appliqués aux Matériaux (IPAM), Université de Limoges (UNILIM)-Université de Limoges (UNILIM), and Limousin Region for financial support

Subjects
Materials science, Modulus, Mechanical properties, 02 engineering and technology, 01 natural sciences, Thermal conductivity, Thermal insulation, 0103 physical sciences, Materials Chemistry, Kaolinite, Composite material, Porosity, 010302 applied physics, Consolidation (soil), business.industry, [CHIM.MATE]Chemical Sciences/Material chemistry, 021001 nanoscience & nanotechnology, Microstructure, Foam, Volume fraction, Ceramics and Composites, Clay, 0210 nano-technology, business
Abstract

Candidate materials for thermal insulation combine a solid phase of low thermal conductivity with porosity. Very porous ceramics based on a commercial clay containing 79% kaolinite were made by a direct foaming method using methylcellulose, drying at 70 °C before a consolidation at 1100 °C. The pore volume fraction ( v p ) was varied in the kaolin-based foam by modifying the amount of clay incorporated in the starting mixture. Measurements of the thermal conductivity with the hot disk method revealed a decrease from 0.23 W m−1 K−1 at v p = 0.57 to 0.054 W m−1 K−1 at v p = 0.95 in close agreement to predictions by the Hashin–Shtrikman upper bound, a cubic pore model and numerical simulation of an artificial microstructure representing the polyhedral pore shape with Voronoi mosaics. The effective Young's modulus, obtained from mechanical compression tests, also decreases with pore volume fraction as described by Ashby's relation. However the mechanical strength was sufficient for handling even the more porous kaolin-based foams.

Published
2013

50. Kaolin-based geopolymers: Effect of mechanical activation and curing process

Author

Gnande Djeteli, Ayi Djifa Hounsi, Philippe Blanchart, Gisèle Laure Lecomte-Nana, Groupe d'Etudes des Matériaux Hétérogènes (GEMH), Université de Limoges (UNILIM)-Institut des Procédés Appliqués aux Matériaux (IPAM), and Université de Limoges (UNILIM)-Université de Limoges (UNILIM)

Subjects
Materials science, Geopolymers, Compressive strength105, 0211 other engineering and technologies, [CHIM.MATE]Chemical Sciences/Material chemistry, 02 engineering and technology, Building and Construction, 021001 nanoscience & nanotechnology, Mechanical activation, Curing time, Compressive strength, Aluminosilicate, 021105 building & construction, General Materials Science, Composite material, Kaolin, 0210 nano-technology, Curing (chemistry), Civil and Structural Engineering
Abstract

International audience; The present work aimed to investigate the influence of mechanical activation of raw kaolin on the final compressive strength of as-obtained geopolymers regarding the curing profile. A commercial raw kaolin containing 81.5 mass% of kaolin (labeled KBip) was used. Mechanical activation was performed by dry ball-milling of raw kaolin at 250 rpm for 1 h. The curing temperatures were 40 °C, 70 °C or 100 °C for 24 h, 48 h or 72 h. The compressive tests were conducted on geopolymers after the 2nd, 7th, 14th and 28th days of ageing. Mechanical activation was performed to improve mechanical properties. Results showed that without mechanical activation, the optimal curing condition was 24 h at 70 °C and the compressive strength was 15 MPa after 28 days of ageing. Under mechanical activation, improvement of the compressive strength was obtained with a curing time of 72 h at 70 °C (to reach 35% increase) or with a curing temperature of 100 °C (for 76% improvement). The formation of alkaline aluminosilicate gels and new crystalline hydrated phases controlled the strength development of geopolymers while the occurrence of carbonated species was responsible for the degradation of mechanical properties.

Published
2013

Catalog

Books, media, physical & digital resources
See catalog results