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Papers by F. Gouttefangeas

Research paper thumbnail of Coupling of SEM-EDX and FTIR-ATR to (quantitatively) investigate organic fouling on porous organic composite membranes

Membrane processes are widely used at industrial scale for separation/concentration purpose. Amon... more Membrane processes are widely used at industrial scale for separation/concentration purpose. Among filtered fluids are tape water and food fluids, both containing biological components. For this later case the most used membranes are composite organic materials made of three layers that are consecutively crossed by the filtered fluid. The main drawback of membrane processes is the built-up , in the course of the filtration, of a more or less thick fouling layer that can be located both in/on the membrane. As both fouling components and membrane are organic compounds, a specific approach is proposed in this chapter to be able to distinguish carbon, nitrogen and oxygen issued from the membrane and the fouling layer, respectively, by using a post-treatment of raw SEM-EDX results. The methodology is detailed in the case of ultrafiltration membrane made of PES fouled with skim milk , a complex media leading to membrane fouling mainly made of proteins. A complementary analysis is achieved...

Research paper thumbnail of Coupling of SEM-EDX and FTIR-ATR to (quantitatively) investigate organic fouling on porous organic composite membranes

Membrane processes are widely used at industrial scale for separation/concentration purpose. Amon... more Membrane processes are widely used at industrial scale for separation/concentration purpose. Among filtered fluids are tape water and food fluids, both containing biological components. For this later case the most used membranes are composite organic materials made of three layers that are consecutively crossed by the filtered fluid. The main drawback of membrane processes is the built-up , in the course of the filtration, of a more or less thick fouling layer that can be located both in/on the membrane. As both fouling components and membrane are organic compounds, a specific approach is proposed in this chapter to be able to distinguish carbon, nitrogen and oxygen issued from the membrane and the fouling layer, respectively, by using a post-treatment of raw SEM-EDX results. The methodology is detailed in the case of ultrafiltration membrane made of PES fouled with skim milk , a complex media leading to membrane fouling mainly made of proteins. A complementary analysis is achieved...

Research paper thumbnail of Experimental investigation of the U–Zr–Al ternary phase diagram: Isothermal sections at 673K and 1073K

Journal of Nuclear Materials, 2015

ABSTRACT Isothermal sections at 673 K and 1073 K of the ternary U–Zr–Al system were established i... more ABSTRACT Isothermal sections at 673 K and 1073 K of the ternary U–Zr–Al system were established in the whole concentration range, by means of powder X-ray diffraction, scanning electron microscopy–energy dispersive X-ray spectroscopy and differential thermal analysis. All measured compositions and unit-cell refinements were performed at room temperature from quenched samples annealed at 1073 K and 673 K for four and eight weeks respectively. For both temperatures, the Al-rich corner of the phase diagram is characterized by extended homogeneity ranges due to mutual exchange between U and Zr in UAl3 (cubic, AuCu3-type) and in the Laves phase UAl2 (cubic, MgCu2-type). Minute U solubility in ZrAl2 (hexagonal, MgZn2-type) and in Zr2Al (hexagonal, Ni2In-type) was evaluated to be of the order of 1 at.% U. For the other binary compounds, the solubility of the third component was found negligible. At 1073 K, the solid solution based on γU (cubic, W-type) which covers the U–Zr binary axis up to 95.5 at.% Zr, allows also some limited solubility of Al [maximum of 5 at.%]. For Al-content below 66 at.%, most of the phase relations comprise equilibria between the Zr–Al binaries and the γ(U,Zr,Al) solid solution. At 673 K, the U–Zr axis is found in agreement with the literature data and no Al solubility could be detected in αU, αZr and UZr2 (δ phase). The phase relations are mainly established between Zr–Al binaries and αU. For monolithic UMo fuel with a Zr diffusion barrier foil cladded with Al, the main interaction product is expected to involve the U-based alloy with the Zr–Al binary compounds and the pseudo-binary U1−xZrxAl2 and U1−xZrxAl3 phases.

Research paper thumbnail of Experimental investigation of the U–Zr–Al ternary phase diagram: Isothermal sections at 673K and 1073K

Journal of Nuclear Materials, 2015

ABSTRACT Isothermal sections at 673 K and 1073 K of the ternary U–Zr–Al system were established i... more ABSTRACT Isothermal sections at 673 K and 1073 K of the ternary U–Zr–Al system were established in the whole concentration range, by means of powder X-ray diffraction, scanning electron microscopy–energy dispersive X-ray spectroscopy and differential thermal analysis. All measured compositions and unit-cell refinements were performed at room temperature from quenched samples annealed at 1073 K and 673 K for four and eight weeks respectively. For both temperatures, the Al-rich corner of the phase diagram is characterized by extended homogeneity ranges due to mutual exchange between U and Zr in UAl3 (cubic, AuCu3-type) and in the Laves phase UAl2 (cubic, MgCu2-type). Minute U solubility in ZrAl2 (hexagonal, MgZn2-type) and in Zr2Al (hexagonal, Ni2In-type) was evaluated to be of the order of 1 at.% U. For the other binary compounds, the solubility of the third component was found negligible. At 1073 K, the solid solution based on γU (cubic, W-type) which covers the U–Zr binary axis up to 95.5 at.% Zr, allows also some limited solubility of Al [maximum of 5 at.%]. For Al-content below 66 at.%, most of the phase relations comprise equilibria between the Zr–Al binaries and the γ(U,Zr,Al) solid solution. At 673 K, the U–Zr axis is found in agreement with the literature data and no Al solubility could be detected in αU, αZr and UZr2 (δ phase). The phase relations are mainly established between Zr–Al binaries and αU. For monolithic UMo fuel with a Zr diffusion barrier foil cladded with Al, the main interaction product is expected to involve the U-based alloy with the Zr–Al binary compounds and the pseudo-binary U1−xZrxAl2 and U1−xZrxAl3 phases.

Research paper thumbnail of Reinvestigation of the Ce–Co–Al ternary system: Isothermal section at 973K

Journal of Alloys and Compounds, 2015

ABSTRACT The Ce–Co–Al ternary phase diagram has been reinvestigated at 973 K by means of powder X... more ABSTRACT The Ce–Co–Al ternary phase diagram has been reinvestigated at 973 K by means of powder X-ray diffraction, scanning electron microscopy, energy dispersive spectroscopy and differential thermal analyses. It contains 5 ternary phases (CeCo2Al8, Ce2Co6Al19, CeCoAl4, Ce3Co3Al4 and CeCoAl) as well as 7 extensions in the ternary field of pseudo-binaries (CeAl2−xCox with 0 ⩽ x ⩽ 0.18; CeCo2−xAlx with 0 ⩽ x ⩽ 0.21; CeCo3−yAly with 0 ⩽ y ⩽ 0.20; Ce2Co7−xAlx with 0 ⩽ x ⩽ 0.73; Ce5Co19−yAly with 0 ⩽ y ⩽ 0.20; CeCo5−xAlx with 0 ⩽ x ⩽ 0.71 and Ce2Co17−yAly with 0 ⩽ y ⩽ 2.2). Two liquid areas are present at the Al and Ce-rich corners of this isothermal section.

Research paper thumbnail of Reinvestigation of the Ce–Co–Al ternary system: Isothermal section at 973K

Journal of Alloys and Compounds, 2015

ABSTRACT The Ce–Co–Al ternary phase diagram has been reinvestigated at 973 K by means of powder X... more ABSTRACT The Ce–Co–Al ternary phase diagram has been reinvestigated at 973 K by means of powder X-ray diffraction, scanning electron microscopy, energy dispersive spectroscopy and differential thermal analyses. It contains 5 ternary phases (CeCo2Al8, Ce2Co6Al19, CeCoAl4, Ce3Co3Al4 and CeCoAl) as well as 7 extensions in the ternary field of pseudo-binaries (CeAl2−xCox with 0 ⩽ x ⩽ 0.18; CeCo2−xAlx with 0 ⩽ x ⩽ 0.21; CeCo3−yAly with 0 ⩽ y ⩽ 0.20; Ce2Co7−xAlx with 0 ⩽ x ⩽ 0.73; Ce5Co19−yAly with 0 ⩽ y ⩽ 0.20; CeCo5−xAlx with 0 ⩽ x ⩽ 0.71 and Ce2Co17−yAly with 0 ⩽ y ⩽ 2.2). Two liquid areas are present at the Al and Ce-rich corners of this isothermal section.

Research paper thumbnail of Ionic and electronic conductivity of 3mol% Fe2O3-substituted cubic Y-stabilized ZrO2

Research paper thumbnail of Ionic and electronic conductivity of 3mol% Fe2O3-substituted cubic Y-stabilized ZrO2

Research paper thumbnail of Intrinsic magnetic properties of BixCo2−xMnO4 spinels obtained by short-time etching

Journal of Magnetism and Magnetic Materials, 2013

ABSTRACT We report the structural and magnetic properties of Co2MnO4, partially substituted by Bi... more ABSTRACT We report the structural and magnetic properties of Co2MnO4, partially substituted by Bi at the octahedral site. Bismuth enhances ferromagnetism due to a decrease of the Co2+–Co2+ antiferromagnetic interactions and an increase of the Mn3+–Mn4+ exchanges. Spurious phases (magnetic and/or nonmagnetic oxides) can easily form because of the large differences between the ionic radii of Bi3+ and Co3+, hiding or altering the intrinsic physical properties of the main BixCo2−xMnO4 phase. An easy way to eliminate the secondary phases is using acid reagents. Short-time etching of Bi0.1Co1.9MnO4 using nitric acid was successfully used, keeping most of the properties of the initial compound, with no alteration of the crystallographic structure. Final stoichiometry was respected (∼Bi0.08Co1.82MnO4), meaning that the material after etching definitely contains bismuth elements in its structure and the observed properties are intrinsic to the oxide spinel. Additional experiments were performed as a function of the synthesis conditions, showing that an optimal pH value of 7 allowed the best magnetic response of the non-doped material.

Research paper thumbnail of Intrinsic magnetic properties of BixCo2−xMnO4 spinels obtained by short-time etching

Journal of Magnetism and Magnetic Materials, 2013

ABSTRACT We report the structural and magnetic properties of Co2MnO4, partially substituted by Bi... more ABSTRACT We report the structural and magnetic properties of Co2MnO4, partially substituted by Bi at the octahedral site. Bismuth enhances ferromagnetism due to a decrease of the Co2+–Co2+ antiferromagnetic interactions and an increase of the Mn3+–Mn4+ exchanges. Spurious phases (magnetic and/or nonmagnetic oxides) can easily form because of the large differences between the ionic radii of Bi3+ and Co3+, hiding or altering the intrinsic physical properties of the main BixCo2−xMnO4 phase. An easy way to eliminate the secondary phases is using acid reagents. Short-time etching of Bi0.1Co1.9MnO4 using nitric acid was successfully used, keeping most of the properties of the initial compound, with no alteration of the crystallographic structure. Final stoichiometry was respected (∼Bi0.08Co1.82MnO4), meaning that the material after etching definitely contains bismuth elements in its structure and the observed properties are intrinsic to the oxide spinel. Additional experiments were performed as a function of the synthesis conditions, showing that an optimal pH value of 7 allowed the best magnetic response of the non-doped material.

Research paper thumbnail of Adhérence fibre d’acier–matrice cimentaire dans les mortiers fibrés à hautes températures

Research paper thumbnail of Coupling of SEM-EDX and FTIR-ATR to (quantitatively) investigate organic fouling on porous organic composite membranes

Membrane processes are widely used at industrial scale for separation/concentration purpose. Amon... more Membrane processes are widely used at industrial scale for separation/concentration purpose. Among filtered fluids are tape water and food fluids, both containing biological components. For this later case the most used membranes are composite organic materials made of three layers that are consecutively crossed by the filtered fluid. The main drawback of membrane processes is the built-up , in the course of the filtration, of a more or less thick fouling layer that can be located both in/on the membrane. As both fouling components and membrane are organic compounds, a specific approach is proposed in this chapter to be able to distinguish carbon, nitrogen and oxygen issued from the membrane and the fouling layer, respectively, by using a post-treatment of raw SEM-EDX results. The methodology is detailed in the case of ultrafiltration membrane made of PES fouled with skim milk , a complex media leading to membrane fouling mainly made of proteins. A complementary analysis is achieved...

Research paper thumbnail of Coupling of SEM-EDX and FTIR-ATR to (quantitatively) investigate organic fouling on porous organic composite membranes

Membrane processes are widely used at industrial scale for separation/concentration purpose. Amon... more Membrane processes are widely used at industrial scale for separation/concentration purpose. Among filtered fluids are tape water and food fluids, both containing biological components. For this later case the most used membranes are composite organic materials made of three layers that are consecutively crossed by the filtered fluid. The main drawback of membrane processes is the built-up , in the course of the filtration, of a more or less thick fouling layer that can be located both in/on the membrane. As both fouling components and membrane are organic compounds, a specific approach is proposed in this chapter to be able to distinguish carbon, nitrogen and oxygen issued from the membrane and the fouling layer, respectively, by using a post-treatment of raw SEM-EDX results. The methodology is detailed in the case of ultrafiltration membrane made of PES fouled with skim milk , a complex media leading to membrane fouling mainly made of proteins. A complementary analysis is achieved...

Research paper thumbnail of Experimental investigation of the U–Zr–Al ternary phase diagram: Isothermal sections at 673K and 1073K

Journal of Nuclear Materials, 2015

ABSTRACT Isothermal sections at 673 K and 1073 K of the ternary U–Zr–Al system were established i... more ABSTRACT Isothermal sections at 673 K and 1073 K of the ternary U–Zr–Al system were established in the whole concentration range, by means of powder X-ray diffraction, scanning electron microscopy–energy dispersive X-ray spectroscopy and differential thermal analysis. All measured compositions and unit-cell refinements were performed at room temperature from quenched samples annealed at 1073 K and 673 K for four and eight weeks respectively. For both temperatures, the Al-rich corner of the phase diagram is characterized by extended homogeneity ranges due to mutual exchange between U and Zr in UAl3 (cubic, AuCu3-type) and in the Laves phase UAl2 (cubic, MgCu2-type). Minute U solubility in ZrAl2 (hexagonal, MgZn2-type) and in Zr2Al (hexagonal, Ni2In-type) was evaluated to be of the order of 1 at.% U. For the other binary compounds, the solubility of the third component was found negligible. At 1073 K, the solid solution based on γU (cubic, W-type) which covers the U–Zr binary axis up to 95.5 at.% Zr, allows also some limited solubility of Al [maximum of 5 at.%]. For Al-content below 66 at.%, most of the phase relations comprise equilibria between the Zr–Al binaries and the γ(U,Zr,Al) solid solution. At 673 K, the U–Zr axis is found in agreement with the literature data and no Al solubility could be detected in αU, αZr and UZr2 (δ phase). The phase relations are mainly established between Zr–Al binaries and αU. For monolithic UMo fuel with a Zr diffusion barrier foil cladded with Al, the main interaction product is expected to involve the U-based alloy with the Zr–Al binary compounds and the pseudo-binary U1−xZrxAl2 and U1−xZrxAl3 phases.

Research paper thumbnail of Experimental investigation of the U–Zr–Al ternary phase diagram: Isothermal sections at 673K and 1073K

Journal of Nuclear Materials, 2015

ABSTRACT Isothermal sections at 673 K and 1073 K of the ternary U–Zr–Al system were established i... more ABSTRACT Isothermal sections at 673 K and 1073 K of the ternary U–Zr–Al system were established in the whole concentration range, by means of powder X-ray diffraction, scanning electron microscopy–energy dispersive X-ray spectroscopy and differential thermal analysis. All measured compositions and unit-cell refinements were performed at room temperature from quenched samples annealed at 1073 K and 673 K for four and eight weeks respectively. For both temperatures, the Al-rich corner of the phase diagram is characterized by extended homogeneity ranges due to mutual exchange between U and Zr in UAl3 (cubic, AuCu3-type) and in the Laves phase UAl2 (cubic, MgCu2-type). Minute U solubility in ZrAl2 (hexagonal, MgZn2-type) and in Zr2Al (hexagonal, Ni2In-type) was evaluated to be of the order of 1 at.% U. For the other binary compounds, the solubility of the third component was found negligible. At 1073 K, the solid solution based on γU (cubic, W-type) which covers the U–Zr binary axis up to 95.5 at.% Zr, allows also some limited solubility of Al [maximum of 5 at.%]. For Al-content below 66 at.%, most of the phase relations comprise equilibria between the Zr–Al binaries and the γ(U,Zr,Al) solid solution. At 673 K, the U–Zr axis is found in agreement with the literature data and no Al solubility could be detected in αU, αZr and UZr2 (δ phase). The phase relations are mainly established between Zr–Al binaries and αU. For monolithic UMo fuel with a Zr diffusion barrier foil cladded with Al, the main interaction product is expected to involve the U-based alloy with the Zr–Al binary compounds and the pseudo-binary U1−xZrxAl2 and U1−xZrxAl3 phases.

Research paper thumbnail of Reinvestigation of the Ce–Co–Al ternary system: Isothermal section at 973K

Journal of Alloys and Compounds, 2015

ABSTRACT The Ce–Co–Al ternary phase diagram has been reinvestigated at 973 K by means of powder X... more ABSTRACT The Ce–Co–Al ternary phase diagram has been reinvestigated at 973 K by means of powder X-ray diffraction, scanning electron microscopy, energy dispersive spectroscopy and differential thermal analyses. It contains 5 ternary phases (CeCo2Al8, Ce2Co6Al19, CeCoAl4, Ce3Co3Al4 and CeCoAl) as well as 7 extensions in the ternary field of pseudo-binaries (CeAl2−xCox with 0 ⩽ x ⩽ 0.18; CeCo2−xAlx with 0 ⩽ x ⩽ 0.21; CeCo3−yAly with 0 ⩽ y ⩽ 0.20; Ce2Co7−xAlx with 0 ⩽ x ⩽ 0.73; Ce5Co19−yAly with 0 ⩽ y ⩽ 0.20; CeCo5−xAlx with 0 ⩽ x ⩽ 0.71 and Ce2Co17−yAly with 0 ⩽ y ⩽ 2.2). Two liquid areas are present at the Al and Ce-rich corners of this isothermal section.

Research paper thumbnail of Reinvestigation of the Ce–Co–Al ternary system: Isothermal section at 973K

Journal of Alloys and Compounds, 2015

ABSTRACT The Ce–Co–Al ternary phase diagram has been reinvestigated at 973 K by means of powder X... more ABSTRACT The Ce–Co–Al ternary phase diagram has been reinvestigated at 973 K by means of powder X-ray diffraction, scanning electron microscopy, energy dispersive spectroscopy and differential thermal analyses. It contains 5 ternary phases (CeCo2Al8, Ce2Co6Al19, CeCoAl4, Ce3Co3Al4 and CeCoAl) as well as 7 extensions in the ternary field of pseudo-binaries (CeAl2−xCox with 0 ⩽ x ⩽ 0.18; CeCo2−xAlx with 0 ⩽ x ⩽ 0.21; CeCo3−yAly with 0 ⩽ y ⩽ 0.20; Ce2Co7−xAlx with 0 ⩽ x ⩽ 0.73; Ce5Co19−yAly with 0 ⩽ y ⩽ 0.20; CeCo5−xAlx with 0 ⩽ x ⩽ 0.71 and Ce2Co17−yAly with 0 ⩽ y ⩽ 2.2). Two liquid areas are present at the Al and Ce-rich corners of this isothermal section.

Research paper thumbnail of Ionic and electronic conductivity of 3mol% Fe2O3-substituted cubic Y-stabilized ZrO2

Research paper thumbnail of Ionic and electronic conductivity of 3mol% Fe2O3-substituted cubic Y-stabilized ZrO2

Research paper thumbnail of Intrinsic magnetic properties of BixCo2−xMnO4 spinels obtained by short-time etching

Journal of Magnetism and Magnetic Materials, 2013

ABSTRACT We report the structural and magnetic properties of Co2MnO4, partially substituted by Bi... more ABSTRACT We report the structural and magnetic properties of Co2MnO4, partially substituted by Bi at the octahedral site. Bismuth enhances ferromagnetism due to a decrease of the Co2+–Co2+ antiferromagnetic interactions and an increase of the Mn3+–Mn4+ exchanges. Spurious phases (magnetic and/or nonmagnetic oxides) can easily form because of the large differences between the ionic radii of Bi3+ and Co3+, hiding or altering the intrinsic physical properties of the main BixCo2−xMnO4 phase. An easy way to eliminate the secondary phases is using acid reagents. Short-time etching of Bi0.1Co1.9MnO4 using nitric acid was successfully used, keeping most of the properties of the initial compound, with no alteration of the crystallographic structure. Final stoichiometry was respected (∼Bi0.08Co1.82MnO4), meaning that the material after etching definitely contains bismuth elements in its structure and the observed properties are intrinsic to the oxide spinel. Additional experiments were performed as a function of the synthesis conditions, showing that an optimal pH value of 7 allowed the best magnetic response of the non-doped material.

Research paper thumbnail of Intrinsic magnetic properties of BixCo2−xMnO4 spinels obtained by short-time etching

Journal of Magnetism and Magnetic Materials, 2013

ABSTRACT We report the structural and magnetic properties of Co2MnO4, partially substituted by Bi... more ABSTRACT We report the structural and magnetic properties of Co2MnO4, partially substituted by Bi at the octahedral site. Bismuth enhances ferromagnetism due to a decrease of the Co2+–Co2+ antiferromagnetic interactions and an increase of the Mn3+–Mn4+ exchanges. Spurious phases (magnetic and/or nonmagnetic oxides) can easily form because of the large differences between the ionic radii of Bi3+ and Co3+, hiding or altering the intrinsic physical properties of the main BixCo2−xMnO4 phase. An easy way to eliminate the secondary phases is using acid reagents. Short-time etching of Bi0.1Co1.9MnO4 using nitric acid was successfully used, keeping most of the properties of the initial compound, with no alteration of the crystallographic structure. Final stoichiometry was respected (∼Bi0.08Co1.82MnO4), meaning that the material after etching definitely contains bismuth elements in its structure and the observed properties are intrinsic to the oxide spinel. Additional experiments were performed as a function of the synthesis conditions, showing that an optimal pH value of 7 allowed the best magnetic response of the non-doped material.

Research paper thumbnail of Adhérence fibre d’acier–matrice cimentaire dans les mortiers fibrés à hautes températures