The Experts below are selected from a list of 291 Experts worldwide ranked by ideXlab platform
D. Stuerga - One of the best experts on this subject based on the ideXlab platform.
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Novel Metallic Iron/manganese-zinc ferrite nanocomposites prepared by microwave hydrothermal flash synthesis
Journal of Alloys and Compounds, 2011Co-Authors: T. Caillot, G. Pourroy, D. StuergaAbstract:Metallic Iron (alpha-Fe)/manganese-zinc ferrite (Fe3-x-yMnxZnyO4) nanocomposites have been successfully synthesized for the first time using microwave hydrothermal treatment of alcoholic solutions of chloride precursors and sodium ethoxide. This new type of nanocomposites, never obtained by conventional synthesis, can now be produced in a short period (e.g. 15s). The powders were characterized by X-ray diffraction, transmission electron microscopy and magnetic properties were measured. In most cases, three classes of crystallites were observed; one of them is composed of grains of about 100 nm in size where the metal is inserted into the oxide. For all samples, 20% of Metallic Iron was routinely obtained using the microwave flash synthesis. Consequently, the microwave heating appears to provide an efficient source of energy in producing Metallic Iron nanoparticles protected against oxidation by an oxide matrix. (c) 2010 Elsevier B.V. All rights reserved.
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Novel Metallic Iron/manganese–zinc ferrite nanocomposites prepared by microwave hydrothermal flash synthesis
Journal of Alloys and Compounds, 2011Co-Authors: T. Caillot, G. Pourroy, D. StuergaAbstract:Abstract Metallic Iron (α-Fe)/manganese–zinc ferrite (Fe 3− x − y Mn x Zn y O 4 ) nanocomposites have been successfully synthesized for the first time using microwave hydrothermal treatment of alcoholic solutions of chloride precursors and sodium ethoxide. This new type of nanocomposites, never obtained by conventional synthesis, can now be produced in a short period (e.g. 15 s). The powders were characterized by X-ray diffraction, transmission electron microscopy and magnetic properties were measured. In most cases, three classes of crystallites were observed; one of them is composed of grains of about 100 nm in size where the metal is inserted into the oxide. For all samples, 20% of Metallic Iron was routinely obtained using the microwave flash synthesis. Consequently, the microwave heating appears to provide an efficient source of energy in producing Metallic Iron nanoparticles protected against oxidation by an oxide matrix.
T. Caillot - One of the best experts on this subject based on the ideXlab platform.
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Novel Metallic Iron/manganese-zinc ferrite nanocomposites prepared by microwave hydrothermal flash synthesis
Journal of Alloys and Compounds, 2011Co-Authors: T. Caillot, G. Pourroy, D. StuergaAbstract:Metallic Iron (alpha-Fe)/manganese-zinc ferrite (Fe3-x-yMnxZnyO4) nanocomposites have been successfully synthesized for the first time using microwave hydrothermal treatment of alcoholic solutions of chloride precursors and sodium ethoxide. This new type of nanocomposites, never obtained by conventional synthesis, can now be produced in a short period (e.g. 15s). The powders were characterized by X-ray diffraction, transmission electron microscopy and magnetic properties were measured. In most cases, three classes of crystallites were observed; one of them is composed of grains of about 100 nm in size where the metal is inserted into the oxide. For all samples, 20% of Metallic Iron was routinely obtained using the microwave flash synthesis. Consequently, the microwave heating appears to provide an efficient source of energy in producing Metallic Iron nanoparticles protected against oxidation by an oxide matrix. (c) 2010 Elsevier B.V. All rights reserved.
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Novel Metallic Iron/manganese–zinc ferrite nanocomposites prepared by microwave hydrothermal flash synthesis
Journal of Alloys and Compounds, 2011Co-Authors: T. Caillot, G. Pourroy, D. StuergaAbstract:Abstract Metallic Iron (α-Fe)/manganese–zinc ferrite (Fe 3− x − y Mn x Zn y O 4 ) nanocomposites have been successfully synthesized for the first time using microwave hydrothermal treatment of alcoholic solutions of chloride precursors and sodium ethoxide. This new type of nanocomposites, never obtained by conventional synthesis, can now be produced in a short period (e.g. 15 s). The powders were characterized by X-ray diffraction, transmission electron microscopy and magnetic properties were measured. In most cases, three classes of crystallites were observed; one of them is composed of grains of about 100 nm in size where the metal is inserted into the oxide. For all samples, 20% of Metallic Iron was routinely obtained using the microwave flash synthesis. Consequently, the microwave heating appears to provide an efficient source of energy in producing Metallic Iron nanoparticles protected against oxidation by an oxide matrix.
Chicgoua Noubactep - One of the best experts on this subject based on the ideXlab platform.
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Metallic Iron for envIronmental remediation: the long walk to evidence
Corrosion Reviews, 2013Co-Authors: Chicgoua NoubactepAbstract:The science of Metallic Iron for envIronmental remediation is yet to be established. The prevailing theory of the Fe 0 /H 2 O system is characterized by its inability to fully rationalize the concept that holds up the technology. The present article demonstrates that Fe 0 technology was introduced by altering the course of mainstream science and by distorting the work of corrosion scientists. The Fe 0 research community is now facing the consequences of this initial " forcing " . The technology is still innovative despite two decades of commercialization.
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Metallic Iron for Water Treatment: A Critical Review
CLEAN - Soil Air Water, 2013Co-Authors: Chicgoua NoubactepAbstract:Water treatment with Metallic Iron (Fe0) is still based on the premise that Fe0 is a reducing agent. An alternative concept stipulates that contaminants are removed by adsorption, co-precipitation, and size-exclusion in a reactive filtration process. This article underlines the universal validity of the alternative concept. It is shown that admixing non-expansive material to Fe0 as a pre-requisite for sustainable Fe0-based filtration systems. Fe0-based filters are demonstrated an affordable, appropriate, and efficient decentralized water treatment technology.
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On the mechanism of microbe inactivation by Metallic Iron.
Journal of hazardous materials, 2011Co-Authors: Chicgoua NoubactepAbstract:Abstract This letter challenges the concept that the Metallic Iron (Fe 0 ) surface contributes directly to the process of micro-organism inactivation in aqueous solutions. It is shown that any antimicrobial properties of Fe 0 is related to the cycle of expansion/contraction accompanying aqueous Iron corrosion. This demonstration corroborates the concept that aqueous contaminant removal in the presence of Fe 0 mostly occurs at the Fe-oxide/water interface or within the oxide-film on Fe 0 .
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On nanoscale Metallic Iron for groundwater remediation.
Journal of Hazardous Materials, 2010Co-Authors: Chicgoua Noubactep, Sabine CaréAbstract:This communication challenges the concept that nanoscale Metallic Iron (nano-Fe0) is a strong reducing agents for contaminant reductive transformation. It is shown that the inherent relationship between contaminant removal and Fe0 oxidative dissolution which is conventionally attributed to contaminant reduction by nano-Fe0 (direct reduction) could equally be attributed to contaminant removal by adsorption and co-precipitation. For reducible contaminants, indirect reduction by adsorbed FeII or adsorbed H produced by corroding Iron (indirect reduction) is even a more probable reaction path. As a result, the contaminant removal efficiency is strongly dependent on the extent of Iron corrosion which is larger for nano-Fe0 than for micro-Fe0 in the short term. However, because of the increased reactivity, nano-Fe0 will deplete in the short term. No more source of reducing agents (FeII, H and H2) will be available in the system. Therefore, the efficiency of nano-Fe0 as a reducing agent for envIronmental remediation is yet to be demonstrated.
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The suitability of Metallic Iron for envIronmental remediation
Environmental Progress & Sustainable Energy, 2009Co-Authors: Chicgoua NoubactepAbstract:Aqueous contaminant removal in the presence of Metallic Iron is often regarded as a reductive transformation mediated by the Fe0 surface. However, successful removal of theoretically nonreducible contaminants has been largely reported. This article presents a rebuttal of the concept of contaminant reductive transformation. It is argued through a careful examination of the evolution of the volume and adsorptive properties of Iron and its corrosion products that contaminants are primarily adsorbed and coprecipitated with Iron corrosion products. One may wonder how the Fe0 technology will develop with the new concept. © 2009 American Institute of Chemical Engineers EnvIron Prog, 2010
Jorge R. Frade - One of the best experts on this subject based on the ideXlab platform.
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Reduction of magnetite to Metallic Iron in strong alkaline medium
Electrochimica Acta, 2016Co-Authors: J.f. Monteiro, Yu. A. Ivanova, Andrei V. Kovalevsky, D.k. Ivanou, Jorge R. FradeAbstract:Abstract This work focuses on assessing the feasibility of cathodic Iron extraction from the magnetite based precursors. For this, electrochemical processes at Fe 3 O 4 /alkaline electrolyte interface were screened by cycling voltammetry. Based on these results, one obtained guidelines for selecting the conditions (i.e., potential and temperature) where efficient direct electrochemical reduction of magnetite ceramics to Metallic Iron occurs. Electrochemical conversion of relatively dense magnetite samples yields a polycrystalline Fe scale, formed at the surface of the magnetite pellet in direct contact with the bulk electrolyte. Still, the onset of slightly open porosity results in formation of intermediate layers with coexisting magnetite and Metallic Fe; this is ascribed to gradual development of additional porosity, which promotes sample impregnation with the electrolyte, extends the effective electrochemically active area, and facilitates dissolution of soluble species in the inner pores. This is clearly demonstrated by transient response behavior, with remarkable increase in the current density. The key roles of porosity and effective Fe 3 O 4 /electrolyte area are also emphasized by the enhanced kinetics of electrochemical reduction observed for highly porous magnetite samples, with nearly homogeneous distribution of reactant (Fe 3 O 4 ) and product (Metallic Fe), without a clear surface scale of Metallic Iron. In this case, the final product is very porous and fragile. The conversion of highly porous magnetite samples also proceeds with much higher Faradaic efficiency compared to nearly dense ceramics.
G. Pourroy - One of the best experts on this subject based on the ideXlab platform.
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Novel Metallic Iron/manganese-zinc ferrite nanocomposites prepared by microwave hydrothermal flash synthesis
Journal of Alloys and Compounds, 2011Co-Authors: T. Caillot, G. Pourroy, D. StuergaAbstract:Metallic Iron (alpha-Fe)/manganese-zinc ferrite (Fe3-x-yMnxZnyO4) nanocomposites have been successfully synthesized for the first time using microwave hydrothermal treatment of alcoholic solutions of chloride precursors and sodium ethoxide. This new type of nanocomposites, never obtained by conventional synthesis, can now be produced in a short period (e.g. 15s). The powders were characterized by X-ray diffraction, transmission electron microscopy and magnetic properties were measured. In most cases, three classes of crystallites were observed; one of them is composed of grains of about 100 nm in size where the metal is inserted into the oxide. For all samples, 20% of Metallic Iron was routinely obtained using the microwave flash synthesis. Consequently, the microwave heating appears to provide an efficient source of energy in producing Metallic Iron nanoparticles protected against oxidation by an oxide matrix. (c) 2010 Elsevier B.V. All rights reserved.
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Novel Metallic Iron/manganese–zinc ferrite nanocomposites prepared by microwave hydrothermal flash synthesis
Journal of Alloys and Compounds, 2011Co-Authors: T. Caillot, G. Pourroy, D. StuergaAbstract:Abstract Metallic Iron (α-Fe)/manganese–zinc ferrite (Fe 3− x − y Mn x Zn y O 4 ) nanocomposites have been successfully synthesized for the first time using microwave hydrothermal treatment of alcoholic solutions of chloride precursors and sodium ethoxide. This new type of nanocomposites, never obtained by conventional synthesis, can now be produced in a short period (e.g. 15 s). The powders were characterized by X-ray diffraction, transmission electron microscopy and magnetic properties were measured. In most cases, three classes of crystallites were observed; one of them is composed of grains of about 100 nm in size where the metal is inserted into the oxide. For all samples, 20% of Metallic Iron was routinely obtained using the microwave flash synthesis. Consequently, the microwave heating appears to provide an efficient source of energy in producing Metallic Iron nanoparticles protected against oxidation by an oxide matrix.
