Dissertations / Theses on the topic 'Synthèse en sel fondu'
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Bermis, Philippe. "Synthèse en sel fondu de poudres d'YBa2Cu3O(7-x) et application à l'élaboration de céramiques supraconductrices texturées." Grenoble INPG, 1991. http://www.theses.fr/1991INPG0111.
Vigier, Jean-François. "Synthèse d’oxydes d’actinides en milieu chlorure fondu : études structurales et mécanismes réactionnels." Electronic Thesis or Diss., Lille 1, 2012. http://www.theses.fr/2012LIL10051.
The study developed in this thesis concerns actinide oxides synthesis for nuclear fuel refabrication, and more specifically, the actinide (III) precipitation in molten salt LiCl-CaCl2 (30-70%mol) salt at 700°C using wet argon sparging. First, this conversion method is described for neodymium (III) and cerium (III) coconversion. The conversion rates are around 99.9%, and the obtained powders contain mixed oxychloride Ce1-xNdxOCl as main component, with a small amount of mixed oxide Ce1-xNdxO2-0.5x for the high cerium ratio. A second oxychloride CeIV(Nd0.7Ce0.3)IIIO3Cl is obtained in specific conditions and in very low quantity. The structure of this oxychloride is described in this study. The partially oxidative property of the conversion method induces the oxidation of a part of cerium (III) to oxidation state (IV). In the case of uranium (III) conversion by wet argon sparging, all the uranium is oxidized and give the oxide UO2 as single compound. The conversion rate for this element is over 99.9% in the molten chloride, but significant amount of uranium is lost by volatilization during the conversion. Finally, the U(III) and Pu(III) coconversion study shows the highest precipitation sensitivity of uranium (III) in comparison with plutonium (III), responsible of a successive conversion of the two elements, giving an oxide mixture of UO2 et PuO2 with quantitative conversion rate. Surprisingly, the conversion of Pu(III) in the same conditions led to a mixture of PuO2 and PuOCl, characteristic of a partial oxidation from Pu (III) to Pu (IV), in contrast with coconversion of U(III)-Pu(III)
DE, ROY GRIVEL MARIE ELISABETH. "Synthese par reduction electrochimique en milieu sel fondu et caracterisation d'oxydes doubles de vanadium a valence mixte." Clermont-Ferrand 2, 1991. http://www.theses.fr/1991CLF2E435.
Vigier, Jean-François. "Synthèse d’oxydes d’actinides en milieu chlorure fondu : études structurales et mécanismes réactionnels." Thesis, Lille 1, 2012. http://www.theses.fr/2012LIL10051/document.
The study developed in this thesis concerns actinide oxides synthesis for nuclear fuel refabrication, and more specifically, the actinide (III) precipitation in molten salt LiCl-CaCl2 (30-70%mol) salt at 700°C using wet argon sparging. First, this conversion method is described for neodymium (III) and cerium (III) coconversion. The conversion rates are around 99.9%, and the obtained powders contain mixed oxychloride Ce1-xNdxOCl as main component, with a small amount of mixed oxide Ce1-xNdxO2-0.5x for the high cerium ratio. A second oxychloride CeIV(Nd0.7Ce0.3)IIIO3Cl is obtained in specific conditions and in very low quantity. The structure of this oxychloride is described in this study. The partially oxidative property of the conversion method induces the oxidation of a part of cerium (III) to oxidation state (IV). In the case of uranium (III) conversion by wet argon sparging, all the uranium is oxidized and give the oxide UO2 as single compound. The conversion rate for this element is over 99.9% in the molten chloride, but significant amount of uranium is lost by volatilization during the conversion. Finally, the U(III) and Pu(III) coconversion study shows the highest precipitation sensitivity of uranium (III) in comparison with plutonium (III), responsible of a successive conversion of the two elements, giving an oxide mixture of UO2 et PuO2 with quantitative conversion rate. Surprisingly, the conversion of Pu(III) in the same conditions led to a mixture of PuO2 and PuOCl, characteristic of a partial oxidation from Pu (III) to Pu (IV), in contrast with coconversion of U(III)-Pu(III)
Boissière, Jean-Marie. "Synthèse par extrusion réactive de polycondensats de polyamides." Thesis, Vandoeuvre-les-Nancy, INPL, 2008. http://www.theses.fr/2008INPL062N.
The aim of this work is to study the feasibility of addition of nylon salt to polyamide (PA) by a reactive extrusion process. As example, the addition of 6T salt, which includes aromatic monomers, to PA 66 is performed in order to synthesize PA 66/6T. This latter replies to demand of high resistance temperature polymer. Consequently, the progress rate of the reaction and the rate of 6T motifs insertion have to be maximized.This work includes the synthesis and the analysis of 6T salt, PA 6T and PA 66/6T. 6T salt synthesis is performed since it is not commercialised. PA 6T is synthesized in order to identify aromatic hydrogen in PA 66/6T molecule. About this latter, it is necessary to adjust and to study the extrusion process. So, the influences of few process parameters are studied as, for example, pressure level on vent gas of the extruder.With the best process parameters, the progress rate is 93 mol% and the rate of 6T motifs insertion is 15,3 mol%. Yet, PA 66/6T presents a significant excess of acidic end group
Marote, Pedro. "Étude du rôle des sels précurseurs de métaux di et tétravalents et des ions alcalins, dans la synthèse d'oxydes en milieu nitrate et nitrite fondu." Lyon 1, 2001. http://www.theses.fr/2001LYO10161.
Boutin, Véronique. "Productibilité des centrales solaires à tour (filière sel fondu)." Nice, 1986. http://www.theses.fr/1986NICE4061.
Ganchegui, Benjamin. "Transformations palladocatalysées d'alcools et utilisation d'un sel fondu comme solvant." Reims, 2004. http://www.theses.fr/2004REIMS002.
The first part of this work deals with the Heck reaction of allylic alcohols in usual organic solvents. The various strategies employed to perform this reaction an enantioselective way resulted in relative defeat. Nevertheless, the use of this coupling as final step of a tandem reaction afforded the corresponding biarylketones with satisfying yields and selectivities. The second part of this work deals with the use of molten n-Bu(4)NBr as solvent for palladium catalyzed reactions. Efficient conditions were found for the Heck coupling of allylic alcohols, the dehydrogenation of benzylic alcohols and the isomerization of allylic alcohols. Moreover, in the three cases, the ionic catalytic layer was recycled without significant loss of activity. Finally, this work gives evidences for the formation of Pd nanoparticles in the course of these reactions carried out in the molten salt as solvent
VALADE, MYRIAM. "Etude de l'incineration des transuraniens en reacteur a sel fondu." Université Louis Pasteur (Strasbourg) (1971-2008), 2000. http://www.theses.fr/2000STR13196.
Oney, Gozde. "L'ordre des métaux de transition dans la phase spinelle LiNi0,5-xMn1,5+xO4 à haut potentiel : caractérisation multi-échelle jusqu'au nanomètre." Electronic Thesis or Diss., Bordeaux, 2023. http://www.theses.fr/2023BORD0457.
The performance of spinel LiNi0.5-xMn1.5+xO4 (LNMO) as positive electrode material in Li-ion batteries strongly depend on its synthesis conditions, Ni/Mn stoichiometry, and the degree of ordering of Ni and Mn. LNMO crystal structure can be described in Fd-3m or P4332 space groups, depending on the extent of this ordering. Understanding the impact of these structural properties on electrochemical performance is challenging due to the interdependent nature of each parameter and the limited spatial resolution of the common characterization techniques. In this study, we demonstrate the synthesis of impurity-free disordered (Fd-3m) platelets of LNMO presenting multiple surface orientations via molten salt synthesis. Thanks to the thin platelet morphology (thickness ~180 nm) achieved, we employed a 4D-STEM electron microscopy tool, newly growing in the battery field, to investigate the transition metal ordering on individual LNMO particles with nanometric spatial resolution for the first time. The unique ability to tune the primary particle morphology, spinel composition and control secondary phase generation enabled us to demonstrate that heterogeneity in the transition metal arrangement on the globally ordered (P4332) LNMO is beneficial for electrochemical performance. Combining electron microscopy analysis with average structural properties obtained through X-ray and neutron diffraction, and with information on the local environments obtained using Raman and 7Li NMR spectroscopies, we dissect the “synthesis-composition-properties” relation for LiNi0.5-xMn1.5+xO4 samples prepared through various annealing steps. This enables the obtention of high-performing (dis)ordered spinel LNMOs with diverse compositions, highlighting how the electrochemical properties can be tailored through structural design
Laudernet, Yann. "Approches classiques et quantiques de la solvatation et de la spéciation des ions en solution et en sels fondus chlorés et fluorés." Paris 6, 2002. http://www.theses.fr/2002PA066491.
Docters, Tamara. "Influence des conditions de synthèse en milieu sels fondus et des traitements postérieurs sur l'efficacité photocatalytique de TiO2." Lyon 1, 2005. http://www.theses.fr/2005LYO10040.
Lucas, Marie. "Microscopie electrochimique en milieu sel fondu : experience, modelisation et application à l'étude de la corrosion." Paris 6, 2013. http://www.theses.fr/2013PA066439.
This work deals with the electrochemical microscopy at high temperature and its modeling for understanding of corrosion in molten salts. The SECM was adapted to the eutectic LiC1-KC1 at 723 K. Particular attention was then given to the designs of the microelectrode and electrochemical cell and the choice of redox mediator. The SECM was then validated by the recording an approach curve in the eutectic LiC1-KC1 with the use of indium as a mediator. Then, the metal cations of interest to study the corrosion of nickel-chromium alloys were characterized by electrochemistry. The device was then calibrated for the study of corrosion in the molten salt. The SECM probe was placed close to the Haynes 230 alloy in the eutectic LiC1-KC1 at 723 K, the composition of the corrosion products were electrochemically determined and corrosion kinetics were calculated using the calibration. In parallel , several programs of two and three dimensions numerical simulation were developed to simulate the electrochemical experiments. A validation of these models was then carried out by comparison with the theory and / or experiments. Finally , SECM mapping and detection at a microelectrode of ions released by corrosion of a substrate were modeled, reproducing the experimental results qualitatively and / or quantitatively
Boutin, Véronique. "Productibilité des centrales solaires à tour, filière sel fondu analyse détaillée des postes de perte." Grenoble 2 : ANRT, 1986. http://catalogue.bnf.fr/ark:/12148/cb375963788.
Ayoub, Ali Samir. "Synthèse, structure et propriétés des amidons modifiés en milieu fondu peu hydraté." Reims, 2004. http://www.theses.fr/2004REIMP202.
@This work presents the settling of starch syntheses modified in medium molten little hydrated, transposable on an industrial scale, and of the techniques of characterization adapted to these polysaccharides. The synthesis was developed starting from native starch of corn and without solvent, the reaction being carried out in the presence of soda and of the reagents. The application of thermomechanical energy showed a significant acceleration of the kinetics of the reaction. The characterization of the modified starches was carried out by several analytical techniques (NMR, MEB, intrinsic viscosity. . . ). These technique made it possible to study the influence of the physicochemical modification in molten medium. The enzymatic degradation of the modified starches showed the influence of the physicochemical modification on the profile of degradation
Crinière, Guillaume. "Nouvelles phases pyrochlores lacunaires obtenues par désintercalation en milieu réducteur et/ou par réaction d'échange en milieu sel fondu." Phd thesis, Université Sciences et Technologies - Bordeaux I, 2002. http://tel.archives-ouvertes.fr/tel-00008465.
Kessler, Olivier. "Alliages réfractaires résistants à la corrosion par le verre fondu : synthèse et caractérisation." Nancy 1, 1997. http://www.theses.fr/1997NAN10311.
Synthesis of refractory base alloys by sintering or inductive melting : optimisation of the methods and characterization of these alloys. Evaluation of some physical and chemical properties at 1300°C : - isothermal oxidation resistance in air, (thermogravimetry) - dynamic corrosion resistance in molten glass, (turning finger test) - creeping resistance. (creeping in flexion with three or four contact points)
Detoisien, Thibaud. "Cristallisation d'un sel pharmaceutique : développement de méthodologies d'étude." Aix-Marseille 3, 2010. https://hal.archives-ouvertes.fr/tel-02003175.
The salt formation of an active pharmaceutical ingredient (API) changes some physical and chemical properties of an API, such as its stability and its bioavailability. Pharmaceutical salts represent two thirds of the APIs in the pharmaceutical market world. Salt formation (acid-base reaction) can be coupled with its precipitation and pH monitoring helps understanding the chemical equilibriums. The bibliography part of this document focuses on Cs = f (pH) theoretical curves writing and the reasons leading to a choice of a particular salt of an API. The chosen API for this work is an hydrochlorate that crystallizes as needles. The work at the CINaM lab consisted first in developing a polymorphs screening method with the fewest materials in a short time-lapse. 12 phases have been discovered, 2 as anhydrous phases, 5 hydrates and 5 solvates. A monocrystal of the API base has been prepared to analyze its crystalline structure and to compare it to a salt structure solved by some molecular modelisation work. Solubility measurements in ethanol/water mixes helped us prepare our work at the LAGEP lab for crystallization studies in an homothetic reactor under stirring. In situ monitoring with FBRM and video probes helped us understand the effect of a particular crystallization process on crystal properties. The best process, crystallization with seeding, has been studied in details. Unfortunately, the salt/solvent combo choice has been fixed before the thesis, which hasn’t allowed us to develop a process to crystallize another phase with a different habit
Crassous, Isabelle. "Contribution à la mise au point d'un nouvel électrolyseur pour la production de fluor en milieu sel fondu KF-2HF." Paris 6, 2009. http://www.theses.fr/2009PA066704.
Huguet, Anne. "Un nouveau concept de séparation actinides-lanthanides en milieu sel fondu : mise en oeuvre d'une cathode liquide à surface renouvelée." Phd thesis, Grenoble 1, 2009. http://www.theses.fr/2009GRE10302.
This study is part of a research program concerning the assessment of pyrochemical methods for the nuclear waste processing. The An-Ln partitioning could be achieved by an electrolytic selective extraction in molten salt media. It has been decided to focus on liquid reactive cathode which better suits to a group actinides co-recycling. The aim of the study is to propose, define and initiate the development of an electrolytic pyroprocess dedicated to the quantitative and selective recovery of the actinides. Quantitativity is related to technology, whereas selectivity is governed by chemistry. The first step consisted in selecting the adequate operating conditions, which enables a sufficient An-Ln separation. The first step consisted, by means of thermodynamic calculi and electrochemical investigations, in selecting a promising combination between molten electrolyte and cathodic material, regarding the process constraints. To improve the recovery yield, it is necessary to develop a disruptive technology : here comes the concept of a dynamic electrodeposition carried out onto liquid metallic drops. The next step consisted in designing and manufacturing a lab-scale device which enables dropping flow studies. Since interfacial phenomena are of primary meaning in such a concept, it has been decided to focus on high temperature liquid-liquid interfacial measurements
Huguet, Anne. "Un nouveau concept de séparation actinides-lanthanides en milieu sel fondu : mise en oeuvre d'une cathode liquide à surface renouvelée." Phd thesis, Université Joseph Fourier (Grenoble), 2009. http://tel.archives-ouvertes.fr/tel-00539606.
Igoa, Saldaña Fernando. "Templated syntheses towards new boron-based nanomaterials." Electronic Thesis or Diss., Sorbonne université, 2022. https://accesdistant.sorbonne-universite.fr/login?url=https://theses-intra.sorbonne-universite.fr/2022SORUS459.pdf.
Boron-containing compounds exhibit several physical properties exploitable for current industrial needs, i.e. catalytic activity, magnetism, supercapacitance, high Li+ storage capacity and excellent mechanical properties. Most of these properties can be tailored and ideally optimized by shaping the material into nanostructured morphologies. However, the strong covalent nature of boron bonding hurdles the synthesis of nanostructures, as high input energy is needed to form such bonds. This translates in elevated synthesis temperatures, which ultimately also trigger grain growth. Molten-salts synthesis has gained considerable attention as a synthetic tool to yield nanostructures. Molten-salts permit to perform chemical reactions under a liquid media in a range of temperatures sufficiently large to trigger borides crystallization, but soft enough to limit their growth. Despite its success, the control over the product’s morphology remains a significant challenge. In some cases, this can be overcome by isomorphic methods, i.e., using nanoparticles as precursors, which undergo internal restructuration, so that they could also act as nanotemplates. In this thesis work, the use of nanotemplates coupled to molten salts synthesis of nanomaterials has been explored for two challenging boron-based systems. Firstly, boron carbide nanostructures were synthesized from sodium carbaboride templates, themselves synthesized in molten salts. The interest behind producing boron carbide nanostructures has been largely recognized in the literature, as a way to ameliorate its hardness and durable use as a structural material. The template synthesis is achieved thanks to the reaction between a polymeric carbon source (polyethylene) and NaBH4 in molten NaI, which yield ~ 5 nm nanoparticles. These nanoparticles can be successfully transformed to boron carbide while maintaining the nanoscale morphology by thermal decomposition. Furthermore, the processing of boron carbide into dense monoliths was also studied by means of spark-plasma sintering. Once proper densification and consolidation were achieved, the mechanical properties of the boron carbide nanostructures were investigated. We then highlighted a significantly higher hardness and amorphization resistance than the bulk counterpart. In parallel, a layered metal boride system has also been investigated with analogous procedures. The system in question is Fe2AlB2, consisting of Fe2B2 layers intercalated by Al layers. This phase has raised enormous interest as a possible parent phase towards bidimensional Fe2B2. The synthesis of Fe2AlB2 presents several difficulties though. We have herein exploited the templating approach in molten salts from a bulk FeB template, which we demonstrate that upon Al insertion in molten LiCl/KCl yields Fe2AlB2. The Fe2AlB2 phase delamination towards 2D-Fe2B2 was investigated by selective oxidation of the Al atoms. Although delamination did not occur, we evidenced an abnormal thermal behaviour in Fe2AlB2. When thermally treated, Fe2AlB2 expulses Fe and B atoms out of the structure, generating vacancies. This mechanism was demonstrated by in situ X-ray diffraction and post mortem analyses
Besançon, Manon. "Synthèse in situ de nanocomposites par chimie sol-gel non-hydrolytique en voie fondu." Electronic Thesis or Diss., Lyon, 2020. https://n2t.net/ark:/47881/m6pn95cw.
Polymer nanocomposites have drawn considerable attention due to the improvement of structural and functional properties of polymer based systems. The common way to elaborate nanocomposites is the dispersion of fillers into the polymer. However, the agglomeration of nanofillers in the polymer and the increasing concerns about the manipulation of nanoobjects are the main issues of this technique. To overcome these problems, a “bottom-up” approach has been developed in recent years combining reactive extrusion and hydrolytic sol-gel chemistry. This approach has some limitations for non-polar polymers. Indeed, water is required and the surface of such inorganic phases presents hydroxyl groups involving a weak interaction with the polymer matrix. Our approach is to use non-hydrolytic sol-gel chemistry to generate nanofillers in the molten polymer. The specificity of NHSG is the use of an oxygen donor instead of water and the ability to control the shape and the size of nanofillers. Syntheses of titanium dioxide and layered titanium phosphonates were carried out in molten polymer. Different precursors were investigated in order to improve the compatibility between matrix and fillers and obtain homogeneous dispersion of small size fillers. The influence of the polymer nature on the obtained fillers morphology has also been studied
Mathieu, Ludovic. "Cycle thorium et réacteurs à sel fondu : exploration du champ des paramètres et des contraintes définissant le "Thorium Molten Salt Reactor"." Phd thesis, Grenoble INPG, 2005. http://tel.archives-ouvertes.fr/tel-00010791.
Rodrigues, Davide. "Solvatation du thorium par les fluorures en milieu sel fondu à haute température : application au procédé d'extraction réductrice pour le concept MSFR." Thesis, Université Paris-Saclay (ComUE), 2015. http://www.theses.fr/2015SACLS150/document.
The molten salt fast reactor (MSFR) is one of the six nuclear reactor concepts retained during the Forum GEN IV in 2001. The particularity of this concept is to use a liquid fuel consisting of a molten salt, LiF-ThF₄-UF₄ /UF ₃ (77-19-4 mol%) and to have an integrated spent fuel treatment process. This treatment consists of successive chemical separation steps based on redox and acid-base properties of the elements produced in the reactor by nuclear reactions: soluble and gaseous fission products, metals elements and soluble minor actinides. One of the major steps of the treatment method is a reducing extraction which consists to contact the molten salt and a liquid metal, bismuth, containing the reducing element, lithium. This step allows separating the minor actinides and lanthanides. Minor actinides are reintroduced in the nuclear reactor to be burned while the lanthanides are confined in deep storage.The work in this thesis had two objectives: (i) assess the feasibility of reducing extraction of actinides and lanthanides, a step that had previously only been validated on the basis of thermodynamic calculations and (ii) study the chemistry of molten fluoride salts (and especially the fuel salt) by developing a methodology for the determination of fundamental data such as the activity coefficients in fluorides media, coefficients activities which quantify the solvation properties.To experimentally realize a reducing extraction, the first step is to prepare a metal layer of liquid Bi-Li with predefined composition. An electrolysis technique in molten salt LiCl-LiF at 550°C was chosen to achieve these metal solutions. We have shown that only this molten medium could be used for the manufacture of such metal alloys. Extraction tests were then carried out by contact between LiF-ThF₄ (with UF₄ and NdF ₃ are introduced to simulate respectively the actinides and lanthanides) and Bi-Li at 650°C. The main results show that the extraction of neodymium and uranium was obtained with yields of around 3% and 15% respectively in the best conditions. These values are low compared to previous thermodynamic calculations. Low efficiency of the extraction is due to a simultaneous extraction of thorium in the liquid metal phase which forms intermetallic compounds at the metal/salt interphase and blocks the transfer.Methods have been developed to achieve fundamental data that are lacking in molten fluoride medium, in particularly the solvation properties. Speciation of some metallic cations by fluoride ions with high temperature was particularly studied and calculation of complexation constants by simulated experimental results was done. Carried out for two lanthanides, neodymium and lanthanum, two actinides, thorium and uranium, and also for a transition metal, nickel, this study achieves to calculate the activity coefficients of these elements in different fluoride molten salt. The study of the speciation of thorium was an important step to understand the chemistry of the fuel salt LiF-ThF₄. We were able to calculate the activity coefficient of the fluoride ion in this environment at 650°C.Finally, all of this work allows giving a first estimate of the reactivity of each element of the periodic table (present in the nuclear reactor after operation) at each stage of the treatment of the spent fuel salt
Chan, Chang Tsou Hsi Camille. "Elaboration de borures et phosphures métalliques : synthèse de nanomatériaux en sels fondus et réactivité de surface." Thesis, Paris 6, 2017. http://www.theses.fr/2017PA066213/document.
This PhD work deals with a novel synthesis of metal boride and metal phosphide nanomaterials. Nanostructures of these solids are subject to an increasing interest due to their exciting properties for various applications fields such as superconductivity, high temperature thermoelectricity, energy conversion and storage. In this work, the catalytic and electrocatalytic properties of these nanomaterials are explored. First of all, borides of various transition metals, such as nickel, palladium or a nickel-cobalt composite are studied. To do so, a new liquid-phase synthesis was developed, based on the reactivity of already formed metal nanoparticles with a boron precursor in inorganic molten salts. This new synthesis allowed a precise control over the nanoparticle morphology, size, composition and crystalline structure. By accessing such nanoscale objects, we were able to investigate their properties and performances, especially in the fields of catalysis with the hydrodeoxygenation reaction and electrocatalysis for the hydrogen evolution reaction and oxygen evolution reaction. Finally, the reactivity of red phosphorus in molten salts was addressed, thus paving the way to the extension of this synthetic pathway to metal phosphides
Lecarpentier, David. "Contribution aux travaux sur la transmutation des déchets nucléaires, voie des réacteurs à sel fondu : le concept Amster, aspect physique et sureté." Paris, CNAM, 2001. http://www.theses.fr/2001CNAM0386.
Delacroix, Simon. "Synthèse de nanomatériaux riches en bore." Electronic Thesis or Diss., Sorbonne université, 2019. https://accesdistant.sorbonne-universite.fr/login?url=https://theses-intra.sorbonne-universite.fr/2019SORUS483.pdf.
During this PhD we have developed a new synthetic pathway towards nanoparticles containing light elements especially boron. The nanostructuration of such materials could lead to increase their properties like hardness. Unfortunately, the synthesis of such nanomaterials is very complicated. Indeed, a complex network of covalent bond existing in these materials should be organized during the synthesis and the crystallization at high temperature which lead to the growth of the particles. To answer this synthetic challenge, we have coupled two classically separated worlds: high temperature colloidal chemistry synthesis. and high pressure physics. Nanoparticles are synthesized in inorganic molten salts (alkali halides) to obtain various materials such lithium boride, alkaline borocarbides, amorphous boron and boron carbides of different ratio. The study of structural transitions of this compounds is realized at high temperature under high pressure in a Paris Edinburgh or a multi anvil press. Thanks to the nanostructuration of the precursors, surface energy plays an important role during the crystallization and could lead to the formation of new metastable phases. The pressure limit the growth of the initial particles and allow us to visit a large space in the phase diagrams of this different compounds studied in this PhD
Gonnot, Vanessa. "Synthèse de molécules d'intérêts thérapeutique: Rhéine et Méquitazine : Mise au point de procédés de synthèse." Strasbourg 1, 2007. http://www.theses.fr/2007STR13241.
This Ph-D work in collaboration with Laboratoires Pierre Fabre has lead to the developpment of new synthetic routes to biologically active coumpounds. In chapter 1, we have synthetised Mequitazine by a new route. Key step is a palladium-catalysed allylic substitution on a new allylic substrate. Racemic Mequitazine is obtained by hydrogenation in the last step, but this route could lead to biologically active Mequitazine enantiomer by the mean of an asymmetric hydrogenation catalyst. Two new ways for the synthesis of Rhein has been developped in chapter 2. They are both based on ortho-metallation reaction. The first route has been optimised so that it can be used industrially, while the second one, by changing the electrophile, leads to Rhein in only three steps. Last step’s Friedel Crafts’acylation selectivity has been improved by detailed study of Hayashi rearrangement in molten salt. In a third chapter, a new method for converting -fluorocyanhydrines into aldehydes has been studied
Paci, Benjamin. "Synthèse et caractérisation de polyimides semi-aromatiques obtenus par polymérisation à l'état solide de sel." Thesis, Lyon, INSA, 2014. http://www.theses.fr/2014ISAL0137.
Polyimides are known as high performance polymers, they are used in harsh environments (high temperatures, high pressure, …). They also have low processibility. The most used industrial synthesis process is using poly(amic acid) as reaction intermediate. This process requires high prices solvents that are harmful for human being and environment such as n-methyl-2-pyrrolidone and cresol. Semi-aromatic polyimides have lower characteristic temperatures and can thus be processed easily. A new way of synthesis based on salt polymerisation can be used to synthesize polyimides (aromatic or not), this process only needs simple solvents such as water or ethanol. Numerous researches have been made on this subject in the past 50 years. To our knowledge, this technique is not used at industrial scale. The goal of this work is to synthetize semi-aromatic polyimides using solid-state salt polymerisation. A preliminary examination on low weight molecules allowed us to highlight critical parameters on every step of reactions and thermal behaviour. Both salification and polymerization protocols are been made with the view to synthetize 3 soluble polyimides. This solubility allowed us to characterize our polymers and to enhance polymerization control. Those characterizations provided us answers on salification and polymerization mechanisms. Two molar mass control techniques have then been compared in terms of industrialization and efficiency. At the end, polymers have been synthetized, processed and then characterized in physic-chemical and mechanical ways
Chan, Chang Tsou Hsi Camille. "Elaboration de borures et phosphures métalliques : synthèse de nanomatériaux en sels fondus et réactivité de surface." Electronic Thesis or Diss., Paris 6, 2017. https://accesdistant.sorbonne-universite.fr/login?url=https://theses-intra.sorbonne-universite.fr/2017PA066213.pdf.
This PhD work deals with a novel synthesis of metal boride and metal phosphide nanomaterials. Nanostructures of these solids are subject to an increasing interest due to their exciting properties for various applications fields such as superconductivity, high temperature thermoelectricity, energy conversion and storage. In this work, the catalytic and electrocatalytic properties of these nanomaterials are explored. First of all, borides of various transition metals, such as nickel, palladium or a nickel-cobalt composite are studied. To do so, a new liquid-phase synthesis was developed, based on the reactivity of already formed metal nanoparticles with a boron precursor in inorganic molten salts. This new synthesis allowed a precise control over the nanoparticle morphology, size, composition and crystalline structure. By accessing such nanoscale objects, we were able to investigate their properties and performances, especially in the fields of catalysis with the hydrodeoxygenation reaction and electrocatalysis for the hydrogen evolution reaction and oxygen evolution reaction. Finally, the reactivity of red phosphorus in molten salts was addressed, thus paving the way to the extension of this synthetic pathway to metal phosphides
Sanglar, Corinne. "Prépolymères à terminaisons propargylique et chromène. : Synthèse, études physicochimiques, mécanismes et cinétique de polymérisation à l'état fondu." Pau, 1995. http://www.theses.fr/1995PAUU3025.
Ouahdi, Noura. "Synthèse de l’aluminate de cobalt par voie sels fondus, caractérisation et application à la coloration des carreaux céramiques industriels." Toulouse 3, 2005. http://www.theses.fr/2005TOU30273.
The objective is the synthesis, by molten salts route, of a major industrial blue pigment, the cobalt aluminate. The powders obtained have been characterized by ICP, XRD, DTA/TGA, FTIR, SEM and TEM, UV-Visible spectroscopy and colourimetric analysis by the L*a*b* method. The reaction of cobalt and aluminium chlorides in molten medium constituted of alkali-metal nitrates, chlorides or sulfates always lead to mixtures of phases (Co3O4, CoAl2O4 and g Al2O3) which composition is depending on the nature of the molten bath. These mixture are very reactive and are transformed in CoAl2O4 by heating at 1000°C without any plateau. The double decomposition reactions between the mixed alkali-metal oxyde g LiAlO2 and the double chloride KCoCl3, at 500°C for 24 hours, lead directly to crystallized cobalt aluminate. The powders obtained have been characterized, then tested for the colouring of ceramic tiles comparatively to an industrial pigment. The tests, performed in the moroccan society Union Cerame, confirm that the pigment synthesized in molten salt medium is a good candidate for the use in the colouring of industrial ceramic tiles
Laborie-Crémont, Hélène. "Synthèse de nouveaux inhibiteurs de kinases d'origine marine à visée thérapeutique." La Rochelle, 2009. http://www.theses.fr/2009LAROS278.
In an effort to develop new marine inhibitors of kinases as anticancer and anti-Alzheimer’s disease agents, we synthesized original indigoids substituted in position 1, 5, 5’, 6, structurally closed to marine indirubins. Because of their poor water solubility and low bioavailability, monoxime analogs were also prepared. The effect on cyclin dependant kinases, glycogen synthase kinase 3, casein kinase 1 and on the survival of human neuroblastoma SH-SY5Y cells were estimated. On the other hand, we synthesized new 1,2,3-dithiazoles via Appel’s Salt chemistry, which are closed to marine hamacanthin. These compounds were screened for their antibacterial, antifungal and antitumor activity
Durán-Klie, Gabriela. "Étude du comportement de l’uranium et de l’iode dans le mélange de fluorures fondus LiF-ThF₄ à 650 °C." Thesis, Université Paris-Saclay (ComUE), 2017. http://www.theses.fr/2017SACLS268/document.
The Molten Salt Fast Reactor (MSFR) is an innovative concept of GEN IV developed by the CNRS since 2004. It is currently studied in the framework of the European project SAMOFAR of H2020. The MSFR operates with a liquid nuclear fuel consisting of a mixture of fluoride salts LiF-ThF₄- (UF₄ / UF₃) (77.5-20-2.5) mol% melted at high temperature (700-900° C). This reactor is particularly advantageous for the thorium fuel cycle (²³²Th-²³³U). This concept proposes an integrated reprocessing of the nuclear fuel based on pyrochemical methods in order to extract the fissile material and to separate the actinides from the fission products.A scheme for the treatment of the fuel salt, proposed in a previous European project (EVOL, FP7), is based on the redox and acido-basic properties of the elements produced by the fission and capture reactions occurring in the reactor core. The baseline for this scheme was initially thermodynamic. Experimental validation is currently under way to study the chemical and electrochemical behavior of the molten salt and the elements solubilized therein. Previous studies on molten salt reactors can only be partially used for this concept because the composition of the MSFR salt defined by the European EVOL project is different from the composition of the salts proposed up to now for this type of reactor. However, the diffusion and activity coefficients depend on the physicochemical properties of the molten salt (in particular solvation) and in previous studies we have shown that the solvation properties of molten salts are strongly dependent on their nature and their composition.The objectives of this thesis are the electrochemical characterization of the molten mixture LiF-ThF₄ and the study of the electrochemical behavior of uranium and iodine.The electrochemical study of the behavior of uranium shows the stability of two soluble species (UF₄ and UF₃) of this element in the molten medium and the possibility of its reduction to the metallic state. This point is important because the co-existence of these two compounds will make possible to control the potential of the fuel salt in the core of the reactor in order to limit the corrosion reactions with the structural materials. The activity coefficients of U (IV) and U (III) were determined. The values obtained show that the solvation of uranium to the degree of oxidation (IV) by fluoride ions is much greater than that of uranium to degree (III), which is in agreement with subsequent observations in other fluoride salts.Our choice for the study of fission products in the fuel salt has focused on iodine. In the core of the reactor, the stable form of the iodine is the soluble halide form I- and in the general scheme of treatment of the fuel salt, it is planned to extract iodine by a fluorination step in order to produce the gaseous compound I₂. The electrochemical study shows the contribution of a chemical reaction to the electrochemical oxidation of iodide ions in gaseous iodine. This redox chemical reaction corresponds to the oxidation of the iodide ions by oxygen. This reaction is explained for the existence of a soluble thorium oxifluoride ThOF₂. Extraction efficiencies of I₂ (g) greater than 95% were obtained by electrolysis at controlled potential. These electrolysis, which simulate fluorination process, make it possible to validate the method for the extraction of the iodine in the reprocessing scheme.This research has led to a better understanding of salt stability and of the chemical and electrochemical behavior of several compounds (U and I) in the molten salt
Perrier, Damien. "Mise en oeuvre et caractérisation d'un nouveau procédé électromagnétique destiné à favoriser les transferts de masse aux interfaces entre un métal liquide et un sel fondu." Grenoble INPG, 2002. http://www.theses.fr/2002INPG0124.
A new electromagnetic process is set up in order to improve the mass transfers between a molten metal and a slag. The principle of the process consists to melt and stir the metal in an cold-crucible induction furnace supplied with a two-frequency alternating current. This inductive current contains a basic frequency to heat and ensure an electromagnetic stirring of the bulk metal as well as a low modulation frequency in order to destabilize the interface metal - slag. Such an inductive current is obtained by modulating the input instruction of a standard induction generator using a sinusoidal signal delivered by a function generator. A study of the hydrodynamic behaviour of the free surface of gallium in such a two-frequency induction system showed that it is possible to excite axisymetric oscillation modes when the modulation frequency of the inductive current corresponds to the eigenfrequency of the oscillation modes. The maximum amplitudes and the frequency of the deformations of the free surface were measured according to the modulation parameters imposed on the induction generator. The experimental features of the free surface oscillations agree qualitatively with those predicted by the analytical model. A system of detection of resonance, without contact with the free surface, was set up in order to detect the deformations of the free surface generated by the excitation of the oscillation modes. The aptitude of the process to improve the kinetics of transfer of zirconium from a fluorinated salt to a molten metal containing aluminium as reducing agent was studied. Experiments of transfer were carried out without and with modulation of the inductive current. They showed that, for a fixed value of the current, the transfer can be accelerated thanks to the interfacial agitation generated by the modulation of the inductive current
Benamira, Aziza. "Mise au point d'une synthèse, en milieu oxonitrates alcalins fondus, de poudres de hafnone pure ou stabilisée : caractérisation, frittage et essais mécaniques." Lyon 1, 1997. http://www.theses.fr/1997LYO10304.
Capitolis, Jérôme. "Synthèse de nanoparticules d'oxydes de titane ou de vanadium à basse valence." Electronic Thesis or Diss., Sorbonne université, 2018. https://accesdistant.sorbonne-universite.fr/login?url=https://theses-intra.sorbonne-universite.fr/2018SORUS499.pdf.
This PhD work deals with the development of new synthesis pathways for low valence titanium or vanadium oxide nanoparticles. These oxides are attracting an increasing interest for applications such as thermoelectricity, data or energy storage, especially at the nanoscale where performances can be enhanced. However the synthesis of these solids at nanoscale is a challenge. In this work, the synthesis of nanoparticles of several low or mixed valence titanium oxides is studied. The approach that are explored are based on the reduction of titanium dioxide nanoparticles by metallic hydrides in molten salts. It enables control over phase, size and morphology of the nanoparticles. The synthesis of V2O3 nanoparticles from molecular precursors in molten salts has also been developed, in order to control the structure, size and morphology of the nanoparticles. This pathway enables the synthesis of a non-identified vanadium containing oxide and lays the foundation for the synthesis of vanadium Magnéli phases at the nanoscale. Finally the surface reactivity of nanoparticles of Ti4O7 and Ti6O11 Magnéli phases were explored by Near ambient pressure-X ray photoelectron spectroscopy
Da, Cunha Louis. "Synthèse, mécanisme et cinétique de polymérisation à l'état fondu de prépolymère à réactivité élevée et sélective de type bismaleimide." Pau, 1996. http://www.theses.fr/1996PAUU3036.
Theil, Perrine. "Synthèse de nouveaux ignifugeants par génération in situ de charge inorganique à base de phosphore en matrice polymère fondu." Lyon 1, 2008. http://n2t.net/ark:/47881/m60g3h8g.
This work presents an unusual approach to prepare a new flame retarded PA6 containing phosphorylated silica formed in situ during extrusion process. This nanocomposite is based on sol-gel method without solvent through reactive processing. A first fundamental point was to evaluate the kinetics and the structure of the inorganic species by carrying out these sol-gel reactions in a model medium of PA6 which is N-methyl acetamide. Thus, it was evidenced that the amide medium is advantageous to perform these reactions. Then, the phosphorus alcoxysilane derivative, the diethylphosphato-ethyltriethoxysilane (SiP) is incorporated in molten PA6. The physical and chemical characterizations of the materials elaborated by reactive extrusion showed the formation of phosphorylated particles in the polymer matrix. Finally the fire retardant properties were evaluated and it reveals that the heat release rate was diminished by more than 50% with only 2w% of phosphorus compared to the pure PA6. This was explained by the formation of a carbonaceous char preventing the heat and the combustion products to diffuse
Tadlaoui, Khalid. "Synthèse d'oligomères du méthacrylate de méthyle par télomérisation radicalaire et étude de leurs comportements viscoélastique [sic, au singulier] à l'état fondu." Montpellier 2, 1989. http://www.theses.fr/1989MON20178.
Leymarie, Ludovic. "Étude de la synthèse à l’état fondu de copolymères contenant des blocs de polydiméthylsiloxane à l’aide de la réaction époxy-amine." Thesis, Lyon 1, 2012. http://www.theses.fr/2012LYO10055.
Nowadays hard-soft block copolymers consist of a very attractive material class because of their properties resulting of the combination of two different homopolymers. In the case of block copolymers with on a high polydiméthylsiloxane (PDMS) content, an innovative 2-step synthesis method, compatibilization and extension, has been developed. Using an environmental friendly route such as a reactive extrusion process, this approach opens a new synthesis pathway towards the development of thermoplastic elastomers. The goal of this thesis is to develop mass block copolymers based on PDMS using the epoxy-amine reaction, followed by an extension reaction to reach a material with a high percent of silicone. Firstly, a study of the epoxy-amine reaction on model molecules was carried out between a low molecular weight PDMS and an alkylamine. Independently of the temperature and the molar ratio, the reaction allowed to obtain graft copolymers with an (A2B2)n type structures. Secondly, this strategy has then been applied in polymer systems such as polyethylene and polyamide. At this scale, the reaction occurred and lead to products with (A2B2)n type structures. Thirdly, all synthesized copolymers were studied during the extension reaction, based on the insertion of cyclic siloxanes using a catalysis system. Depending of the temperature and the catalyst quantity, this reaction was investigated on model molecules and polymer systems
Georges, Peggy. "Volatilisation et condensation du potassium dans les silicates fondus : approche expérimentale et thermodynamique : applications cosmochimique et sidérurgique." Nancy 1, 2000. https://hal.univ-lorraine.fr/tel-01746432.
Mohamedi, Mohamed. "Étude électrochimique de l'indium en milieu LiCl-KCl fondu à 450°C." Grenoble INPG, 1995. http://www.theses.fr/1995INPG0020.
Ladhari, Neji. "Contribution à l'étude de la synthèse du sel de sodium de l'acide dinaphtylméthnedisulfonique et étude de différents paramètres influençant son effet dispersant." Mulhouse, 1997. http://www.theses.fr/1997MULH0471.
Graindorge, Hervé. "Etude du procédé continu de synthèse du sel sulfoacétique de trimethyl-2, 4, 6 pyrylium et de la 2, 4, 6-collidine." Aix-Marseille 3, 1987. http://www.theses.fr/1987AIX30007.
Letribot, Boris. "Synthèse et évaluation biologique de nouveaux composés hétérocycliques potentiellement inhibiteurs de protéine-kinases." Thesis, La Rochelle, 2015. http://www.theses.fr/2015LAROS002/document.
Deregulation of protein kinases leads to numerous pathologies such as cancers and neurodegenerative diseases. In order to identify new scaffolds able to inhibit this proteins we synthesized new 3-alkenyl-oxindoles. By the mean of Appel’s salt chemistry, we develop a new synthetic route to this skeleton. Our approach allows variation of the substituent of the exocyclic akene which can be functionalized by heterocycles, amino-nitriles or thio-nitrile which are obtained after selective ring opening of (1,2,3)-dithiazoles. In another part, given powerful indirubin kinase inhibitory potency, we synthesized new analogs indiribunoids and isoindigoids. In both cases (3-akenyl-oxindoles from Appel’s salt chemistry and indigoids), the aromatic ring were substituted by various electron withdrawing group and nitrogen were incorporated to determinate structure activity relationship. All this 80 original 3-alkenyl-oxindoles were evaluated for their ability to inhibit kinase activity and cell proliferation
Crochet, Guillaume. "Synthesis of stimuli responsive nanoparticles for electrocatalysis." Electronic Thesis or Diss., Sorbonne université, 2021. https://accesdistant.sorbonne-universite.fr/login?url=https://theses-intra.sorbonne-universite.fr/2021SORUS313.pdf.
Perovskite oxides are studied since decades for their magnetic properties and more recently for their electrocatalytic properties in the context of energy conversion, within fuel cells and water electrolyzers, for instance. In this work, we have aimed at developing new perovskite-based electrocatalysts operating in aqueous media, by targeting nanoscaled perovskites able to interact with their environment and then to exhibit stimuli-dependent electrocatalytic properties. This work was then at crossroad between the development of synthesis strategies, the design of nanomaterials, the study of their electrochemical and magnetic properties and of their interplay. We first describe a synthesis strategy suitable to reach quaternary perovskites by using molten salt media, innovative microwave heating and precise tuning of the oxo-basicity of the melt. We then address the relationship between magnetism and electrocatalysis on the case study of La0.7Sr0.3MnO3 nanocrystals derived from molten salts, through the development of an original set-up enabling triggering changes in the oxygen reduction reaction electrocatalysis by application of a magnetic field. We especially stress out the important of the composition of the electrolyte for magnetic enhancement of electrocatalytic activity. Finally, we address another way to trigger “externally” the properties of nanoscaled perovskite oxides, by developing a synthesis of doped perovskite nanocrystals and then by triggering under reducing conditions the exsolution of the metal cation dopants as metal nanoparticles at the surface of perovskite nanocrystal hosts, for the first time
Rolland, Dalon Edouard de. "Borides and borophosphides at the nanoscale : liquid-phase synthesis and electrocatalytic water splitting properties." Electronic Thesis or Diss., Sorbonne université, 2023. http://www.theses.fr/2023SORUS261.
Transition metal borides and phosphides present interesting properties in electrocatalysis for the production of dihydrogen. In these materials, the p-block element modifies the electron density of the metal atoms, which not only makes these materials resistant to oxidation and corrosion, but also modifies the catalytic properties. The development of catalysts requires the design of objects with a high surface/volume ratio, i.e. at the nanoscale. It is therefore essential to develop synthesis routes adapted to obtaining these materials and to the search for new compounds. In particular, combining boron with phosphorus and/or one or more transition metals in the same compound could lead to profound changes, notably in the electron density of the metal sites and the geometry of surface sites, due to the formation of specific crystalline structures constrained by the presence of covalent bonds. In view of the properties of the binary phases, all the modifications in terms of morphology, geometry and composition make it possible to control the reactivity and (electro)catalytic properties. This thesis work focused on the development of transition metal borides and borophosphides, with the objectives of morphological control on the nanometric scale, the development of new compounds, including metastable ones, and the characterisation of their electrocatalytic properties. The synthesis approaches chosen are based on two pillars. Firstly, molten salts, which enable synthesis to be carried out in the liquid state and at temperatures intermediate between those of solid-state chemistry and those of colloidal routes. Thus, the reaction media are homogeneous, enabling greater reactivity between soluble or dispersed precursors, and limiting the coalescence of particles. The other pillar is the use of metallic nanoparticles as nanoreactors in which boron and/or phosphorus are incorporated, so as to maintain the morphology of the particles. In this way, we obtain pure-phase nanomaterials in the case of nickel and iron borides, with a degree of control over composition and morphology that has never been achieved before. This control could only be achieved by understanding the formation mechanisms of the corresponding compounds and nano-objects. This understanding was achieved by developing in situ monitoring of the syntheses using X-ray diffraction under synchrotron radiation. We were thus able to identify reaction intermediates in the form of amorphous nanoparticles, the nature of which was elucidated using total X-ray scattering coupled with the pair distribution function. By extension, this particular synthesis route also enables us to search for rare or never reported phases that may exhibit significant electrocatalytic activity for the dissociation of water. The choice of compositional domains of interest, guided by machine learning to minimise formation energies, led to the synthesis of nanoparticles of a bimetallic boride of nickel and cobalt boron. We have also made progress in studying new synthesis routes for nickel borophosphide ternary phases, which are rare and difficult to obtain. Finally, we explored a route for synthesising metal nanoparticles without organic surface ligands, in order to avoid secondary reactions or competitive diffusion mechanisms within the metals from the ligands during molten salt synthesis. Based on work demonstrating the colloidal stability of nanomaterials in molten salts, we describe a rapid and simple method for synthesising metal nanoparticles based on molten salts using nickel as a case study
Ballouki, El Hassan. "Détermination du diagramme de viscosité ternaire NaCl-KCl-LiCl par la méthode d’écoulement." Lyon, INSA, 1986. http://www.theses.fr/1986ISAL0042.