Dissertations / Theses on the topic 'Métaux des terres rares – Toxicologie'
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Fleurbaix, Emmanuel. "Évaluation écotoxicologique des éléments terres-rares : approches cellulaires chez différentes espèces aquatiques." Electronic Thesis or Diss., Université de Lorraine, 2021. http://www.theses.fr/2021LORR0324.
Since 30 years ago, the growing use of Lanthanides in new technologies has contributed to important releases of these metals into aquatic ecosystems. In a global sustainable development policy aimed at preserving the quality of ecosystems, the impact of Lanthanides on aquatic organisms has naturally been questioned. However, studies on the aquatic ecotoxicology of Lanthanides are incomplete, and no consensus is established yet. In this context, we studied the cellular toxicity of Lanthanides individually and in mixtures. To determine these toxic effects, cell viability was measured on Danio rerio fibroblast-like cells (ZF4; ATCC®, CRL-2050™), Danio rerio hepatic cells (ZFL; ATCC®, CRL-2643™), Oncorhynchus mykiss epithelial cells (RTgill-W1; ATCC®, CRL-2523™), and primary culture of Corbicula fluminea digestive glands exposed to Lanthanides. Direct toxicity of Lanthanides has been observed on all cellular models. Concerning the toxicity of Lanthanides in mixtures, synergistic effects have been underlined on the three fish cell lines. In this research, we focused on the mechanisms of the detoxification of Lanthanides in the case of ZF4 cells from Danio rerio. The effects of Lanthanides were assessed in the presence of specific inhibitors of glutathione-S-transferases (ethacrynic acid) and MRP-like (MK571 and probenecid), by cell viability measurements. We decided to study these actors of the cellular detoxification due to their respective roles in phases II and III of the cellular detoxification of metals in fishes and bivalves. Regarding the results, MRP-like proteins are effectively involved in the detoxification of Lanthanides in ZF4 cells. Overall, our results highlighted the relevance of the toxic effects of Lanthanides at the cellular level for the risk assessment of these metals
Martin, Myriam. "Réactions d'aminolyse en catalyse et catalyse énantiosélective par des complexes de terres rares." Paris 11, 2009. http://www.theses.fr/2009PA112331.
This PhD was focused on the development of the use of rare earths in catalysis and in particular for aminolysis of functionalized meso epoxides and aziridines by aromatic amines. The samarium diiodide is used as a catalyst of Lewis acid type and we have shown that samarium diiodide catalyzes the aminolysis of functionalized epoxides in mild conditions and allowes to isolate various new aminoalcohols despite the presence of an additional heteroatom. Samarium iodo binaphtholate is an efficient catalyst for asymmetric ring opening of epoxides containing different heteroatoms by aromatic amines such as aniline, ortho- or para-anisidine. Many β-aminoalcohols containing heterocycle, not described in the literature before our study, have been isolated with enantiomeric excesses up to 71%. These catalysts were also tested in the aminolysis of activated or no activated aziridines reaction. Various 1,2-diamines have been isolated under mild conditions but with samarium iodo binaphtholate diamines were isolated with low ee in all cases. In order to increase enantiomeric excesses, we have described a synthesis for new complexes of rare earths prepared by a very simple procedure from rare earth chloride, lithium trimethylsilyl and binaphthol. These new complexes are heterobimetallic compounds and complexes of samarium, yttrium, neodymium, scandium and lanthanum were successfully isolated. The complexes of samarium and yttrium catalyzed under mild conditions the aminolysis reaction of functionalized epoxyde. The β-aminoalcohols were prepared with enantiomeric excesses up to 84% in the case of the reaction between the epoxide of 2,5-dihydrofuran and para-anisidine
Brik, Fouad. "Sur des niobates d'alcalins, d'alcalino-terreux et de terres rares : synthèse et cristallochimie, rayons X et microscopie électronique." Toulouse 3, 1994. http://www.theses.fr/1994TOU30058.
Nicolas, David. "étude d'agrégats d'oxydes de terres rares." Phd thesis, Université Claude Bernard - Lyon I, 2007. http://tel.archives-ouvertes.fr/tel-00170447.
Boyer-Candalen, Christine. "Nouveaux oxychalcogénures de terres rares et de métaux de transition (Ti, Nb) : Synthèse, étude cristallochimique et propriétés physiques." Nantes, 2000. http://www.theses.fr/2000NANT2124.
This memory reports syntheses, crystallo-chemical characterizations, and physical properties of new oxychalcogenides in the Ln/M/X/O system (Ln=rare earth; M=Ti, Nb; X=S, Se)
Duris, Fanny. "Préparation de complexes associant un cation métallique à des anions non coordinants : applications en synthèse organique." Dijon, 2002. http://www.theses.fr/2002DIJOS027.
Mahé, Nathalie. "Nouveaux précurseurs moléculaires : les complexes polynucléaires de lanthanides. Synthèses, caractérisations structurales et physico-chimiques." Rennes, INSA, 2003. http://www.theses.fr/2003ISAR0008.
Highly organized polymetallic architecture creation is crucial for development of new molecular materials that employing magnetic, optical and catalytic properties of lanthanides. Our work consisted in preparing, by a control of rare earth ion hydrolysis, polynuclear lanthanide complexes. The two first are devoted respectively to a bibliographical review of the various polynuclear rare earth systems synthesized to this day ; with the chemical ans physical properties of the lanthanide ions. The following chapters relate to the experimental parts of this work. The synthesis route is based on a hydrolysis control of lanthanide ions in solution. According to the hydrolysis rate, we obtained either non-hydroxylated coumpounds containing lanthanide ions, or rare earth hydroxysels, or finally of lanthanide hexanuclears under controlled hydrolysis conditions. The last part of this work is devoted to utilization of lanthanide hexanuclears like new molecular precursors
Feuvrie, Christophe. "Complexes métallo-organiques de métaux de transition et de terres rares pour l'optique non linéaire." Rennes 1, 2005. http://www.theses.fr/2005REN1S040.
Bertran, François. "Structure électronique et propriétés structurales de dépôts de terres rares sur métaux de transition." Nancy 1, 1992. http://docnum.univ-lorraine.fr/public/SCD_T_1992_0003_BERTRAN.pdf.
Lerat, Antoine. "Dynamique des éléments traces métalliques à l’interface ville-estuaire : métaux classiques et terres rares." Thesis, Bordeaux, 2021. http://www.theses.fr/2021BORD0005.
Control of urban pollutants is a major issue, especially in coastal areas, in a context of rapidly growing urbanization and the emission of emerging potentially highly toxic contaminants, such as Rare Earth Elements (REEs). This study is a part of the REGARD project and aims at understanding the dynamics of “conventional” trace metals (Tms) and REEs in the Jalle River, the main urban hydrosystem draining the Bordeaux Metropole and to assess its influence on the Garonne section of the Gironde estuary after having characterized two major urban sources: domestic wastewater and stormwater runoff draining the Bordeaux Highway. Due to its use as a contrast agent for MRIs and its low removal in WWTPs, gadolinium (Gd) is an excellent tracer of the domestic/hospital urban source in the Jalle River. With an annual flux estimated at 27 kg.yr-1 (23 mg.hab-1.yr-1) of dissolved Gdantrh in the Garonne River, the Bordeaux Metropole contributes nearly 25% of the Gd in the main branch of the Gironde Estuary. This flux have probably evolved like those of the Garonne at its outlet (before Bordeaux Metropole) which have doubled over the past two decades (2003: 32 kg.yr-1; 2017: 75 kg.yr-1) due to the increase in MRIs on the Garonne watershed. The high temporal analysis of a major summer rainstorm showed that the relative contributions of the daily TM fluxes of the Jalle River ranged from: 5 %(Sr) - 40%(Cu) for dissolved phases and 30% (As) – 88% (Cu) for particulate phases. The first forty minutes of the event (<17% of time) accounted for 65% of the SPM flux (and associated particulate TMs) exported by the stormwater runoff because of the first-flush of road dust. If Cu and Zn fluxes had significant contribution for the Jalle River, they are not good tracers of traffic-related source because of their ubiquitous uses. Although cerium anomalies are still weak, it should be a future good tracer with higher traffic density and technological development in catalytic converters. Using a 2-year monitoring along the Jalle continuum, this study demonstrated the upstream watershed strongly influences the geochemical composition of the Jalle River for many majors and TMs (e.g. Al, Fe, REEs) and that it contributes the bulk of dissolved TM fluxes (Al: 96%; REEs: 96 - 99%). The domestic source, via the WWTP loads, continuously affects the quality of the Jalle waters by significantly increasing dissolved Ni, Sn, Cu, Ag and Gd concentrations, mainly during low water conditions due to lower dilution by the upstream Jalle River. Conversely, the traffic-related (highway) source influences the Jalle River only more intermittently with regard to dissolved and particulate Cu, Zn, Sb during major summer rainstorm. Finally, further works on geochemical cycles of TMs at the urban-estuarine interfaces will be essential to reduce dispersion of TMs in urban systems, in order to limit impacts on natural environmental systems and to develop methods for the recovery and recycling of technology-critical elements
Rouault, Philippe. "Les matériaux intermétalliques terres rares - métaux de transition et instabilité de l'antiferromagnétisme de bande." Grenoble 1, 1989. http://www.theses.fr/1989GRE10105.
Marie, Cécile. "Synthèse et évaluation de nouvelles molécules polyfonctionnelles pour la séparation groupée des actinides." Nantes, 2009. http://www.theses.fr/2009NANT2096.
The aim of this project is to design new extracting molecules for spent nuclear fuel reprocessing. In order to minimize the long-term residual radiotoxicity of the waste, the GANEX process is an option based on homogeneous recycling of actinides. All actinides (U, Np, Pu, Am, Cm), present in a highly acidic aqueous solution, would be extracted together and separated from fission products (especially from lanthanides) using liquid‑liquid extraction. In this context, twenty new bitopic ligands constituted of a nitrogen polyaromatic unit functionalized by amide groups were synthesized. Liquid-liquid extraction tests with these ligands dissolved alone in the organic phase show that N,N,N’,N’-tetraalkyl-6,6’’(2,2’:6’,2’’‑terpyridine)-diamides are able to selectively extract actinides at different oxidation states (Np(V et VI), U(VI), Pu(IV), Am(III), Cm(III)) from an aqueous solution 3M HNO3. Nevertheless, actinides(III) are poorly extracted. According to crystallographic structures of complexes with Nd(III) and U(VI) determined by X-rays diffraction, these ligands are pentadentate. In solution (methanol), stoichiometries (1:1) of Nd(III), U(VI) and Pu(IV) complexes were determined by electrospray ionization mass spectrometry. Stability constants, evaluated by UV-visible spectrophotometry in MeOH/H2O solutions, confirm the selectivity of ligands toward actinides(III) with respect to lanthanides(III). Associate to nuclear magnetic resonance experiments and DFT calculations (Density Functional Theory), a better knowledge of their coordination mode was achieved
Mouawia, Rola. "Structuration et fonctionnalisation de matériaux hybrides organiques-inorganiques." Montpellier 2, 2007. http://www.theses.fr/2007MON20068.
Andreiadis, Eugen Sorin. "Edifices luminescents à base de lanthanides pour l'opto-électronique." Grenoble 1, 2009. http://www.theses.fr/2009GRE10050.
Luminescent lanthanide complexes are receiving a large interest for their applications in the field of optoelectronics, as a result of their pure colors and high emission efficiencies. However, the development of new lanthanide chelates for optoelectronic devices has lagged behind that of other applications, and only a limited number of architectures have been tested. The aim of this work is to access new synthetic possibilities in the area of lanthanide emitters for optoelectronics, by designing specific ligands and studying the properties of their lanthanide complexes, considering their applications for solid state devices. To achieve this aim, we have designed, synthesized and studied the complexation of lanthanides by a series of ligands based on the terpyridine-, bipyridine- and pyridine-tetrazole motifs, appended with substituents having various electronic effects. The resulting complexes have been characterized by X-ray crystallography, NMR and luminescence studies. The emission efficiencies are very high in some cases, both in the visible and in the NIR region, demonstrating the clear influence of tuning the ligand structure on the photophysical properties of the final lanthanide complexes. Furthermore, we have synthesized, characterized and tested in OLED devices a new class of neutral complexes completed by β-diketonate units. Finally, in order to explore the sensitization of lanthanide ions by d-metal complexes, we have designed and synthesized, based on our previous studies, a new specific heterometallic architecture containing iridium complexes as lanthanide antennas, and we have investigated by luminescence measurements the energy transfer processes
Belkasmi, Mohammed. "Péthographie et géochimie des granites à métaux rares." Vandoeuvre-les-Nancy, INPL, 1993. http://www.theses.fr/1993INPL087N.
Le, Meliner Maria Mendes Da Silva. "Caractérisation et valorisation de minerai de xénotime ((Y,TR) PO4) par voie hydrométallurgique." Lille 1, 1991. http://www.theses.fr/1991LIL10135.
Chour, Zeinab. "Valorisation de terres rares à partir de plantes hyperaccumulatrices." Electronic Thesis or Diss., Université de Lorraine, 2018. http://www.theses.fr/2018LORR0142.
Due to the risk of primary resource supply of rare earths and the environmental impacts generated by mining areas, the concept of agromining seems to be a very promising solution. It allows the extraction of heavy metals from polluted soils or industrial wastelands, by an environmentally friendly method, thanks to the cultivation of hyperaccumulating plants. Once the culture is completed, hydrometallurgical processes are developed in order to extract from plants the metals having a significant economic value. The present work aims to develop hydrometallurgical processes for the extraction of rare earths from a hyperaccumulator plant called Dicranopteris dichotoma. This fern is known for its high ability to accumulate rare earths, especially light ones, in its aerial part. Different extraction and separation ways of rare earths from other elements have been studied. At first, leaching of dry biomass was implemented. The leaching yields according to the nature of extracting solutions could thus be compared. For this approach, precipitation is then performed, followed by calcination step to obtain rare earth oxides. In a second approach, the leaching of dry biomass was intensified by an ion exchange process during which, the rare earths are fixed on the resin. After percolating solutions on the resin in order to eliminate impurities, an elution step leads to obtain a concentrated solution of rare earths. Finally, a third extraction process is carried out from the ashes of D. dichotoma, after a combustion step. This approach is based on an alkaline leaching of the ash allowing the elimination of soluble impurities in this medium. The residue is then dissolved, followed by rare earths selective precipitation. These three approaches studied, are actually complementary and the combination of certain steps can be promising, especially to eliminate some impurities. The study of these processes and their combination deserves to be pursued in order to improve the extraction yields and the purity of final product. It will then develop a pilot scale and industrial process
Ferté, Tom. "Dynamique ultrarapide de l'aimantation dans les alliages de métaux de transitions et de terres rares." Thesis, Strasbourg, 2017. http://www.theses.fr/2017STRAE018/document.
My PhD work describes the pico and femtosecond magnetization dynamics using the time structure of X-rays. I studied the ultrafast demagnetization of thin films (~ 20 nm) for various transitions metals (TM) - rare earths (RE) alloys. My studies have been performed by using two experimental techniques which are sensitive to the magnetization and which are time resolved: tr-XMCD and tr-MCDAD. These two experimental techniques also show chemical selectivity allowing to distinguish the TM and RE dynamics. They are both based on pump-probe experiments which were used at the SOLEIL and BESSY II synchrotrons
Lassri, Hassan. "Elaboration et études des propriétés magnétiques des rubans amorphes métaux de transitions-terres rares-métalloïdes." Rouen, 1990. http://www.theses.fr/1990ROUES001.
Whitty-Léveillé, Laurence. "Développement d'une méthode d'analyse des éléments de terres rares (ETR) par ICP-MS/MS." Master's thesis, Université Laval, 2016. http://hdl.handle.net/20.500.11794/26700.
In this work, an innovative analytical protocol is introduced for rapid measurement of rare-earth elements (REE), including Sc and Y, in geological materials. Open-vessel acid digestion, microwave digestion and alkali digestion were investigated as possible digestion methods for minerals bearing REE. A new digestion procedure was developed using a fusion apparatus. The high digestion temperature (1050 ºC) and the use of LiBO2 as a flux were found to be effective for the digestion of every REE. Instrumental neutron activation analysis (NAA), microwave induced plasma atomic emission spectroscopy (MP-AES), inductively coupled plasma optical emission spectroscopy (ICP-OES), and inductively coupled plasma mass spectrometry (ICP-MS) were explored as possible analytical techniques for the measurement of REE in various mineral samples. The comparative study showed that the results obtained by ICP-MS are in good agreement with the certified reference materials (CRM) data, whereas the other analytical techniques reveal several spectral interferences for some REE. Furthermore, the tandem quadrupole instrument enables new mass filtering configurations, which can reduce polyatomic interferences during the determination of Sc in mineral matrices. Conversion of Sc+ ions into ScO+ ions provided interference-free conditions and sufficiently low limits of detection, down to 3 ng/L, to accurately quantify Sc. The accuracy of the proposed methodology was assessed by analyzing five different CRM (BX-N, OKA-2, NIM-L, SY-3 and GH).
Estrade, Guillaume. "Le complexe cénozoïque alcalin d'Ambohimirahavavy à Madagascar : origine, évolution et minéralisations en métaux rares." Toulouse 3, 2014. http://thesesups.ups-tlse.fr/2583/.
This thesis focuses on the Oligo-Miocene Ambohimirahavavy alkaline complex, in Northwestern Madagascar. Its objective is to investigate the formation of this complex, in particular, to understand the formation of the associated rare-metal mineralization (Zr, Nb, Ta, Th, U and the rare earth elements). It will be shown that the complex formed through magmatic differentiation of mantle-derived magmas that, upon ascent, evolved to SiO2 undersaturated and SiO2 oversaturated varieties by crustal contamination. Finally, a strongly peralkaline composition evolved from the most differentiated magma, at oxygen fugacity conditions opposite from those recorded for the less differentiated units. The rare-metal mineralization is mainly associated with the oversaturated rocks, i. E. , the peralkaline granites and pegmatite dykes. Two main types of mineralization could be identified, one, miaskitic, characterized by several generations of zircon, and one, agpaitic, consisting mainly of eudialyte. Both types of mineralization formed from a combination of magmatic and hydrothermal processes. An early enrichment stage took place by primary magmatic processes, mainly due to extreme differentiation which led to the formation of volatile-rich peralkaline granitic melts. The rare metals deposited during this stage were remobilized and redistributed during hydrothermal alteration caused by orthomagmatic fluids. These exsolved during the final stages of crystallization, caused extensive pseudomorphism of primary rare-metals bearing minerals and redistributed the rare metals within the intrusives as well as in the host rock, mostly in the form of skarn-like mineralization, which partly involved also meteoric fluids. U-Pb dating of secondary zircons shows ages 3 Ma younger than those obtained by the same method on the syenites, confirming the hydrothermal origin of the zircons. This study highlights the complex processes involved in the formation of peralkaline granites and pegmatites and the diversity of mineralization types associated with these rocks. The proposed model can be used as an exploration tool and can help determining potential drilling targets in the undersaturated units of the complex
Dechaud, Henri. "Développements méthodologiques en immunoanalyse : immunodosages par fluorimétrie à résolution temporelle utilisant des chélates de lanthanides comme marqueurs." Lyon 1, 1991. http://www.theses.fr/1991LYO1W272.
Camus, Elise. "Polymères amphiphiles à usage biomédical synthétisés à partir d'un squelette SEBS : styrène-éthylène-butylène-styrène : polymérisation stéréospécifique du styrène catalysée par des complexes allyllanthanidiques." Dijon, 2000. http://www.theses.fr/2000DIJOS080.
Bonnet, Fanny. "Synthèse de nouveaux complexes organométalliques de terres rares, Samarium et Néodyme, pour la polymérisation et la copolymérisation des diènes avec des oléfines et des monomères polaires." Dijon, 2003. http://www.theses.fr/2003DIJOS026.
With an ansa samarocene complex it was possible to synthesis copolymers of dienes with a-olefines of various lengths. We studied the influence of the chain length of the olefin inserted on the physical-chemical properties. Functional copolymers were also obatined by the use of a,w-dienes as comonomers (octa-1,7-diene, hexa-1,5-diene), and by the insertion of only one double bond in the polydiene chain. With the same complex we were able to elaborate block copolymers of dienes with polar monomers (e-caprolactone, methyl methacrylate), and we have shown that these copolymers were efficient compatibilisers in polar and non polar polymer blends. A new family of rare earth hemimetallocene complexes was then developped. Samarium and Neodymium complexes were synthesised by the use of chloride and borohydride precursors, with a cyclopentadienyl ligand close to the permethylcyclopentadienyl one (Cp*'), with the general formula Cp*'Ln X2 (THF)n, X=BH4, Cl. By substitution of one X ligand by a diiminate one (NN), we could isolate genuine heteroleptic complexes Cp*'Ln X (NN). These new complexes, in the presence of MgR2 as co-activator, are efficient catalysts for the polymerisation of dienes with a trans specificity up to 98. 9% in the case of the borohydride ones, this result gives some outlooks for the copolymerisation with olefins
Eckes, Fabrice. "Dispositifs luminescents à base de porphyrines et de lanthanides." Strasbourg, 2009. http://www.theses.fr/2009STRA6220.
Lanthanides possess unique photophysical properties requiring the population of excited states that can only be accessed with difficulty via a direct pathway. This issue can be overcome by using a compound with a high molar extinction coefficient which can sensitize the lanthanide ion. This monograph describes the three successive steps leading to the photophysical study of luminescent complexes. The first chapter presents the synthesis of the ligands made of two or four 8-hydroxyquinoline moieties linked to a porphyrin core. The arrangement of these coordinating arms with respect to the porphyrin is controlled by the nature of the starting atropoisomer. The synthetic pathways involving different protecting groups and coupling methods are detailed as well as X-ray diffraction analysis of several protected intermediates. The second chapter describes the selective metallation of the ditopic ligands. The porphyrin is metallated by a d transition metal and a lanthanide ion is selectively coordinated to the four 8-hydroxyquinolin moieties. The third chapter presents the photophysical studies of Neodymium and Palladium-Neodymium complexes. In both cases, an energetic transfer from a porphyrin absorbing in the visible region to a Lanthanide emitting in the Near Infra Red is evidenced as well as a dependence of its efficiency depending on the presence of the Palladium in the porphyrin core
Labille, Jérôme. "Déstabilisation d'une suspension colloi͏̈dale de montmorillonite par coagulation-floculation, en présence de polysaccharides." Vandoeuvre-les-Nancy, INPL, 2003. http://www.theses.fr/2003INPL021N.
Carette, Pierre. "Spectroscopie des monoxydes de lanthanides." Grenoble 2 : ANRT, 1987. http://catalogue.bnf.fr/ark:/12148/cb37603617g.
Calvez, Guillaume. "Synthèse et étude des applications potentielles de matériaux moléculaires à base d'entités hexanucléaires de terres rares." Rennes, INSA, 2009. http://www.theses.fr/2009ISAR0024.
Coordination polymers are infinite compounds made up of metallic centres bound to one another by organic ligands. Rare-earth-based coordination polymers broaden the application field of this kind of compounds thanks to the exceptional magnetic and optic properties of rare earth ions. The goal of the works achieved during this PhD was to be able to use a rare-earth-based polynuclear entity –the octahedral rare earth based hexanuclear entity– as a metallic centre in coordination polymers. The reactivity of the complex has been a problem resulting either in an alteration or in a non-reaction of the octahedral hexanuclear entity. A solution to this problem has been the solvothermal synthesis, which makes it possible to have the complex react in a medium which is less aggressive towards it. A coordination polymer has been obtained and characterised, several proofs show with certainty that it is a coordination polymer containing octahedral hexanuclear entities as metallic centres
Daran, Emmanuelle. "CaF2:Er épitaxié par jets moléculaires : propriétés optiques en relation avec les paramètres d'élaboration." Toulouse, INSA, 1994. http://www.theses.fr/1994ISAT0005.
Chour, Zeinab. "Valorisation de terres rares à partir de plantes hyperaccumulatrices." Thesis, Université de Lorraine, 2018. http://www.theses.fr/2018LORR0142/document.
Due to the risk of primary resource supply of rare earths and the environmental impacts generated by mining areas, the concept of agromining seems to be a very promising solution. It allows the extraction of heavy metals from polluted soils or industrial wastelands, by an environmentally friendly method, thanks to the cultivation of hyperaccumulating plants. Once the culture is completed, hydrometallurgical processes are developed in order to extract from plants the metals having a significant economic value. The present work aims to develop hydrometallurgical processes for the extraction of rare earths from a hyperaccumulator plant called Dicranopteris dichotoma. This fern is known for its high ability to accumulate rare earths, especially light ones, in its aerial part. Different extraction and separation ways of rare earths from other elements have been studied. At first, leaching of dry biomass was implemented. The leaching yields according to the nature of extracting solutions could thus be compared. For this approach, precipitation is then performed, followed by calcination step to obtain rare earth oxides. In a second approach, the leaching of dry biomass was intensified by an ion exchange process during which, the rare earths are fixed on the resin. After percolating solutions on the resin in order to eliminate impurities, an elution step leads to obtain a concentrated solution of rare earths. Finally, a third extraction process is carried out from the ashes of D. dichotoma, after a combustion step. This approach is based on an alkaline leaching of the ash allowing the elimination of soluble impurities in this medium. The residue is then dissolved, followed by rare earths selective precipitation. These three approaches studied, are actually complementary and the combination of certain steps can be promising, especially to eliminate some impurities. The study of these processes and their combination deserves to be pursued in order to improve the extraction yields and the purity of final product. It will then develop a pilot scale and industrial process
Monteil, Vincent. "Synthèse de copolymères du butadiène et des oléfines par des catalyseurs à base de terres rares." Lyon 1, 2002. http://www.theses.fr/2002LYO10137.
Touchard, Virginie. "Catalyseurs à base de lanthanides ou d'yttrium pour la polymérisation cationique en milieu organique et en miniémulsion." Lyon 1, 2003. http://www.theses.fr/2003LYO10268.
Thuilliez, Julien. "Synthèse de métallocènes de néodyme pour la copolymérisation des oléfines et du butadiène." Lyon 1, 2005. http://www.theses.fr/2005LYO10199.
Marrot, Florent. "Etude des malonates et squarates de lanthanoi͏̈de comme précurseurs des sulfures et oxysulfures correspondants." Toulouse 3, 1994. http://www.theses.fr/1994TOU30207.
Lannou, Marie-Isabelle. "Le mischmétal : évaluation en tant que réducteur et dans la préparation de complexes utilisables pour la catalyse de réactions organiques." Paris 11, 2002. http://www.theses.fr/2002PA112237.
Mischmetall is an alloy of light lanthanides coming from a mineral called Bastnoesite. Its composition is as follow: cerium 50%, lanthanum 33%, neodymium 12%, praseodinium 4%, others lanthanides 1%. The efficiency of mischmetall and its derivatives has been investigated in a wide range of organic reactions. The use of samarium diiodide in catalytic amounts together with mischmetal as coreductant allows the Barbier and Grignard-type benzylation and allylation of a variety of carbonyl compounds (aldehyde, ketones, esters, lactones). A catalytic scheme is proposed to account for the results. The mischmetall/SmI2(cat) system has also been used in alkylation of esters and lactones. Reactions on five or six-membered ring lactones do not take place in the absence of a catalytic amount of nickel diiodide (with respect to samarium diiodide), whereas reactions on esters or unstrained lactones do not require the presence of this salt. A explanation that takes into account the part of nickel diiodide is proposed. Reformatsky-type reactions between ketones and α-bromoesters have been efficiently performed using either the mischmetal/SmI2(cat) system or mischmetal activated by a catalytic amount of diiodoethane. β-hydroxyesters have been obtained in medium to good yields. Preparation of hydrated lanthanides trichlorides and triflates has been carried out directly from mischmetal leading to expected complexes in excellent yields. Interestingly, synthesis of anhydrous THF adducts lanthanides halides (X = Cl, Br, I) has been performed in one step starting from pure lanthanide metals and from mischmetal. Complexes prepared from the alloy have exhibited a high reactivity as well in reactions involving stoechiometric amounts of lanthanides salts (Luche and Imamoto-type reaction) as in reactions involving catalytic amounts of lanthanide salts such as Biginelli reaction, Meerwein-Pondorff-Verley reduction, Oppenauer oxidation or Mukaiyama-type aldolisation on sylyl enol ethers derivatives
Gadzuric, Slobodan G. "Etude expérimentale des propriétés thermodynamiques, de transport et structurales de systèmes de bromures de lanthanidesPrédiction par méthodes statistiques de data mining." Aix-Marseille 1, 2006. http://www.theses.fr/2006AIX11017.
Phase diagrams of 8 systems were determined (CeBr3-MBr and EuBr2-MBr, M=Li, Na, K, Rb), heat capacity of corresponding stoichometric compounds in the EuBr2-MBr and liquid mixing enthalpies of bromide europium(II) systems were measured. Raman spectra of pure EuBr2 and reflectance spectra of some lanthanide bromide – alkali bromide mixtures were performed. Electrical conductivity experiments were determined for all alkali bromide mixtures with LaBr3, NdBr3 and EuBr2. Using two mathematical techniques (Partial Least Square and Principal Component Analysis) by careful selection of thermodynamic properties for the set of lanthanide halides investigated in our laboratory, still unknown values of some basic thermodynamic functions (ΔHform and ΔGform) for the set of 14 different lanthanide halides were predicted with high accuracy
Oudahmane, Abdelghani. "Caractérisations structurales et optiques de polyphosphates de formule ALn(PO3)4 (A=alcalins, TI ; Ln=terres rares)." Clermont-Ferrand 2, 2010. http://www.theses.fr/2010CLF22034.
Rodrigues, Anne-Sophie. "Group 3 allyl ansa-metallocene complexes for styrene (co)polymerization catalysis." Rennes 1, 2007. http://www.theses.fr/2007REN1S063.
Une famille de nouveaux complexes allyles ansa-métallocènes du groupe 3 et des lanthanides a été synthétisée et caractérisée par RMN et diffraction des rayons X. Les performances des ces catalyseurs mono-sites en homo- et copolymérisation du styrène ont été étudiées. Les complexes cyclopentadiényle-fluorényle ont démontré un bon contrôle et une très haute stéréosélectivité pour la production de polystyrène syndiotactique alors que les complexes bis(indényles) produisent eux du polystyrène hautement isotactique. L’influence de la structure de ces complexes sur l’activité et la sélectivité a ainsi été mise en évidence. D’autre part, ces catalyseurs ont permis la synthèse de nouveaux matériaux polymères originaux par copolymérisation du styrène avec de l’éthylène et/ou de l’isoprène. Quelques propriétés thermiques et mécaniques de ces copolymères riches en styrène ont été évaluées et suggèrent des applications prometteuses
Iezid, Mostepha. "Propriétés physiques et mise en œuvre des verres à base d’oxydes lourds." Rennes 1, 2012. http://www.theses.fr/2012REN1S164.
This work concerns the synthesis and the characterization of new glasses in the Sb₂O₃ – CdCl₂ – SrCl₂ system. Quaternary systems were obtained by partial substitution of SrCl2 by elements of groups IA and IIA and CdCl₂ with ZnCl₂. The vitreous domains were enlarged and stability increases for antimony-rich compositions. Physicochemical characterizations were implemented using various techniques. The evolution of stability, mechanical and thermo mechanical properties were interpreted on the basis of a structural model specific to antimonite glass. This model was discussed again to account for the NMR MAS ¹¹³Cd results. The Sb₂O₃ – CdCl₂ matrix was doped with trivalent lanthanides and several excitation and emission spectra were reported
Branco, Joaquim Miguel Badalo. "Contribution à la valorisation de composés intermétalliques nickel- et cuivre-terres rares en catalyse d'hydrogénation." Toulouse 3, 1994. http://www.theses.fr/1994TOU30094.
Boutarek, Nai͏̈ma. "Contribution à l'étude des silico-germaniures des métaux de transition 3d et des terres rares (Ce, Pr)." Grenoble INPG, 1992. http://www.theses.fr/1992INPG0150.
Cheisson, Thibault. "Synthèse et réactivité de complexes à ligand iminophosphorane : des métaux de transition aux actinides." Palaiseau, Ecole polytechnique, 2015. https://theses.hal.science/tel-01245256/document.
Rubin, Jacques. "Etude de la dynamique des transferts d'énergie et des fluorescences dans un matériau laser à solide émettant dans l'infra-rouge : le monocristal YLiF4 dopé aux ions terres rares erbium, thullium et holmium." Lyon 1, 1987. http://www.theses.fr/1987LYO10128.
Dehaine, Quentin. "Récupération des Terres Rares (La, Ce, Nd) et métaux rares (Sn, Nb, W) à partir de résidus micacés issus de la production de kaolin." Thesis, Université de Lorraine, 2016. http://www.theses.fr/2016LORR0019.
Rare metals granites have always been considered of poor economic value due to their low metal grades but, when altered, they are often exploited for their industrial minerals. This work address the recovery of critical metals (CRMs) including Light Rare Earth Elements (LREE) and rare metals (Sn, Nb, W) from St Austell (UK) kaolin residues though the development of a beneficiation process. Results shows that CRMs are pre-concentrated in the micaceous residue stream with LREE grades of 170 ppm, which account from 40% to 60% of the mass of CRM entering the plant. Analysis of this residue streams shows a high variability of CRM grades and suggest a cut-off grades for some of them. A combined gravity/flotation process have been developed for this residue which allow to recover up to 60% LREE with LREE grade of 1.6 to 0.5% for the gravity and flotation concentrate respectively
Rousseau, Nicolas. "Epitaxie par jets moléculaires de nitrure de gallium sopé terres rares : caractérisation structurale et optique." Montpellier 2, 2003. http://www.theses.fr/2003MON20154.
Rochette, Julie. "Optimisation d'une méthode d'extraction acide des éléments de terres rares (ÉTR) dans les résidus de bauxite." Master's thesis, Université Laval, 2018. http://hdl.handle.net/20.500.11794/30274.
The rare earth elements (REE) are minerals presents in a growing number of new technologies. The REE are composed of 16 elements. They are the lanthanides (elements 57 to 71 from periodic table) with the scandium and yttrium. Despite their names, these elements are not so rare. However, they are scattered throughout the earth crust and found in small quantities. Unfortunately, the production of the REE using ores such as monazite has significant environmental impacts since it is producing large quantities of wastes which some are radioactive. New alternative sources are now considered to minimize the environmental impact on the REE exploitation. Among the resources, the mining residues from the production of alumina (bauxite residues or red mud) are an interesting option. The red mud from the Bayer’s process contain mainly iron and alumina but also some thorium, uranium and REE. The objective of this work is to develop an acid based leaching method to perform the selective extraction of REE while minimizing the solubilisation extraction of matrix elements of the bauxite residues (BR). First, a complete digestion of the BR was done to determine the concentration of the constituting elements. Then, leaching experiments with diluted acids (hydrochloric, nitric and sulfuric) were done at different pH, temperatures and heating times. The REE and the radioactive elements were analysed by ICP-MS/MS whereas the matrix elements were analysed by ICP-OES. To simplify the investigation of the various solubilisation conditions, a statistical method was used e.g. the factorial design. This method enables the study of several parameters simultaneously and identifies the interconnectivity of the parameters. During the leaching investigation, a suitable percentage of REE were extracted over the other constituents of the matrix. After that, a liquid-liquid extraction with a diglycolamide ligand and a co-precipitation were done the separate the REE from the co-leached constituents of the matrix.
Dousseau, Philippe. "Etude du pompage longitudinal par diode laser du yag dope holmium et thulium." Toulouse 3, 1992. http://www.theses.fr/1992TOU30046.
Pernel, Carole. "Comportement électrochimique de l'américium dans l'eutectique LiCl-KCl fondu en vue de sa séparation des lanthanides par électrodéposition." Grenoble INPG, 2002. http://www.theses.fr/2002INPG0008.
Isnard, Olivier. "Rôle des éléments interstitiels sur les alliages pour aimants permanents à base d'éléments de terre rare et de fer : synthèse, étude structurale, analyse spectroscopique en relation avec les propriétés magnétiques." Université Joseph Fourier (Grenoble), 1993. http://www.theses.fr/1993GRE10209.
Le, Polles Ghislaine. "Elaboration de nouveaux matériaux : les pigments rouges à base de terres rares pour céramique de haute température : Les phosphates de cuivre de type nasicon pour applications en tant que catalyseurs ou luminophores." Bordeaux 1, 1987. http://www.theses.fr/1987BOR10570.