Dissertations / Theses on the topic 'Titane – Composés – Propriétés physico-chimiques'
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Benyahia-Bentadjine, Sonia. "Mécanismes de formation et propriétés physico-chimiques et mécaniques des interphases epoxy-diamine/métal." Lyon, INSA, 2000. http://www.theses.fr/2000ISAL0025.
The interfacial reactivity between epoxy (DGEBA) and diamine (IPD) monomers and metallic substrates (titanium, aluminum and gold) has been studied using various analytical techniques. Chemical, physical and mechanical properties of organic coatings were determined as a function of their thickness and compared to bulk values. An interphase having specific properties and quite different to polymer bulks ones was underlined. Interphase properties were found to be affected by the substrate nature, metallic surface treatments, the diamine nature (whether aromatic, aliphatic or cycloaliphatic) and the stoechiometric ratio of epoxy-amine mixture. Reaction mechanisms leading to the interphase formation were determined by studying "modified" monomers by hydrated oxide layer. It was found that the diamine monomer reacts with the metallic surface and induces a chemical etching. Then metallic ions then diffuse through the organic layer to form metal-amine complexes. When a saturation threshold was reached, crystals of modified monomers were observed at room temperature. These complexes induce phase separation during the cure cycle of the epoxydiamine mixture leading to a new network formation. The understanding of these phenomena, allows us to produce bulk materials having the same properties than thin films or interphase
Guillot, Jérôme. "Couches minces d'oxynitrure de titane : la réactivité comme moyen original de caractérisation physico - chimique." Phd thesis, Université de Bourgogne, 2002. http://tel.archives-ouvertes.fr/tel-00101455.
L'objectif de ce travail était la détermination de la composition et de la structure des couches minces de TiNxOy de façon à en comprendre les propriétés électriques. Cependant, cette étude s'est rapidement avérée plus complexe que prévue, les techniques de caractérisation classiques (MEB, DRX, Raman, XPS...) étant insuffisantes pour décrire le système TiNxOy dans sa totalité. En effet, une seule phase cristallisée, isomorphe de TiN, a pu être mise en évidence dans les échantillons élaborés à haute température (T > 550 °C) tandis que des analyses quantitatives ont révélé des proportions d'oxygène relativement importantes dans tous les échantillons. Aussi, cette étude a été élargie à des films de TiN afin de comprendre l'importance de l'oxygène dans cette structure.
Des méthodes de caractérisation originales, basées sur le fait qu'il est possible de relier la structure d'un matériau à sa réactivité, ont alors été mises en œuvre afin de compléter les analyses précédentes. Notamment, l'étude de la réactivité des couches minces vis-à-vis d'une irradiation ionique ou lors de traitements thermiques a permis de qualifier et quantifier les différentes phases des films minces de TiNxOy en réalité constitués d'une phase Ti(N,O) conductrice et d'une phase TiO2 isolante. Un modèle de percolation permettant la simulation des variations de conductivité des films à partir des proportions relatives de chacune de ces deux phases a alors pu être proposé.
Mangold, Lucas. "Étude multi-techniques et multi-échelles de la spéciation du titane(IV) dans l’acide phosphorique concentré." Electronic Thesis or Diss., Université de Lorraine, 2022. http://www.theses.fr/2022LORR0025.
The conventional wet-process of production of phosphoric acid consists of a leaching of phosphate ores with sulfuric acid during which several impurities (metallic, sulfate, chloride are dissolved concomitantly. Phosphoric acid and phosphate salts are used in various applications such as fertilizers, food additives, electronic etching agent or pharmaceutical excipients and must therefore meet appropriate of specifications regarding their purity. As a consequence, the concentration of these impurities must be reduced by performing purification steps. At the industrial scale, the purification of phosphoric acid is performed mainly by liquid-liquid extraction. The operation consists in extracting as selectively as possible the phosphoric acid molecules initially contained in the leaching juice into an appropriate organic phase. However this process is not selective enough and some of the impurities are co-extracted. This leads to the necessity of performing additional purification steps to meet the requested specifications, which increases both the complexity of the global treatment and its cost. The knowledge of the speciation of impurities in concentrated phosphoric acid is essential to understand the physicochemical reasons for their co-extraction and, in fine, to design more selective extraction solvents. For example, the solvents presently used for the purification of H₃PO₄ are not selective enough against titanium(IV). Thus, this PhD thesis work aims at characterizing the speciation of this metal in a large range of phosphoric acid concentration, in order to identify subsequently the equilibria responsible for its co-extraction with H₃PO₄. This thesis is based on an original approach combining the use of spectroscopic and molecular modeling techniques. Synthetic solutions containing both titanium(IV) and phosphoric acid have been characterized using different spectroscopic techniques including UV-Visible, Nuclear Magnetic Resonance (³¹P NMR) and X-Ray Absorption (XAS) spectroscopies. Thus, the structure of the complexes formed in phosphoric acid has been studied by comparing UV-Visible spectra and calculations implementing time-dependent density functional theory (TD-DFT). The nuclearity of these complexes has also been estimated by comparing the values of the self-diffusion coefficients determined experimentally by ³¹P NMR with the values calculated by molecular dynamics for different species of titanium (IV) potentially present in solution. The coordination of titanium (IV) was also studied by analyzing the EXAFS (Extended X-Ray Absorption Fine Structure) spectra using ab-initio molecular dynamics simulations explicitly taking into account the solvation of the complexes.Finally, UV-Visible spectral data have been analyzed by a chemometric approach, based on a principal component analysis (PCA), allowing us to extract quantitative information about the distribution of the complex species identified in concentrated phosphoric acid. From all these results, it was possible to propose for the first time a diagram of speciation of titanium (IV) in phosphoric acid for a range of concentrations between 6 and 13 mol.L⁻¹, underlining the evolutionary presence of three mono- and poly-nuclear titanium (IV) complexes, the predominant species of which is [Ti(OH)(H₃PO₄)₂(H₂PO₄)]²⁺
Termoss, Hussein. "Préparation de revêtements de nitrure de bore (BN) par voie polymère précéramique : étude des paramètres d’élaboration : caractérisations physico-chimiques." Thesis, Lyon 1, 2009. http://www.theses.fr/2009LYO10145/document.
The aim of this work was to prepare boron nitride coatings onto different substrates using the Polymers Derived Ceramics (PDCs) approach. In that way, BN coatings were obtained onto graphite, pure silica and metal especially titanium. The first part of this thesis was to study parameters (of the solution used and of the dip-coating process), to obtain the best coatings in terms of morphology, cristallinity and chemical composition. The second part was dedicated to BN coatings obtained onto metal substrates using an alternative thermal treatment allowing the polymer-to-ceramic conversion without any damage for the metal. Actually, annealing by infrared irradiation allows heating only the coating, energy being reflected by the metal
Le, Goff Xavier. "Elaboration et étude des propriétés physico - chimiques de nouveaux composés magnétiques." Phd thesis, Université Sciences et Technologies - Bordeaux I, 2006. http://tel.archives-ouvertes.fr/tel-00811528.
Durand, Morgan. "Propriétés physico-chimiques, fonctionnelles et applicatives des éthers courts d’isosorbide." Thesis, Lille 1, 2010. http://www.theses.fr/2010LIL10196/document.
In the last past years, an increasing awareness of the hazards linked to the use of solvents has strengthened the regulation and forced to optimize their use. This evolution entailed an increasing interest for bio-solvents, i.e. solvents from renewable materials and with good health and environmental properties. In this context, isosorbide, a diol obtained by the double deshydratation of sorbitol, might be valuable synthon for the design of a wide range of molecules and polymers. The short isosorbide diethers (_ 5 carbones per alkyl chain), as they are biosourced and liquid at ambient temperature, are potentialy promising solvents, that is why they have been studied. The monomethyl isosorbides (-endo et -exo forms) have also been evaluated, as they are the main impurities of the commercial dimethyl isosorbide (DMI), the most promising compound of this solvents family. The physicochemical, functional and applicative properties that are necessary to the characterization and the use of new solvents have been assessed : the thermo-physical properties (vapor pressure, vaporization enthalpy), the optical and electrical properties (refractive index, dielectric constant, dipole moment), the functional properties (viscosity, partition coefficient, Kamlet et Taft solvatochromic parameters) have been measured. The environmental, health and safety profile of DMI has been determined and compared to common solvents, allowing the evaluation of its "greenness". As DMI is fully miscible with water, its physicochemical properties in aqueous solutions have been studied as well, and have enlightened a self-aggregation of DMI within a large concentration range.A solvent design process has then been developped in order to estimate the potential use of these new solvents. A novel approach for the classification of solvents has been proposed, based solely on the solvent molecular structure and relying on the "COnductor-like Screening MOdel for Real Solvents" (COSMO-RS) in which solvents are considered in their liquid state. This approach has allowed the classification of 152 solvents into 10 classes without requiring the knowledge of any experimental data. The approach has been applied to DMI and allowed to find some potential applications that have been evaluated, among which the use of DMI as fluxing agent for bitumen composition, coalescing agent for water-borne paints, solvent for paint strippers, solvent for ink removal, or coupling agent for the formulation of liquid detergents
Ramaroson, Jocelyn. "Calcination des sédiments de drapage contaminés : études des propriétés physico-chimiques." Lyon, INSA, 2008. http://theses.insa-lyon.fr/publication/2008ISAL0010/these.pdf.
The work presented deals with the NOVOSOL ® process developed by SOL V A Y S. A. Company. This aim to decompose the organics and stabilize heavy metal containing contaminated dredged sediment for beneficiai reuse. This process comprises two stages: chemical treatment (addition of soluble phosphate) and the thermal treatment (calcination). Research presented is focused on the thermal treatment. Our objective is to understand the physicochemical behaviour of the sediment during the calcination. The understanding of the evolution on these properties will help for the beneficial reuse of the treated sediment in various industry such as the civil engineering. The characterization performed was followed by the investigation of the behaviour of heavy metals and the organic compounds during the calcination. The distribution of heavy metals between the solid phase and the gas phase were studied during the calcination and the result obtained showed majority of heavy metals are trapped in the solid. The leaching tests performed showed that heavy metals present in the residue are well stabilized. The degradation of the organic compounds is effective at 400°C. Afterwards, the structural change of the sediment during thermal treatment was investigated at laboratory scale and at pilot scale. An increase in specifie surface is observed until 400°C followed by a signification reduction accompanied by a densification and growing of the particles. The increase in specifie surface observed is the formation of pores observed by due to the decomposition of organics from 400°C to l000°C. The combined evolutions of properties are due to the thermal sintering of the sediments induced by the formation of grain boundary driven by the mass transport at high temperature. The calcination in a rotary kiln showed that the physical properties (the specifie surface, density, particle size) of the sediment depend on the calcination. Parameters such as the residence time, calcination temperature, sediment flow rate were investigated
Salmaoui, Samiha. "Elaboration d'oxydes de tungstène nanostructurés, caractérisation et étude de leurs propriétés physico-chimiques." Paris 7, 2014. http://www.theses.fr/2014PA077198.
Hexagonal WO3 nanorods, hexagonal WO3. 1/3H2O nanofibers and orthohombic WO3. 1/3H2O three-dimensional hierarchical architectures have been synthesized by hydrothermal process using structure-directing templates. The structure, the morphology and the composition of the materials have been examined by different physico-chemical techniques. The effects of experimental conditions such as pH, temperature, reaction time and organic templates have been studied. Cyclic voltammetric characterization of thin films of as-prepared nanomaterials has revealed reversible lithium intercalation/deintercalation into the crystal lattice of nanocristalline tungstene oxides. A correlation between structural, morphological and electrochimical properties has been investigated. Moreover, the Hexagonal WO3 nanorods can be applied as active support for the catalytic bi-metallic Pt-Ru nanoparticles during electro-oxidation of ethanol in acid medium
Orliac, Aurélie. "Synthèse et propriétés physico-chimiques des fluoro-pipéridines XtalFluor-E et synthèse d’amides." Paris 6, 2013. http://www.theses.fr/2013PA066503.
The development of new biologically active molecules with few side effects is an important challenge. Among all the existing strategies to modulate the pharmacokinetics properties of molecules, introducing one or more fluorine atoms is often used by medicinal chemists. As the 3-aminopiperidine motif is frequently encountered in biologically active compounds, we have studied the modulation of the physico-chemical properties induced by the introduction of one or two fluorine atoms on 3-aminopiperidine motif. The synthesis of 3-amino-5-fluoropiperidines and 3-amino-5,5-difluoropiperidines was efficiently performed by ring enlargement of prolinols. The study of the pKa and the lipophilicity (log D and log P) of these fluoropiperidines was useful to quantify the effect of fluorine atom on the physico-chemical properties of 3-aminopiperidines. Besides, the synthesis of fluorinated piperidine heterocycles with biological activities, such as quinolizidines, was realized by ring enlargement induced by DAST. Among the widespread synthetic reactions, the formation of amides is an important step. For our part, we have developed the formation of amides from amines and carboxylic acids activated by XtalFluor-E. Various amines (primary and secondary) as well as various carboxylic acids can be coupled thanks to this agent. Particular conditions were also developed in order to favor the amidification between low nucleophilic amines and various carboxylic acids
Heck, Romain. "Synthèse et étude des propriétés physico-chimiques de nouvelles métallo-cyclodextrines." Nancy 1, 2003. http://www.theses.fr/2003NAN10165.
This work deals with two aspects of the study of new Metallocyclodextrins. First of all, the "phosphine-imide" reaction was generalised to the synthesis of a new family of multichromophoric and multicomplexant supramolecular podands : URFT urei͏̈docyclodextrins (URFT = Upper Rim Fully Tethered) and URFT thiourei͏̈docyclodextrins. Moreover, a new fast and reproducible synthesis of symmetrically trifunctionnalised a-cyclodextrin was developed. Second of all, specific physicochemical properties related to selective metal coordination and complexation and to fluorescence properties of URFT urei͏̈docyclodextrins "rare earth" complexes were investigated. The new systems were found to have very selective and original coordination processes towards transition metals cations. "Rare earth" complexes fluorescence emission was found to be highly sensitive towards the presence of transition metals cations and small organic molecules
Péruchon, Laure. "Caractérisations des propriétés photocatalytiques des verres autonettoyants - corrélation entre paramètres physico-chimiques et activité photocatalytique." Lyon 1, 2007. https://tel.archives-ouvertes.fr/tel-00453175.
Glass is widely used material and especially in constructions. Since 2001, self-cleaning glasses have been launched on the European market. These glasses are based on the photocatalytic property of a submicronic layer of TiO2 deposited on their surface. Under UV-irradiation, TiO2 reacts with the oxygen and water molecules present in the atmosphere to produce free radicals. These radicals are able to degrade organic stains adsorbed on the glass surface. The present work is aimed at a better understanding of the interactions between TiO2 layer and real stains, as well as the photocatalytic physicochemical mechanisms implicated. The influence of different parameters on the self-cleaning glass efficiency has been studied. The photocatalytic degradation of different pollutant families was followed to correlate the nature of the organic compounds to their degradability
Mutelet, Fabrice. "Application des méthodes chromatographiques pour caractériser les propriétés physico-chimiques de composés peu volatiles." Metz, 2001. http://docnum.univ-lorraine.fr/public/UPV-M/Theses/2001/Mutelet.Fabrice.SMZ0115.pdf.
In this work, we propose new predictive methods to represent physico-chemical properties of nonvolatile organic compounds. The experimental studies of these compounds are difficult because their normal boiling point is high and it is situated beyond the limits of their thermal stability. Consequently, their properties are generally badly known and estimated from various predictive methods. We used for the prediction purpose the method “Linear Solvation Energy Relationship” (LSER). This method widely used in organic chemistry and pharmacology was applied for the first time to the predictive calculations in the field of the chemical engineering. The application of the LSER approach involves two aspects : the first one is the modeling of the physico-chemical properties in terms of LSER descriptors and the second is the experimental determination of descriptors. It is necessary to underline that in the case of nonvolatile compounds the determination of descriptors required the implementation of new experimental methods. In the second part of this report, we present results of applications of the LSER model to the thermodynamics of fluids. The estimation of physico-chemical properties of organic compounds such as the normal boiling point and the critical properties is concerned. Correlation of cubic equation of state parameters is also dealt with. It was demonstrated that LSER model is a useful tool for implementation of predictive methods in the field of physical-chemistry and chemical engineering
Girard, Pauline. "Elaboration et études physico-chimiques de nanomatériaux moléculaires et hybrides aux propriétés photochromes et magnétiques." Thesis, Nantes, 2016. http://www.theses.fr/2016NANT4021/document.
The aim of this PhD work deals with the development and the photophysical and physico-chemical studies of magnetic and photoswitchable hybrid nanosystems. The association of these two properties appears relevant in the field of data storage, relying on the modulation of magnetisation or optical characteristics of the employed materials. Novel photochromic azo derivatives, capable of complexing metal oxides, have been synthesized. After detailed studies of their structural and photophysical properties, they have been associated to superparamagnetic iron oxide nanoparticles to yield hybrid nanoassemblies displaying two kinds of architectures. The first structure is built by grafting the azo derivatives at the surface of iron oxide nanoparticles while the second architecture, called as reverse one, involves the formation of non-doped photochromic nanospheres followed by their coating with iron oxide nanoparticles. Magnetic and optical characterisations have demonstrated cooperative effects between both photochromic and magnetic entities as well as structural confinement effects. Azo compounds processed as thin films can generate surface relief gratings under interferential illumination. The resulting photoinduced deformations have been exploited to organise nanoparticles and hybrid nanosystems within the surface relief gratings
Messaoudi, Sabri. "Modélisation des propriétés structurales et physico-chimiques de cations vanadium solvatés et de composés vanadophosphates." Rennes 1, 2004. http://www.theses.fr/2004REN10089.
Fabre, Héloïse. "Contributions des propriétés physico-chimiques de surfaces de titane sur l'adhérence de microorganismes : application aux chambres implantables." Thesis, Le Mans, 2017. http://www.theses.fr/2017LEMA1023/document.
Totally implantable venous-access ports are medical devices used for the administration of chemotherapy drugs and/or parenteral nutrition. Infections can occur and it is indispensable in modern-day medical practice to prevent and reduce the rare infectious complications. In this context, the goal of this work was to study the contribution of the modification of physico-chemical properties of titanium based surfaces on the adherence of microorganisms. Surfaces with different characteristics were produced and the adherence of the bacterium Staphylococcus aureus and the yeast Candida albicans was studied in vitro in static conditions. Model surfaces made of titanium dioxide with roughness from nanometer to micrometer were elaborated using silicon wafers recovered with a thin film of titanium dioxide deposited by plasma vapor deposition. Titanium alloy surfaces (Ti grade 2 and Ti grade 5) were modified by polishing, grit-blasting or wire erosion, to create different surface morphologies. In vitro studies were performed and it was found that the number of adhering microorganisms changed with roughness, but more importantly with the surface morphology of the biomaterials and microorganisms size. Flat titanium dioxide thin films were then functionalized by molecular grafting to modify the hydrophobicity of the surface. Study of plasma protein adsorption, by QCM, allowed to better explain the adherence of bacteria and yeast onto these surfaces. The influence of parenteral nutrition and chemotherapy drugs was also studied in order to better approach the real conditions of totally implantable venous-access ports
Souchard, Jean-Pierre. "Synthèse, propriétés physico-chimiques, et activités pharmacologiques de complexes antitumoraux dérivés du platine (II): relations structure-activité." Toulouse 3, 1990. http://www.theses.fr/1990TOU30128.
Haidon, Blaise. "Synthèse de complexes d’actinides à propriétés physico-chimiques contrôlées pour la fabrication de combustibles oxyde." Thesis, Lille 1, 2017. http://www.theses.fr/2017LIL10086.
Considering the treatment and recycling of future nuclear fuels, the oxalic conversion, which is used at an industrial scale for plutonium (IV) reprocessing, is the synthesis route considered as a reference for the future actinides oxides elaboration. In order to improve this process, based on the actinide oxalate precipitation and the calcination of the precipitate into oxide, a control of the solid properties at the precipitation step is necessary. This is particularly due to the impact of the oxalate morphology at all the stages of the process, up to the calcination at which the oxalate morphology is kept. This study deals with morphology modulations of tetravalent actinides oxalates, thorium (IV) and plutonium (IV), by addition of organic compounds in the precipitation medium. Several impacts of selected “CHON” additives were identified. The molecules, chosen among the actinides complexing and precipitating agents, can act on the crystal structure of the precipitates, the particles morphology, their size and/or their agglomeration. Solid-state analyses combined with the measurements of solubility, nucleation rates, crystal growth rates and agglomeration kernels, allow to shed light on the mechanisms underlying the morphology modulations. This work shows some differences between the behavior of thorium (IV) oxalate and plutonium (IV) oxalate systems. Their origins are discussed in the manuscript. The multidisciplinary methodology developed during this work leads to suggest how to re inforce the additives morphological impacts which can be useful in view of a transposition to other chemical systems, especially other actinides or mixed actinides oxalates
Klotz, Alain. "Contribution à l'astrochimie des molécules organométalliques dans les milieux interstellaires et circumstellaires : approches théoriques et expérimentales." Toulouse 3, 1996. http://www.theses.fr/1996TOU30010.
Clavaguera, Sarrio Carine. "Etude théorique de composés moléculaires d'actinides : propriétés électroniques, vibrationnelles et dynamiques." Toulouse 3, 2003. http://www.theses.fr/2003TOU30049.
Chrayteh, Mhamad. "Caractérisation physico-chimique de composés organiques volatils biogéniques et de leurs hydrates." Thesis, Lille, 2018. http://www.theses.fr/2018LIL1R054.
Our study deal on the physicochemical properties of molecules of atmospheric interest in the gas phase, in particular the microsolvation process, which could be useful to better understand what leads to the formation of secondary organic aerosols. We studied the mechanism of hydration of several oxidation products of monoterpenes, which include myrtenal and perillaldehyde, which are two unsaturated aldehydes of close structures, with the verbenone and the fenchone, which are two ketones. The structures of many conformers (up to 3 molecules of water bound to molecules) have been optimized by quantum chemistry calculations at MP2 / 6-311++G(d,p) and B3LYP-D3BJ / def2-TZVP levels of theory. The hydrates cohesion is done thanks to hydrogen bonds and Van der Waals interactions. We were able to evidence of the existence of many of them by supersonic jet mircowave spectroscopy in the range of frequencies 2 - 20 GHz and determine their experimental structure. For the myrtenal, we recorded and analyzed the pure rotation spectra, as well as those of isotopologists in natural abundance (13C and 18O ). With the support of quantum chemistry calculations, we have determined its molecular structure in the gas phase. Regarding the hydrates of myrtenal, we analyzed the spectra of 2 mono-, 2 di- and a trihydrate, while for perillaldehyde 4 mono- and 2 dihydrates are characterized. With ketones, we analyzed the spectra of 2 mono-, 2 di- and 1 trihydrate of verbenone, while for the microhydration of fenchone, we characterized2 mono-, 2 di- and 3 trihydrates. In order to confirm the structure of the complexes, we used water enriched with oxygen 18, which allowed us through the constants of rotation of the isotopomers to calculate the structure of the detected hydrates by determining the position of the oxygen atoms by calculating their substitution coordinates, as well an effective structure limited to the arrangement of water molecules around the substrate
Mabboux, Florence. "Matériaux implantaires dentaires et adhérence de Streptococcus sanguinis et de Streptococcus constellatus : caractérisation et rôle des propriétés physico-chimiques de surface." Lyon 1, 2004. http://www.theses.fr/2004LYO10236.
In this in vitro study, we have evaluated (i) the interest of 3 different approaches in the characterization of surface properties of implant dental biomaterials (Titanium and Ti-6A1-4V) and of Streptococcus sanguinis and Streptococcus constellatus, with and without saliva, (ii) the number of adherent bacterial cells on these biomaterials , coated with saliva, by analysis of images, (iii) the influence of surface topography and processes of disinfection /sterilisation on surface properties of Titanium, TA6V and on bacterial adherence. Our results show a similar behaviour of titanium and its alloy, the determining role of the method in the physico-chemical characterization of surface properties of bacteria and solids. They confirm the usefulness of determining acid-base interactions and electrostatic properties for a better understanding of streptococcal adhesion on implant dental materials
Azoulay, Ilanith. "Corrosion des aciers à long terme : propriétés physico-chimiques des hydroxysels ferreux." Thesis, La Rochelle, 2013. http://www.theses.fr/2013LAROS410/document.
This study deals with various ferrous hydroxysalts formed in carbonated or sulphated environments. These compounds are known to play an important role during the long term corrosion processes of carbon steel in natural media (soils, seawater). Chukanovite, the Fe(II) hydroxycarbonate with composition Fe2(OH)2CO3, was studied more particularly. Its standard Gibbs free energy of formation could be determined via the detailed study of the equilibrium conditions with Fe(II) hydroxide, performed with aqueous suspensions aged up to 6 months. Potential-pH equilibrium diagrams of iron could then be drawn including chukanovite and highlighting its domain of stability. A comparison with diagrams drawn with siderite FeCO3 revealed that chukanovite was metastable (at 25°C) with respect to siderite. The mechanisms of transformation of chukanovite were also studied for various conditions of oxidation. Hydrogen peroxide was for instance used to accelerate the reaction. The obtained results show that the oxidation of chukanovite leads, at 25°C, to lepidocrocite and/or goethite without the formation of an intermediate Fe(II,III) green rust-like compound. Goethite is favored by an increase of pH (i.e. excess of carbonate). The violent oxidation by hydrogen peroxide leads to a Fe(III) oxycarbonate structurally similar to chukanovite. Finally, two Fe(II) hydroxysulphates could be identified and characterised by X-ray diffraction and infrared spectroscopy. These compounds could not however be obtained alone, but always together, and/or with Fe(OH)2 or maybe a third Fe(II) hydroxysulphate. The study of their oxidation process revealed that all these compounds were first transformed to sulfated green rust
Robira, Maxime. "Propriétés physico-chimiques et comportement différé des matériaux cimentaires sous irradiations gamma." Thesis, Ecole nationale supérieure Mines-Télécom Atlantique Bretagne Pays de la Loire, 2018. http://www.theses.fr/2018IMTA0115/document.
The project of Centre Industriel de stockage Géologique or CIGEO supported by Andra (French Agency for Radioactive Waste Management) will allow storing intermediate level and high-level wastes 500 meters deep inconcrete galleries built in an impermeable argillaceous rock. The main objective of this study is to understand the effects of lower dose rate external gamma irradiations on the physical-chemical and hydro-thermo-mechanical behavior of concrete which could be used in the CIGEO structures and elements. A multiscale and multi-physics experimental protocol has been established during this PhD work. Mortar and cement paste specimens have been irradiated in a gamma irradiator (E = 0.667 MeV,LET = 0.23 keV.μm-1) and subsequently subjected to bending and compressive mechanical stress tests. These irradiations have been performed at the ARRONAX cyclotron facility (Saint-Herblain, France). The variations of compressive and bending strength after irradiation have been measured for different materials (humid, dried and carbonated mortar and cement pastes) showing a high decrease of mechanicals properties. Mechanical variations have been explained by the study of physical-chemical evolution of calcium silicate hydrates (C-S-H), the major phase composing the concrete which can be modified under gamma radiation. Microscopic and macroscopic results were successfully compared to explain the evolution of the cementitious materials under low doserate of gamma radiation
Correia, Sandra. "Etude des propriétés électriques, tribologiques et physico-chimiques de revêtements étamés pour des applications en connectique automobile." Paris 11, 2009. http://www.theses.fr/2009PA112021.
The use of tin as a coating for electrical contact is widespread in electronic systems, especially in the automotive industry. Some field conditions can lead to the degradation of the electrical properties of these contacts and bring failure of systems. This problem of reliability becomes more and more critical. The mechanisms involved in the degradations are numerous, complex and involve a large number of parameters. This thesis aims at increasing the knowledge on the impact of the evolution of tin coating on the appearance of electrical failures of connector type contacts. The collaboration between PEM and LGEP allowed to set up both a rigorous process for the fabrication and control of coating and to set a test procedure applied to representative contacts of connector type. Friction and fretting tests are used to assess the coating behaviour. After structurally, chemically, mechanically and electrically characterizing the tin coating usually used in connector applications, the effects of thermal ageing are described. The influence of the formation of intermetallic phases is shown. Various parameters such as the tin coating thickness, the use of an underlayer and its nature are studied. Then it was attempted to minimize the formation of the intermetallic compounds by acting on their growth kinetics. This was achieved by modifying the diffusion processes of the species in the tin layer, in particular by the use of various underlayers. A process of a tin stripping performed on the thermally aged samples allowed to investigate the mechanical properties of the various intermetallic phases formed. The influence of the chemical composition and of the structure of these compounds is shown. Finally it is shown that the use of a thin (0. 1 μm) cobalt underlayer brings a significant improvement of the coating behaviour: fretting degradation of the contacts is postponed even after a heat treatment
Bouchaala, Nader. "Etude des propriétés structurale et physico-chimique des systèmes Nd-Fe-Co." Thesis, Paris Est, 2017. http://www.theses.fr/2017PESC1043/document.
Intermetallics based on Rare Earths (R) and Metalloids (M) are of interest in the field of fundamental research to understand the nature of magnetic interactions in the complex case where the localized magnetism of the R elements combines with That of the much less localized transition elements. Moreover, exceptional magnet properties make it possible to use them for technological purposes in the field of permanent magnets or magnetic recording. The magnetism group of the CMTR (ICMPE) UMR7182 CNRS-UPEC (France) specializes in the study of the magnetic properties of intermetallics and the correlation of these properties with structural and microstructural properties. The team of intermetallics, of the Laboratory of Materials and Environment Sciences "MESLab" of the University of Sfax (Tunisia), has acquired a great experience in the determination of the diagrams of binary or ternary phases from the study Of the physico-chemical properties of the synthesized compounds. My research project in these two laboratories will involve studying the structural and physicochemical properties of the R-Fe-M systems (R = rare earth, M = transition metal or metalloids) according to the following steps: 1- Establish a ternary diagram between the R-Fe-M elements. 2- Seek new solid solutions. 3- Structural study of the different phases synthesized by different experimental techniques (RX, MEB, X-ray spectroscopy, ...). 4. Study of the magnetic properties of the different phases. 5- Interpretation of the relationships with the nature of the basic elements used
Marty, Philippe. "Coordination organométallique et physico-chimie du milieu interstellaire : Modélisations et expérimentations." Toulouse 3, 1996. http://www.theses.fr/1996TOU30161.
Giry, Clément. "Vers la synthèse verte d'un nouvel organocatalyseur tensioactif biosourcé : détermination de ses propriétés physico-chimiques." Thesis, Toulouse, INPT, 2019. http://www.theses.fr/2019INPT0081.
The development of green chemistry around its twelve principles has changed the way chemists work. The use of water as solvent is evident as it is not toxic, cheap and widely available. However, it is not easy to carry out catalysed organic reactions in water. Indeed, most metalbased catalysts oxidize and become inactive in its presence. Organocatalysis has therefore aroused great interest because of the low toxicity of the employed catalysts as well as their resistance to water and oxidation. In this context, the imidazolidinones developed by D. MacMillan are organocatalysts that can be easily prepared and they can performed, through iminium ion activation, asymmetric catalysis by controlling the stereoselectivity of the reaction. Moreover, to achieve a maximum of organic reactions in water, the use of surfactants is essential. They allow the solubilisation of organic reactions in water through the formation of micelles in the core of which the reaction will occur. In order to use only one molecule, work have been done to graft to an organocatalyst to a long carbon chain, giving it surfactant properties. In this context, our study aims to synthesize a new surfactant organocatalyst on which is grafted an imidazolidinone at the end of the hydrophobic chain. The biosourced synthons of this molecule as well as the reaction conditions were chosen so as to respect as much as possible the principles of green chemistry. As the two first synthetic routes did not lead to the desired molecule, the starting synthons were changed, finally allowing the target molecule to be obtained in 10 steps. More than half of the steps have then been reviewed to improve their green aspect. The main improvement of these steps, and one of this thesis’ innovations, was to reduce the use of compounds toxic for Human and/or environment via, in particular, the replacement of some solvents classified carcinogenic, mutagenic, reprotoxic (CMR) with a new one: 4-methyltetrahydropyran. For each step, the green metrics were calculated to justify if it was an improvement. Finally, once the targeted molecule obtained, its solubility in water was studied. Its surfactant character was then characterized in order to verify its activity on the surface tension at the water-air interface. The determination of the size of the aggregates formed in water as well as the molecular modeling completed the state of knowledge of the type of self-organized structures realized by this new molecule
Léger, Valentin. "Propriétés physico-chimiques des défauts dans les alliages II-VI pour la détection infrarouge." Electronic Thesis or Diss., Sorbonne université, 2023. http://www.theses.fr/2023SORUS214.
Improving II-VI material quality is an essential step to maintain high electro-optical performances at higher operating temperature of cooled infrared detectors (HOT technologies). Indeed, image quality and stability are challenged by the electrical activity (low-frequency noises) induced by some crystal defects. The aim of this thesis work is to characterize several crystal qualities of the epitaxial Hg1-xCdxTe as well as its Cd1-xZnxTe substrate by spectroscopic techniques, and to establish a comparative review of the physico-chemical fingerprints of point defects. For this purpose, defect populations were investigated in both compounds by positron annihilation spectroscopy (PAS). The electron antiparticle is particularly sensitive to open-volume defects, intrinsically present in high concentrations in the considered alloys. Vacancy concentration profiles in the near-surface region can then be obtained with a slow positron beam. The substrate study was extended with spectrally resolved cathodoluminescence (CL) measurements. This technique is especially powerful at low temperature where defects involved in radiative mechanisms have been identified. CL also allows to map luminescence properties at the sub-micrometer scale
Aljawish, Abdulhadi. "Fonctionnalisation enzymatique de chitosane par des composés phénoliques : évaluation des propriétés biologiques et physico-chimiques de ces nouveaux biopolymères." Thesis, Université de Lorraine, 2013. http://www.theses.fr/2013LORR0089/document.
Oxidation of ferulic acid and its ester (ethyl ferulate) by Myceliophtora thermophila laccase has been studied in aqueous medium under mild experimental conditions (30°C and pH 7.5) as a green process to synthesize natural neo-molecules. Enzymatic oxidation led to colored and colorless intermediaries for ferulic acid and ethyl ferulate, respectively. Additionally, ethyl ferulate was oxidized faster than ferulic acid. This procedure has led to dimeric major products with MM = 443 g/mol and MM = 386 g/mol for ethyl ferulate and ferulic acid, respectively. New synthesized molecules demonstrated important antioxidants properties with weak antibacterial and cytotoxic properties. With insoluble chitosan particles in the reaction medium, laccase was protected from inhibition due to oxidation products and the polymerization degree of these products was checked. In addition, the oxidation products reacted with the free NH2 groups forming covalent bonds of Schiff base type (C=N) at C-2 region. The majority of the oxidation products grafted onto chitosan was of dimeric form. This procedure led to colored and colorless chitosans by ferulic acid and ethyl ferulate, respectively, with new properties due to grafting of phenolic compounds. These chitosan derivatives presented interesting functional properties such as antioxidant, physico-chemical (thermal stability) and biological (cell adhesion) as well as the preservation of antibacterial properties of native chitosan
Méjean, Pierre. "Etude des propriétés physico-chimiques de fluorosilanes. Application à l'élaboration de membranes utilisées en diffusion gazeuse." Montpellier 2, 1997. http://www.theses.fr/1997MON20153.
Evariste, Sloane. "Systèmes π-conjugués et assemblages supramoléculaires organophosphorés : synthèse et propriétés physico-chimiques." Thesis, Rennes 1, 2016. http://www.theses.fr/2016REN1S058/document.
This manuscript describes the synthesis and characterization of new molecular systems based on phosphorus atom: we developed and studied π-conjugated systems based on phosphole and secondly supramolecular assemblies with phosphine ligand have been studied. Firstly, an introduction to the phosphole chemistry (history, synthesis methods, integration into π-conjugated systems) is presented. The first chapter describes the synthesis and physico-chemical study of phospholes derivatives having an extended π-system for the development of orange-red emitters in organic light-emitting diodes (OLEDs). Different molecular engineering involving the triple bond leads to modifications of the optical properties of the synthesized compounds by red-shifting their absorption and/or emission maxima. Chapter II describes the synthesis and the physical properties of complexes using phosphole based π-systems as linkers between two metal centers. New Fe (II), Pt (II) and Au (I) complexes have been developed and the electronic communication between the two metals is studied. The second part of the thesis work starts with a review on the emissive Cu(I) complexes. In Chapter III, are presented the syntheses, the structural and optical studies of new solid-state emissive supramolecular assemblies synthesized from pre-assembled Cu(I) molecular clips and stabilized by phosphine ligands (dppm or dpmp) with cyano ligands as linkers. Then in the final chapter new Cu(I) complexes are synthesized by using organic ligands with terminal nitrile functions as linkers. The solid-state luminescence properties of these new Cu(I) derivatives are studied according to their external environment and thermochromism, vapochromism and mechanochromism phenomena have been demonstrated for some of them
Adam, Laure. "Synthèse, caractérisations structurales et physico-chimiques de nouveaux phosphates d'éléments de transition." Caen, 2009. http://www.theses.fr/2009CAEN2057.
This thesis deals with the study of transition element phosphates, whose mixed frameworks contain cavities able to host cations. The great structural wealth in this family of compounds opens the way to numerous properties. We have chosen to study A-M-P-O(-H) systems in which A is a monovalent cation and M is a transition element (mixed-valent if possible) or post transition element, in order to obtain new materials for catalytic applications. In this context, the study of the A-M-P-O(-H) systems, with A = NH4, Li, Na, K, Rb, Cs and M = Fe, Mn and In has been undertaken. The other aim of this work was a better understanding of the influence of synthesis experimental conditions on the nature of the obtained phases. In spite of the difficulty to synthesize new materials in the considered systems, eleven new phases have been isolated and three of them exhibit original framework. Structural determinations have been performed by single crystal X-ray diffraction combined with powder X-ray diffraction and EDX analysis. The study of catalytic properties for DeNOx reaction via the NH3-SCR have been carried out by “in situ” and “operando” spectroscopy and mass spectroscopy for one iron phosphate. Magnetic properties of four compounds, which are reported in this manuscript, are discussed
Bololoi, Ana-Maria Cristina. "Nouveaux amphiphiles catanioniques analogues du galactosylcéramide : corrélation structure, propriétés physico-chimiques et activité anti-VIH." Toulouse 3, 2008. http://thesesups.ups-tlse.fr/232/.
This study was focused on the development of new catanionic surfactant analogues of GalCer (an alternative cellular receptor of the HIV) for the anti-HIV therapy. The first part of the study was focused on new dendritic catanionic associations having a reduced toxicity and which were intended to be used as multisite chimeras for the HIV. The biological tests, the physico-chemical properties and the interaction of these compounds with a membrane model allowed us to establish a relationship between the structure, the hydrophoby, the conformation and the biological activity of these products. The aim of the second part of the study was to build up an anti-HIV drug delivery system. In this purpose new hybrid (fluorinated/hydrogenated) catanionic analogues of GalCer were investigated. Among these compounds which are able to spontaneously form vesicles in water having a good stability in time, we identified a very promising candidate for the delivery of anti-HIV drugs to the infected cells
Jeannot, Cécile. "Synthèse et étude des propriétés structurales, magnétiques et chimiques de ferrates (IV), (V) et (VI) alcalins." Nancy 1, 2000. http://www.theses.fr/2000NAN10132.
Synthesis, magnetic and chemical properties of alkaline ferrate (IV), (V) and (VI) have been investigated. The first part of this report is devoted to the study of the K-Fe -O system. After a bibliographical review of potassium oxides, the syntheses carried out by. , solid-state reaction between KO2 and an iron oxide have showed that it is possible to synthesise K2FeO4 at 350°C under atmospheric pressure of oxygen, or at 450°C in a sealed "Pyrex" tube. Ferrate (V) was only detected in some of mixtures, the oxidation step (IV) was never found. The study of the Na-Fe -O system lead to evidence the existence of sodium ferrate (IV) Na4FeO4. This phase crystallises in the triclinic system and belong to the Na4MO4 series (M = transition element). In this compound, iron is in a tetrahedral site. Na4FeO4 is aritiferromagnetic below 16 K. The study of the magnetic structure shows that the exchange interactions may form via Fe-O-Na-O-Fe superexchange ways. Na4FeO4 is the first example of material which stabilises Fe (IV) in a tetrahedral site. With our experimental conditions, it was not possible to stabilise the oxidation step (VI), whereas a ferrate (V) could be detected while operating in presence of oxygen generated in-situ in the sealed Pyrex tube or in presence of hydroxide. The study of the Na-K-Fe-O system evidenced the existence of the oxidation step (V) in a compound with the K2NaFeO4 formula. Isotypic with K2NaMnO4, iron (V) is tetrahedrally co-ordinated. Paramagnetic until 6 K, the Mössbauer parameters ofthis Fe (V) high spin have been specified for the first time. The optimization of the synthesis of ferrate (VI) by electrochemical way is also described. Ferrate (IV) and (V) di sproportionate to give Fe (VI) and Fe (III). The last part of this work is devoted to the chemical propel1ies of ferrate (VI) which has potential industrial applications in the field of energy and environment
Saravia, Alvaro. "Synthèse des combustibles carbures à partir de précurseurs nanostructurés : impact sur la carboréduction et les propriétés physico-chimiques." Thesis, Montpellier, Ecole nationale supérieure de chimie, 2015. http://www.theses.fr/2015ENCM0009.
The synthetic route conventionally used to manufacture carbides fuels involves carboreduction of a mixture of AnO2 powders and graphite at high temperature (1600 °C) and under a low vacuum. These conditions are disadvantageous for the synthesis of mixed carbides (U,Pu)C due to volatilization of plutonium. This is why one of the main goals of this work was to reduce the temperature of carboreduction. Our work was mainly carried on the lowering of the temperature of carboreduction of uranium oxide. This result was achieved by increasing the reaction surface between the carbon and uranium oxide. To do this colloidal suspensions of uranium oxide nanoparticles were prepared and stabilized with cellulose ethers. Cellulose ethers serve both as a stabilizer for the uranium oxide nanoparticles, but also as a carbon source for the carboreduction. These precursors have shown to be more efficient for the carboreduction compared to the standard precursors: a reduction of 300 °C on the carboreduction temperature was obtained under low vacuum. The impact of this type of precursors on the carboreduction and physicochemical properties and the structural and microstructural characterization of obtained carbide were performed
Guan, Shian. "Étude de la synthèse de dioxyde de vanadium : propriétés physico-chimiques, dopages élémentaire et applications sous forme de films." Thesis, Bordeaux, 2019. http://www.theses.fr/2019BORD0443.
VO2 oxide is a promising material for energy-saving smart windows due to its reversible metal-to-insulator transition at 68℃, accompanied by large optical changes from a low temperature transparent state to a more blocking state at high temperature in the near-infrared region. From a crystallographic point of view, the VO2 transition occurs between two crystal phases: monoclinic (M) and rutile (R) phases.The limiting factors for a commercial use are the high transition temperature, unpopular yellow color (film) and poor thermal and chemical stability. Most importantly, there is still lack of a reproducible and low-cost method for VO2 particles synthesis.Two synthesis methods for VO2 powder are proposed. Firstly, VO2 (M) powders with tuned crystallinity were prepared through a two-step thermal treatment: a fast VEG decomposition in air leads to the formation of poor crystal VO2, followed by a post-annealing treatment at higher temperatures in vacuum for a full-crystallization. The second method, named as carbo-thermal reduction method, is based on the reducing role of carbon. Herein soot is chosen for a direct reduction of homemade V2O5 nano-powder. The comparison of sealed or dynamic vacuum systems allows further understanding of the reductive mechanism. The obtained VO2 particles size varied from 5.3 um to 415 nm by adjusting the annealing temperature and time. In addition, Al3+, Ti4+ and Nb5+ metal ions can be doped into VO2, successfully. Nb5+ shows the most efficient effect on decreasing of the transition temperature down to Tc= 25°C.The doping effects of Nb on VO2 are fully investigated on several aspects, including the morphology, crystal distortion, thermal stability, heat capacity and resistivity. Finally, a deep investigation of the magnetic properties with respect to the impact of the doping concentration and the particle size is proposed.The shaping step into thin films, is performance using a dip coating process from VO2 suspensions. This step is investigated to tackle down the trade-off relationship between luminous transmittance (Tlum) and solar-energy modulation ability (ΔTsol) in VO2-based thin films. Zero dimensional island structured VO2 films are fabricated by taking advantage of the reductive strategy using carbon as developed in previous part. PVP is used as a surface stabilizer and reducing agent. To tune the functional materials VO2’s surface coverage on substrate, three elaboration parameters were changed: (i) the suspension concentration; (ii) the V2O5@PVP film layer thickness; (iii) the number of VO2 layers through repeating the spin-coating/annealing loop.Finally, the driving force of the phase transition of VO2 type oxides is still unclear: as far as distortion is concerned, some authors propose to explain this transition a distortional induced structural origin (Peierls model), other state that the transition proceeds by a complex electron-electron correlation (Mott model). We discuss our point of view on this metal-insulator transition of VO2 oxides. In the limits of a simple geometrical approach, we describe here with a new approach, the main driving forces involved in the MIT transition of VO2 oxides. This approach, based on the binding valence model, a well-established model, has allowed us to show that the phase transition is certainly consistent with a maximization of the lattice energy due to a maximization of the unit-cell volume of the VO2 oxides, in other words, the most stable allotropic form is that presenting for a given temperature the largest unit-cell volume
Lacombe, Guillaume. "Rôle des paramètres d'élaboration sur les propriétés physico-chimiques de matériaux composites élaborés par métallurgie des poudres : études théoriques et expérimentales." Phd thesis, Université Sciences et Technologies - Bordeaux I, 2011. http://tel.archives-ouvertes.fr/tel-00681508.
Speyer, Lucie. "Élaboration de mousses de graphène par voie solvothermale et modification de leurs propriétés physico-chimiques." Thesis, Université de Lorraine, 2016. http://www.theses.fr/2016LORR0120/document.
Graphene-based materials have attracted a great interest these last years, due to their outstanding properties. In particular, graphene foams offer a part of the properties of graphene, combined with a high surface area: they show great potentiality in some application domains such as energy. This thesis work is focused on the elaboration of graphene foams by a solvothermal-based process, an original method involving a solvothermal reaction between an alcohol and sodium, followed by a thermal treatment. The study of the compounds produced by the solvothermal reaction and the pyrolysis under a nitrogen flow was lead through multi-scale and complementary characterization techniques: mechanisms of formation of the solvothermal compound and graphenic foams have been proposed. The optimal conditions of pyrolysis were also determined, and provide the obtaining of graphene foams with a high structural quality and a large specific surface area. Furthermore, some types of post-elaboration treatments were carried out: notably, a vacuum annealing significantly improves the structural quality and the purity of the samples. Lastly, the modification of the physico-chemical properties of the foams through the chemistry of carbon materials intercalation has been studied. Graphene films were prepared from the intercalated foams and their electrical properties were evaluated
Jeanneau, Justin. "Synthèse et propriétés physiques sous haute pression de composés à base de Cr4+." Thesis, Université Grenoble Alpes (ComUE), 2016. http://www.theses.fr/2016GREAY088.
After 25 years of research on the superconducting cuprates, the discovery of high Tc superconductivity in related iron based pnictides in 2008[1] has stimulated the search of new superconductors. In particular antiferromagnet (AFM) with high Néel temperature, moderate magnetic moments and with crystallographic 2D layers could be adequate parent phases for new unconventional superconductors. In particular, other systems with 3d transition elements are very interesting systems for potential new high Tc superconductors.In this context we have reinvestigated the physical properties of n=1, 2,3 and + members of the Srn+1CrnO3n+1Ruddlesden Popper (RP) series. We have successfully synthesized at HP-HT Sr2CrO4 (n=1), Sr3Cr2O7(n=2), Sr4Cr3O10 (n=3) and SrCrO3 (n=infinite). We present some results of several studies performed on these phases such as neutron powder diffraction, Synchrotron X-ray diffraction under high pressure and low temperature, electrical transport properties under high pressure. Even if no superconductivity was observed, interesting properties had been discovered such as an unusual “anti-Jahn-Teller” in Sr2CrO4 at low temperature or an orbital ordering in Sr3Cr2O7.To explore new Cr-based systems where superconductivity could potentially be induced by changing Cr-Cr interactions in the Sr2CrO4 and Sr3Cr2O7RP phases, new chromates have been synthesized under HP-HT by substituting Sr2+ with other alkaline earth elements in order to “play” with the cation size effect. For the n=1 RP Ca2CrO4 phase, substitution with Ca2+ as a replacing element lead to a weakening of both the insulating behavior and AFM ordering. Synthesis to form the n=2 RP Ca-based lead to the formation of the unexpected and new n=3 phase Ca4Cr2O10.Ba2+ as a replacing element broke the RP structure configuration and led to a new phase, whose crystal structure was solved using electron diffraction tomography.In 2014, superconductivity has been discovered in CrAs (Tc=2.2K at P=0.8GPa), the first superconducting Cr-based system. In this context, we have look for other AFM Cr-based system with relatively high Néel temperature and moderate Cr magnetic moment. In consequence, we investigated another system, the narrow-gap semiconductor CrSb2. We find a metal-insulating transition from transport measurement at 10 GPa for both polycrystalline and single crystals samples we synthesized. At this pressure, we also observed a phase transition on synchrotron XRD under pressure. Finally, pressure dependence of the AFM ordering had been established by NPD under high pressure
Auriol, Mélodie. "Influence des interactions physico-chimiques entre particules et composés organiques sur la stabilité de mousses minérales." Thesis, Bordeaux, 2016. http://www.theses.fr/2016BORD0241/document.
Cement-based mineral foams are solid porous materials and presentvery interesting insulating properties. Such materials are used in the constructionsector in order to reduce the energy consumption of houses. However, theproduction of these materials can be difficult because of the kinetic competitionbetween foam stability and cement setting. Cement-based mineral foams areextremely complex materials because of the number of components and all theirinteractions. The objective of our study is to get insight into the interactions betweenmineral and organic compounds and to understand their role in the stabilizingmechanisms. Our strategy was to study a model system, sufficiently close the realone to be representative, and sufficiently simple to identify the contribution of thedifferent components. We used as a foaming agent a surfactant exhibiting acharacteristic peak in UV-visible spectroscopy in order to determine its function andposition in the complex system. We first worked on unfoamed slurries, then westudied thin liquid films and the foamed materials
Bescond, Alexandre. "Contribution à la métrologie des nanoparticules de suie et à la caractérisation des particules produites par un générateur de référence." Rouen, 2015. http://www.theses.fr/2015ROUES063.
In the context of the civil aviation impact on the environment, the French aerospace and environment thematic network (called RTAE) of the French council for civil aeronautics research (CORAC) launched a study on contrails formation. The environmental impact of the induced cirrus generated by air traffic in altitude was also analyzed. The project in which this thesis is carried out (MERMOSE project, financed by the French general council of civil aviation) aims to characterize the particles emitted by an aeronautic engine and to study the soot reactivity with water. First of all, the work presented in this manuscript contributes to the improvement of the metrology of aerosol produced by combustion (soot). Furthermore, tools are designed and implemented to accurately characterize the nanoparticles produced by a reference aerosol combustion generator (miniCAST 5201c) and by an aircraft engine. Significant metrology means have been used to characterize the morphological, physico-chemical and optical properties of soot nanoparticles. Besides the use of standard commercial devices (SMPS sizer, mass concentration TEOM, Transmission Electronic Microscopy TEM …), optical techniques have also been used (depolarization of light, extinction spectra). The coupling of those techniques leads, for example, to the determination of the effective density or to the determination of optical properties. The exploitation of the obtained results has been carried out by using theories, modelling or methods that have been proposed (modelling of the effective density, automatized processing of TEM images) or improved (theory of light interaction with aggregates RDG-FA with the taking into account of internal multiple scattering). Accordingly, these new findings intend to improve the accuracy of the previously developed techniques. For example, the impact of accounting for a realistic morphology of aggregates (overlapping and necking between primary particles) has been studied. The use of the aforementioned techniques or methods permitted to reach key parameters such as the size distribution of primary particles, the fractal dimension of aggregates, the bulk density of primary spheres and their optical properties, opening the way to an optical speciation of soot nanoparticles by their organic compounds content and microstructure (amorphous or graphitic). The miniCAST generator allows to produce soot nanoparticles with a great stability and repeatability with various morphological and physico-chemical (and by the way optical) properties. This generator can be used as a surrogate of soot generated by different sources
Arvisenet, Gaëlle. "Influence des interactions physico-chimiques entre amidons et composés d'arôme sur la libération des arômes et les propriétés rhéologiques dans des matrices aqueuses complexes." Dijon, 2001. http://www.theses.fr/2001DIJOS058.
Ndiaye, Augustin. "Recherche de corrélations entre capacité lubrifiante et propriétés physico-chimiques d'un lubrifiant de phase solide pour compression uniaxiale de matériaux particulaires pour applications pharmaceutiques : cas du stéarate de magnésium." Dijon, 2003. http://www.theses.fr/2003DIJOS013.
Agach, Mickaël. "Synthèse et étude des propriétés structurales, physico-chimiques et fonctionnelles d'oligoesters tensioactifs branchés à base d'acide succinique bio-sourcé et de glycérol." Thesis, Lille 1, 2012. http://www.theses.fr/2012LIL10082/document.
The synthesis and the study of new crop-sourced and branched amphiphilic oligoesters based on bio-sourced succinic acid, glycerol, fatty acids and other crop-sourced building blocks have considered for surfactive applications in various fields as substitutes for petrochemicals. The implemented strategy is part of an eco-design approach to obtain acceptable organoleptic, physico-chemical and functional properties comparable to those of benchmarks. At first, the impact of succinylation on the physico-chemical and functional properties of non-ionic surfactants derived from ethoxylated fatty alcohols, glycerol monolaurate and alkyl polyxylosides has been studied. In a second step, non-toxic and biodegradable poly(glycerol-succinic acid) oligomers, PGSs, were synthesized without solvent nor catalyst and characterized with the intention of developing new bio-sourced polar heads of surfactants. Mathematical models have been developed so as to extract the widest range of structural information such as the number-average degree of polymerization, DPn from the quantitative 13C NMR data. In the third phase, acyl poly(glycerol-succinic acid) oligomers or acyl PGSs were synthesized and studied. It has been shown that lauroyl derivatives form abundant and stable foams, exhibit a wide range of wetting powers and display excellent properties of micellar solubilization. Finally, to improve the physico-chemical and functional properties of the lauroyl PGSs obtained by catalyzed synthesis by increasing the homogeneity of the reaction mixtures, comonomers were used as copolymerizable solvents. Within the context of a tightening legislation, this type of bio-sourced macromolecules constitutes a promising platform paving the way for further chemical modifications and various grafting to target other potential applications
Iroulart, Marie-Gabrielle. "Contribution à l'étude des gels et des xérogels de phosphate de thorium." Paris 11, 1989. http://www.theses.fr/1989PA112286.
Fischer, Arnaud. "Synthèse de nouveaux copolymères amphiphiles cationiques a blocs par voie radicalaire contrôlée et examen de leurs propriétés physico-chimiques en solution aqueuse." Vandoeuvre-les-Nancy, INPL, 2000. http://www.theses.fr/2000INPL069N.
Brunot-Gohin, Céline. "Optimisation des états de surface du titane et des alliages en nickel-titane par des films multicouches de polyélectrolytes." Phd thesis, Université Claude Bernard - Lyon I, 2009. http://tel.archives-ouvertes.fr/tel-00771411.
Dziadosz, Laure. "Synthèse de nouveaux copolymères amphiphiles cationiques à blocs, par voie radicalaire à l'aide d'iniferters : étude de leurs propriétés physico-chimiques en milieu aqueux." Vandoeuvre-les-Nancy, INPL, 1997. http://docnum.univ-lorraine.fr/public/INPL_T_1997_DZIADOSZ_L.pdf.
Piquemal, Fabrice. "Réactivité du méthanol et du dioxyde de carbone avec des oxydes et des complexes de l'étain (IV)." Toulouse 3, 1993. http://www.theses.fr/1993TOU30074.
Cabannes-Boue, Jérôme Benjamin. "Exploitation en ingénierie macromoléculaire de la photolyse des composés de type thiocarbonylthio." Thesis, Mulhouse, 2017. http://www.theses.fr/2017MULH1239.
This thesis aimed at studying the photochemical reactivity of the thiocarbonylthio compounds in polymerization reactions. This reactivity can be exploited in two ways depending on the light source used: either a partial and reversible photolysis under visible or a complete photolysis under UV irradiation.In the first case, this reactivity has been exploited to develop a photo-mediated RAFT mechanism. A new RAFT agent with a strongly absorbing N-carbazole chromophore as the Z group was synthesized in order to enlarge the domain of usable wavelengths. An excellent control of the polymerization of acrylates was observed as well as the temporal control of the reaction by switching on/off the light source. A kinetic modelling describing the effect of light intensity was then proposed. Thanks to this model, the conditions required to optimize the control and extend it to others monomers have been identified.In the second case, the thiocarbonylthio compounds reactivity was greatly enhanced by introducing a N-carbazole chromophore either as a terminal monomer unit or as the Z group of the RAFT agent. The synthesized RAFT polymers were then used as efficient and versatile macrophotoinitiators, being able to initiate both free radical and radical promoted cationic polymerizations under UV irradiation. In addition, macrophotoinitiators with functional side groups were also synthesized, which can improve the properties of photopolymer coatings.These studies have opened new perspectives in macromolecular engineering, such as for instance the synthesis of original bloc copolymers by combining two photo-induced mechanisms