Teses / dissertações sobre o tema "Chimie colloïdale"
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Masion, Armand. "Chimie moléculaire et colloïdale des complexes organiques de l'aluminium III partiellement hydrolysés". Vandoeuvre-les-Nancy, INPL, 1993. http://www.theses.fr/1993INPL028N.
Texto completo da fonteDepagne, Christophe. "Synthèse de micro-biocapteurs optiques par déstabilisation colloïdale en micelles inverses". Paris 6, 2009. http://www.theses.fr/2009PA066159.
Texto completo da fonteBogicevic, Alexandra. "Synthèse colloïdale de structures hybrides or/quantum dots". Electronic Thesis or Diss., Université Paris sciences et lettres, 2021. http://www.theses.fr/2021UPSLS092.
Texto completo da fonteColloidal semiconductor nanocrystals, also known as quantum dots (QDs), have exceptional optical properties, such as high absorption cross section and quantum yield. Their emission spectra can be tuned by changing their size, their shape or composition. Recently, our group reported the plasmonic coupling of unique QD emitters embedded in silica coated with a gold nanoshell with a Purcell factor of 6. The resulting emitters showed enhanced photostability and reduced blinking rates.In this thesis, we explore synthesis and optical properties of similar objects containing not one but hundreds of QDs in their core (superparticles).We first synthesize CdSe/CdS/ZnS core/multishell QDs and assemble them into aggregates of controlled sizes by emulsion/evaporation. The aggregates are then coated with a silica shell (Stöber process) and with a gold nanoshell using a deposition process.The optical properties of QD aggregates with and without gold shells are addressed. These objects exhibit high quantum efficiency, as well as stable and Poissonian emission at room temperature. In addition, we demonstrate a Förster-type resonance energy transfer (FRET) between neighboring QDs inside the aggregates. We also prove that polyvinylpyrrolidone (PVP) can be used to regulate both the reduction rate of gold and the morphology of the gold nanoshell.The second objective is to transpose this synthesis onto 2D semiconductor nanocrystals called nanoplatelets (NPLs) which exhibit particular emission polarization properties thanks to their anisotropic shape. To preserve this anisotropy throughout the synthesis process of the gold nanoshells, a supplementary extension step has to be conducted on these NPLs
Cerveaux, Augustin. ""From an art to a science" : chimie colloïdale, pigments et recherche fondamentale chez Du Pont de Nemours, 1900-1945". Strasbourg, 2010. http://www.theses.fr/2010STRA6154.
Texto completo da fonteThis dissertation deals with the emergence and growth of colloid chemistry in the early twentieth century, focusing particularly on the history of the colloid group set up at Du Pont, a major American chemical company, during the interwar period. It explores the relationship between the scientific issues raised by “colloidal” substances, and the technical, industrial and economic dimensions of the associated materials. The concept of “ontological shift of materials”, recently forged by two historians of chemistry, is appropriated as an interpretative framework to account for these evolutions in colloid science and technology. The paint and varnish industry, whose materials were then largely considered as colloidal, is taken as a major case study to analyze these relationships and evolutions, and its history is explored since the beginning of the century. The group was propelled by the quantification of the microstructure of these materials, in order to better explain and master their practical properties. The dissertation details why and how this new understanding of the properties of many substances on the basis of their microscopic components became, from the interwar onwards, embedded in the “rationalization” of the properties of materials, the processes to produce them, as well as the associated patents. This rationalization of products and processes is concomitant to the emergence of mass consumption – and the new emphasis on the “consumer” figure within companies – of industrially produced goods, particularly those of the paint and varnish industry
Chabert, Anne-Marie. "Étude de la clarification des fines de dissolution des combustibles nucléaires irradiés". Châtenay-Malabry, Ecole centrale de Paris, 1991. http://www.theses.fr/1991ECAP0723.
Texto completo da fonteRose-Hélène, Maureen. "Aspects thermodynamiques et cinétiques de la complexation de cations métalliques (Cu²+ et Ni²+) par la 5-phénylazo-8-hydroxyquinoline (5Ph8HQ) et le cyclame greffés sur des nanoparticules de silice en suspension colloïdale". Thesis, Nancy 1, 2011. http://www.theses.fr/2011NAN10060/document.
Texto completo da fonteWe considered both the thermodynamic and kinetic aspects of metal ions (Cu2+ and Ni2+) complexation by 5-phenylazo-8-hydroxyquinoline (5Ph8HQ) and cyclam grafted onto silica nanoparticles in colloidal dispersion. Fumed silicas with specific areas of respectively 200 and 390 m2/g were selected to get stable colloidal suspensions. We demonstrated the ability of these colloids to extract trace elements (at micromolar level). We used the ultrafiltration process to separate the dispersed silica phase from the aqueous phase. We also showed interest of our solid dispersed phases instead of a pseudo micellar one. We described complexation kinetics by stopped flow technique for the fastest reactions. The influence of metal cation concentration, counter-ion nature (acetate or chloride), ionic strength and pH on observed rate constant has been investigated. To describe the Ni2+ kinetics with grafted 5Ph8HQ, we took into account the spectrophotometric properties of the complex on silica nanoparticles. This is an original behaviour of 5Ph8HQ on silica since the optical densities of solutions containing 5Ph8HQ solubilised in micelles or cyclam grafted onto silica follow the Beer-Lambert's law. The study of grafted cyclam whether the kinetics or equilibrium is complicated due to the release of the latter in solution
Pesesse, Antoine. "Synthèse de nanoparticules contenant des métaux pour la catalyse assistée par des bases de Lewis en suspension colloïdale". Electronic Thesis or Diss., Sorbonne université, 2021. https://accesdistant.sorbonne-universite.fr/login?url=https://theses-intra.sorbonne-universite.fr/2021SORUS530.pdf.
Texto completo da fonteIn this work, we synthesised copper based and gold nanoparticles to produce a catalytic activity in combination with a molecular Lewis base in colloidal suspension. A bibliographic research, showed the potential of using a sterically hindered tertiary phosphine to obtain a “Frustrated Lewis Pair” type of interaction with the nanoparticle surface (Chapter 1). Previous works unveiled that the formation of an oxide shell could explain the lack of stability of copper nanoparticles toward tertiary phosphine (Chapter 2). To prevent its formation, the nanoparticles were washed under inert atmosphere. The oxide was still detected and the nanoparticles were subject to leaching. Mechanistic study suggest that water could be responsible for oxidation formation (Chapitre 3). A new procedure to sulfurize copper nanoparticles was developed but the nanoparticles obtained were unstable toward tertiary phosphines (Chapter 4). A new synthesis of N-heterocyclic carbene stabilized copper nanoparticles using more accessible and oxygen free precursors was proposed and delivered nanoparticles that are both oxide free and stabilized by very strong ligands (Chapter 5). The synthesis mechanism was studied in details. The influence of phosphine on the catalytic activity of gold for reduction and hydrogenation in colloidal suspension were assessed (Chapter 6)
Bitar, Ahmad. "Élaboration de la silice magnétique colloïdale pour application en biologie moléculaire : extraction des acides nucléiques". Phd thesis, Université Claude Bernard - Lyon I, 2013. http://tel.archives-ouvertes.fr/tel-01069003.
Texto completo da fonteEyssautier, Joëlle. "Caractérisation et Modélisation des Asphaltènes en Conditions Réactionnelles d'Hydrotraitement". Palaiseau, Ecole polytechnique, 2012. http://pastel.archives-ouvertes.fr/docs/00/66/69/75/PDF/ThA_se_Joelle_Eyssautier_2012_pour_impression.pdf.
Texto completo da fonteDue to a high energy demand, the petroleum industry has to focus on low quality products such as heavy oils and distillation residua, to be transformed into valuable fractions. These products show difficulties to be converted during hydrotreating processes because of their asphaltene content, which are heavy molecules with peculiar aggregation properties. Small angle scattering techniques (X rays, neutrons and light) were used to characterize the system on a wide length scale (1 nm - 1 μm). Asphaltenes in model solvents were first investigated to refine the description of nanoaggregates made of core/shell discs, organized at a larger length scale into polydisperse fractal clusters. This colloidal approach was then adapted to study the asphaltenes in processing conditions. A nanofiltration process has been performed, and the structural study of the fractions made evidence that the system is a colloidal suspension of particles. The behavior through temperature elevation depends on the length scale of interest: while clusters are sensitive to temperature, nanoaggregates persist at 300°C. The hierarchical aggregation scheme enables predicting viscosity behaviors through temperature and concentration variations. These findings on structural organization and characteristic particle sizes near processing temperatures improve the knowledge required for heavy oil transport, hydroconversion process and catalyst design
Lartiges, Bruno. "Déstabilisation d'une suspension de silice colloïdale par un sel d'aluminium : relations entre les phénomènes de surface, la structure et la granulométrie des flocs". Vandoeuvre-les-Nancy, INPL, 1994. http://docnum.univ-lorraine.fr/public/INPL_T_1994_LARTIGES_B_S.pdf.
Texto completo da fontePedetti, Silvia. "Synthesis and optical properties of II-VI colloidal two-dimensional nanocrystals : homo- and hetero-structures". Electronic Thesis or Diss., Paris 6, 2015. http://www.theses.fr/2015PA066755.
Texto completo da fonteThis thesis project is based on the development of a novel class of colloidal two-dimensional nanocrystals, i.e. nanoplatelets (NPLs), composed of cadmium chalcogenides. These nanocrystals, in analogy to quantum wells, are characterized by an exciton confinement along one direction, i.e. the thickness, which can be controlled at atomic level. Nanoplatelets possess unique optical features as an excellent spectral resolution and good quantum yields. As consequence these nanocrystals are potential candidates for the fabrication of optoelectronic devices such as electroluminescent diodes or photo-detectors. However, for this aim it is necessary to enlarge the range of the absorption and emission wavelengths and to increase their quantum yield. For this reason, we investigated the colloidal synthesis of II-VI homo- and hetero-nanoplatelets which have been characterized by UV-Vis and photoluminescence spectroscopy, by X-ray diffraction and by electronic microscopy. First, we optimized the synthesis of CdTe NPLs using colloidal synthesis based on precursors injection at high temperatures. Then, we focused on more complexes hetero-structures. For example, through lateral extension reactions we obtained CdSe/CdTe core/crown NPLs which possess a type-II electronic structure. Successively, we studied the synthesis of core/shell NPLs by the growth of a second semiconductor layer along the thickness of NPLs cores. Depending on the core and shell chemical composition we could engineer the band gap of the nanoplatelets between type-I, quasi type-II and type-II electronic structures
Tran, Công Tâm. "Simulations de fluides complexes à l'échelle mésoscopique sur GPU". Thesis, Limoges, 2018. http://www.theses.fr/2018LIMO0024/document.
Texto completo da fonteColloïdal suspensions have been studied by means of numerical simulation, using two physical models : Brownian dynamics and Stochastic Rotation Dynamics - Molecular Dynamics. These studies consist in parallizing colloïdal simulations from previous studies on GPU, and find some new optimisations for these specific simulations. An improvement of the neigborhood search has been implemented in all our BD type simulations. A SRD-MD with force coupling have been implemented for the first time in the literature, using a new decomposition scheme, which improves significantly its performances. Then, theses simulations have been adapted to study more complex colloidal suspensions : an interfacial heteroaggregation of colloidal suspensions, a heteroaggregation between two types of particles with a large size ratio, and outside this context, a nanoalloy simulation. Finally, the SRD model has been adapted to realistic fluid animtion from computer science context. Theses adaptations require to add to SRD model, the notion of compressibility and surface tension. First results have been released, like a pouring water into a glass simulation
Brastel, Alexis. "Architectures (co)polymères à liens covalents dynamiques". Electronic Thesis or Diss., Université Paris sciences et lettres, 2022. http://www.theses.fr/2022UPSLS004.
Texto completo da fonteDynamic covalent chemistry is an effective tool to synthetize complex architectural block (co)polymers which are difficult to achieve by conventional techniques. It permits also to develop materials that meet ecological and economic challenges (recycling, sustainability, cheap raw materials and products). In this work, we implemented imine bonds in amphiphilic comb-like copolymers and co-networks starting from PDMS with pendant amines and benzaldehyde-functionalized PEG oligomers. In a first part, we studied the properties of PDMS-r-PEG co-networks as a function of the imine crosslinking rate. The materials are flexible, little or no sticky and transparent. Thermo-mechanical analysis shows that they are micro-separated but with no long-distance order (AFM, SAXS). They can be thermally reprocessed and chemically recycled (acidic medium or in the presence of an amine), thanks to the reversible and exchangeable imine crosslinking points. In a second part, we studied the self-assembly in aqueous solution of PDMS-g-PEG comb-like copolymers with the degree of grafting of PEG chains. For a sufficient degree of grafting, the copolymers form colloidal suspensions which are stable over several months even though their shape / size change with the hydrolysis of the imine bonds. Their ability to encapsulate and release a hydrophobic compound, in single phase and in emulsion, has also been demonstrated
Muro, Eleonora. "Quantum Dots pour le Ciblage en Cellules Vivantes et la Microscopie HiLo Bi-couleur". Phd thesis, Université Pierre et Marie Curie - Paris VI, 2011. http://pastel.archives-ouvertes.fr/pastel-00631485.
Texto completo da fonteN'Guiambo, Roger. "Microfiltration transversale des suspensions colloïdales avec adjuvants de filtration". Vandoeuvre-les-Nancy, INPL, 1988. http://www.theses.fr/1988NAN10197.
Texto completo da fonteBouet, Cécile. "Synthèse et caractérisation de nanoplaquettes semi-conductrices : contrôle des dimensions, de la forme et de la composition". Phd thesis, Université Pierre et Marie Curie - Paris VI, 2013. http://pastel.archives-ouvertes.fr/pastel-00943691.
Texto completo da fonteBiben, Thierry. "Structure et stabilité des fluides à deux composants : des fluides atomiques aux suspensions colloïdales". Lyon 1, 1993. http://www.theses.fr/1993LYO10007.
Texto completo da fonteHurtrez, Guy. "Etude des copolymères poly(styrène-b-oxyde d'éthylène) : synthèses, propriétés colloïdales et tensio-actives". Mulhouse, 1992. http://www.theses.fr/1992MULH0257.
Texto completo da fonteLe, Roy Boehm Anne-Laure. "Mise au point et caractérisation de suspensions colloïdales submicroniques et de microspères lipidiques. . . : ... en vue d'en déterminer les potentialités". Lyon 1, 1999. http://www.theses.fr/1999LYO1T244.
Texto completo da fonteGirardon, Maxime. "Systèmes colloïdaux lipidiques pour l’administration par voie orale". Electronic Thesis or Diss., Université de Lorraine, 2019. http://www.theses.fr/2019LORR0236.
Texto completo da fonteUlcerative colitis (UC) is an Inflammatory Bowel Disease (IBD) and it is still nowadays incurable. Beyond the administration of anti-inflammatory drugs, including curcumin (CC), one of the pathways to be explored is the repair of the intestinal mucosa by an exogenous supply of phosphatidylcholine (PC) and lysophophatidylcholine, which are over 70% deficient in patients with RH. To address this issue, we were interested in the design of lipid systems for the oral delivery and allowing the simultaneous carry of CC and PC. We first explored the nature of the interactions involved between the two active ingredients within two model membrane systems, liposomal bilayers and monolayers (or Langmuir films). It turns out that the keto/enol equilibrium of curcumin and therefore the interaction with PC is influenced by both concentration and confinement. On the other hand, the addition of a ceride, cetyl palmitate, complexing curcumin allows, for some compositions, the miscibility with PC while stiffening the as obtained mixture. Based on these results, we formulated various dispersions of solid lipid particles, by varying the methodology of colloidal engineering, diffusion-solvent evaporation vs double emulsion and the nature of the stabilizer, emulsifiers vs nanoparticles. The suspension obtained by the double emulsion method appears as the most efficient in terms of encapsulation, protection in simulated gastric medium and sustained release of the active ingredients in a simulated intestinal medium. Finally, the ability of solid nanoparticles to stabilize the solid / liquid interface of SLNs, similar to the Pickering effect, has also been demonstrated. The entire study is a proof of concept regarding the potential of solid lipid nanoparticle suspensions for the oral administration of curcumin and exogenous phosphatidylcholine
Guignot, Sylvain. "Rôle de particules colloïdales sur la stabilité de mousses de décontamination". Thesis, Paris Est, 2008. http://www.theses.fr/2008PEST0240.
Texto completo da fonteThis study aims to highlight the stabilization of nuclear decontamination foam by hydrophilic and hydrophobic mineral particles. Hydrophobic particles consist of homogeneously-grafted colloidal silica, and we have examined their ability to make an ideal gas-liquid interface viscoelastic. Hydrophilic particles are micrometric agglomerates of fumed silica, which turn foaming solutions into thixotropic yield-stress materials. The resulting foams can retain up to 75 % of their initial liquid during several hours. These remarkable drainage kinetics are explained with regards to the confining of agglomerates, studied both in a specifically-developed rigid porous media and in a foam with mobile interfaces and size-controlled bubbles. A percolation threshold appears in the porous media but can not take place in the foam owing to the interfaces deformability. Liquid is retained in the porous agglomerates trapped within the foam channels. The whole results have been patented
Rouet, Pierre-Etienne. "Synthèse et assemblages covalents de particules à patchs : vers de nouvelles molécules colloïdales". Thesis, Bordeaux, 2018. http://www.theses.fr/2018BORD0103/document.
Texto completo da fonteThe concept of valence is well-known at the atomic level and is at the origin of the diversity and properties of covalent compounds (molecules, macromolecules, crystals). Nowadays, one of the major challenges is to decline this notion of valence at the scale of colloidal particles, which could become programmed elementary bricks, that is to say the raw material of new materials that would be obtained by spontaneous assembly. In this context, we have developed patchy particles with chemical and topological discontinuities at their surface that limit the number of neighboring particles and induce directional interactions with them. The objective of our work consists first in imitating simple hybridizations of the divalent (sp), trivalent (sp2) and tetravalent (sp3) carbon atoms. The silica particles containing a specific number of cavities in which residues of polystyrene chains are chemically and selectively functionalized. Colloidal molecules consisting of a patchy particle, in the center, surrounded by satellite nanoparticles in controlled number were obtained by covalent or supramolecular routes. These first clusters mimic the geometry of simple molecules such as CF4, BF3, CO2 or H2O. By differentiating batches of satellites either by their size or by their chemical composition, we have shown that it is possible to extend the formation of colloidal molecules to more complex AXnYm (n + m = 4) structures or chiral colloidal molecules. Finally, we have developed another way to obtain new colloidal atoms containing a precise number of surface patches with a controlled area
Kuntzmann, Alexis. "Synthèses de nanoplaquettes colloïdales II-VI et encapsulation par procédé aérosol-gel". Electronic Thesis or Diss., Sorbonne université, 2018. http://www.theses.fr/2018SORUS554.
Texto completo da fonteColloidal two-dimensional semiconductor nanocrystals have emerged as a new class of nanomaterials due to their unique optical, electronic and mechanical properties. Nanoplatelets have a one-dimensional confinement along their thickness, controlled at the atomic level, and thus an extremely narrow emission line width. These objects have been considered as potential candidates for the fabrication of optoelectronic devices. However, nanoplatelets have not demonstrated continuously tunable emission when compared to quantum dots, which exhibit a band gap that can be finely tuned by adjusting nanoparticle size. Moreover, shell growth on these objects, which has been show to improve their quantum yield, causes a strong red shift in the emission wavelength. Thus, the wavelength range of these structures ranging from 615 to 700 nm does not fulfill the requirements of display devices where green is also required. In order to observe a continuous blue shift of the absorption and emission wavelengths of the final structures, a new strategy consisting of incorporating sulfur into the cadmium selenide cores has been developed. In addition, a new method of encapsulation by aerosol-gel method promoting the implementation of nanoplatelets within optoelectronic devices is presented. Finally, the evolution of the optical properties of unmodified and encapsulated nanoplatelets exposed to high power photon flux was studied and compared
Desert, Anthony. "Colloïdes hybrides silice/polystyrène de morphologie contrôlée". Phd thesis, Université Sciences et Technologies - Bordeaux I, 2011. http://tel.archives-ouvertes.fr/tel-00949569.
Texto completo da fonteDijksman, Arjen Toni. "Spectroscopie de boîtes quantiques colloïdales de forme et taille contrôlée". Phd thesis, Université Pierre et Marie Curie - Paris VI, 2013. http://pastel.archives-ouvertes.fr/pastel-00876357.
Texto completo da fonteKim, Jongwook. "Elaboration, Propriétés optiques et applications de suspensions colloïdales de nanobâtonnets de LaPO4". Phd thesis, Ecole Polytechnique X, 2013. http://pastel.archives-ouvertes.fr/pastel-00948255.
Texto completo da fonteDufour, Marion. "Hétérostructures, dopage et chimie de surface : contrôle de la structure et des propriétés optiques de nanoplaquettes de chalcogénures de cadmium". Electronic Thesis or Diss., Sorbonne université, 2019. http://www.theses.fr/2019SORUS487.
Texto completo da fonteCadmium chalcogenide nanoplatelets present unique optical properties resulting from their atomically precise thickness control. They have emerged as a new promising class of nanomaterial for optoelectronic applications. The goal of this thesis is to promote new optical properties through the design and surface chemistry of nanoplatelets. Firstly, CdSe/CdSe1-xTex core/crown heterostructures were synthesized and showed bicolor emission at the scale of a single nanoplatelet. This bicolor emission results from a competition between the localization of the electron in the CdSe core driven by the conduction band offset and the direct exciton recombination in the crown favored by the high exciton binding energy. Silver doped nanoplatelets were synthesized in the second part. This doping, performed through partial cation exchange, creates a silver-related emissive state in the band gap. The amount of silver incorporated in the nanoplatelet allows a progressive control of the emission color from green to red thanks to the coexistence of the band edge and the silver related emission. The silver state is strongly bound and is located 340 meV above the bulk valence band. Finally, the modification of the surface chemistry with bromide and oleylamine reduces the surface stresses and improves the surface passivation. This leads to a shift, beyond the discrete confinement, of the emission wavelength and increases the quantum yield up to 75 %
Hernando, Louis. "Sédimentation de suspensions non-colloïdales poly-dispersés et concentrées". Thesis, Bordeaux 1, 2012. http://www.theses.fr/2012BOR14490/document.
Texto completo da fonteFrom toothpaste to must of fermentation passing by painting, bed of a river, propellant of an rocket engine and blood, suspensions are present in many uses of our everyday life. The control of their implementation requires comprehension of their behavior and constitutes one of the challenges of nowadays research. In this work of thesis, we were interested in the sedimentation process of concentrated suspensions of non-colloidal and inert particles whose size distribution is mono, bi or tri-disperse. Two types of sedimentation were studied: decantation and thickening. The objective is to do an experimental and in a lesser way numerical study to characterize sedimentation the most completly possible with a detailed attention to flow and deposit structure, concentration profiles and determination of sedimentation modes. Used experimental means are the usual techniques of two-dimensional measurement (laser velocimetry and direct visualization) which authorize the data acquisition for configurations where particles evolve in the plan. These laser techniques were improved to simultaneously follow various particles populations and access to various outpouts such as velocities field, local volumic fraction, and velocities of various sedimentation fronts. A simple numerical tool was also built using Stokesian Dynamics and seizing the main part of the physical phenomena driving sedimentation leading to the modeling of the hydrodynamic interactions
Prabhu, Achutha. "Agrégation irréversible par patchs de particules colloïdales : une étude par simulation numérique". Phd thesis, Université du Maine, 2012. http://tel.archives-ouvertes.fr/tel-00795636.
Texto completo da fonteDanglade, Cyril. "Etude par diffusion de lumière de suspensions colloïdales concentrées sous contrainte". Thesis, Limoges, 2015. http://www.theses.fr/2015LIMO0113/document.
Texto completo da fonteThis thesis is part of a fundamental experimental approach to the study of ceramics suspensions, through the establishment of a panel of dynamic light scattering (DLS) measurement to a flowing suspension. The study was performed on ceramic concentrated suspensions of nanometric silica and laponite in Couette geometry. The measurement technique by DLS provides local information such as the shear rate and the local velocity of the particles. Through these measurements and video observation, velocity profiles have allowed to understand the evolution of the rheological behavior of concentrated suspensions. Moreover, concentrated suspensions of laponite form a gel when these are at rest. If this gel undergoes shear, this one deconstructs to become a « liquid » suspension. However, the gel appears under shear and its formation was also observed by DLS and camera
Magnan, François. "Synthèse et caractérisation de systèmes colloïdaux à géométrie coeur/coquille d'indium-silice Vers une application en biodétection". Thesis, Université Laval, 2013. http://www.theses.ulaval.ca/2013/29953/29953.pdf.
Texto completo da fonteA notable application of nanomaterials is the use of metallic nanoparticles (NPs) as optical bioprobes in Raman or fluorescence spectroscopy detection schemes. Such a use is permitted by the plasmonic properties shown by these NPs upon light irradiation; the spectroscopic properties of these colloids are tuned through careful selection of the core’s composition, size and environment. Gold and silver are the two most commonly used metals for biodetection as they are easily prepared in nanoscopic regimes with defined shapes and sizes, as well as for their intense optical interactions with visible light. These metals are however not applicable at higher energy UV regimes, which would allow, for instance, the enhancement of the intrinsic fluorescence of proteins, a field of interest in biodetection which is hindered by the extremely low fluorescence signal of these biomolecules. We propose for such an application the use of indium-based plasmonic probes, as this metal has been shown to be active in the UV regime. This master’s thesis thus focuses on the preparation of core-shell colloids for an eventual use in biodetection. The indium cores are prepared in a single step which combines both polyol and hot-injection methods characteristics. By shuffling various synthetic parameters, indium cores approximately 9 and 70 nanometers (nm) wide are obtained. The larger cores, which should demonstrate a stronger fluorescence enhancement effect, are then covered with a silica shell through a single Stöber-like step. Again, controlling different synthetic parameters such was water content, silica precursor concentration, and Stöber system dilution allows to modulate the silica’s thickness between 4 and 40 nm. Such a thin silica shell on such a relatively small indium core is, at the best of our knowledge, still unprecedented. The synthesized core-shell colloids are characterized with UV-Vis spectroscopy, transmission electron microscopy and dynamic light scattering.
Tableau d'honneur de la FÉSP
Silvert, Pierre-Yves. "Préparation et caractérisation de poudres de métaux précieux obtenues par le procédé polyol". Amiens, 1996. http://www.theses.fr/1996AMIE0107.
Texto completo da fonteDe, Vos Caroline. "Synthèse de nanoparticules d'or et d'argent par microplasma à pression atmosphérique". Doctoral thesis, Universite Libre de Bruxelles, 2017. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/257288.
Texto completo da fonteDoctorat en Sciences
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Destribats, Mathieu. "Emulsions stabilisées par des particules colloïdales stimulables : propriétés fondamentales et matériaux". Phd thesis, Université Sciences et Technologies - Bordeaux I, 2010. http://tel.archives-ouvertes.fr/tel-00593686.
Texto completo da fonteVenerosy, Amélie. "Élaboration, caractérisation et étude des propriétés de particules cœur-coquilles de diamant". Thesis, Université Paris-Saclay (ComUE), 2018. http://www.theses.fr/2018SACLS514/document.
Texto completo da fonteSynthetic diamond is now considered in various fields of applications like optics, catalysis, biology or even electronic. Thin films can be synthesized by Chemical Vapor Deposition (CVD) or by High Pressure/ High Temperature (HPHT), while particles are produced by detonation synthesis or milling of bulk diamond. Nevertheless, among all these diamond materials, there is no material available combining sphericity, monodispersity and crystalline quality. This is the purpose of this thesis work. Core-shell systems made of nanocrystalline diamond shell surrounding a silica core have been synthesized, starting from nanodiamond-seeded silica particles. These particles have been grown in a dedicated home-made CVD reactor, specifically developed to treat powders. Varying the gas composition, the nature of the coating has been tuned, from nanocrystalline diamond to a hybrid material made of nanodiamond particles surrounded by organized graphite. Complementary techniques such as Raman spectroscopy and High Resolution Transmission Electronic Microscopy (HR-TEM) have been used to characterize the crystalline structures. Colloidal suspensions were also obtained with these new diamond core-shells, by oxidation of their surface. Dissolving the silica core, diamond shells were also synthesized, exhibiting stable colloidal properties. Preliminary studies on diamond core-shells performances are also presented in this manuscript: their photocatalytic properties toward CO2 reduction and their in-vitro cytotoxicity considering further biological applications. Finally, the manuscript also reports on the extension of the process to magnetic silica cores for the synthesis of magnetic diamond core-shells
Carl, Philippe. "Étude expérimentale et modélisation de la cinétique d'adhésion de particules colloïdales d'intérêt biologique aux interfaces solide/liquide". Vandoeuvre-les-Nancy, INPL, 1999. http://docnum.univ-lorraine.fr/public/INPL_T_1999_CARL_P.pdf.
Texto completo da fonteThis dissertation deals with the adhesion kinetics of synthetic colloidal particles and biological cells at a solid surface after sedimentation in a liquid. The experiments were carried out by means of a sedimentation cell observed with an optical microscope connected to a camera allowing to take images of the adsorbing surface at a constant frequency. An image analysis algorithm, capable of counting without ambiguity the particles adhering to the surface, was elaborated to determine precisely the kinetics of the irreversible adhesion of the particles on the adsorbing surface. Four types of synthetic particles, differing either by their diameters or by their densities, were used. The relative effect of the sedimentation under the influence of the gravity with respect to the Brownian diffusion is quantified by the dimensionless parameter R*. The measured kinetics were compared to the predictions of various models) this confrontation reveals the validity of the ballistic deposition model (where an infinitely intense gravity is assumed) for particles characterised by a high value of R*. As the value of R* decreases, the adhesion kinetics deviates from that predicted by this model. An original approach, which accounts;for the diffusion in a gravitational field of finite intensity and the formation of a multilayer, leads to a better reproduction of the experimental kinetics. The asymptotic domain, hence the jamming limit\coverage, are also influenced by the mutual electrostatic repulsion of the particles. The methodology developed for the synthetic particles has been applied to the study of the deposition of polymorphonuclear leukocytes (PMN). It comes out from the observations that their irreversible adhesion kinetics is practically identical to that of synthetic particles characterised by the same value of R*
Adumeau, Laurent. "Développement de stratégies de biofonctionnalisation de surface de nano-objets pour des applications biologiques". Thesis, Bordeaux, 2015. http://www.theses.fr/2015BORD0425/document.
Texto completo da fonteThe aim of this study was the design of nanoparticles for three different biologicalapplications: magnetic nanoparticles cluster for magnetic extraction of biological materials,multimodal contrast agents (MRI and near infrared fluorescence imaging) for atherosclerosisdiagnosis, and fluorescent silica nanoparticles with two different dyes for in vitro and in vivo tumorlabeling. One part of the project dealt with the developement of a new grafting method ofpoly(ethylene oxide) macromolecules onto nanoparticle’s silica surfaces (PEGylation) in order toobtain a high grafting densities. The obtained results have shown that this PEGylation reduces the nonspecificprotein adsorption allowing a better extraction and sorting efficiency, and also permitsnanoparticles to escape the surveillance of the immune system for in vivo tumor labeling. Therefore,the biomolecular recognition of the nanoparticles has been optimized by controlling the number ofconjugated biomolecules and by studying this biomolecular recognition using biophysical methods(SPR, QCM-D). Finally, the different nano-objects were evaluated in the context of their respectiveapplication
Bon, Saint Come Yémina. "Développement d’électrodes poreuses pour un bioréacteur pilote". Thesis, Bordeaux 1, 2011. http://www.theses.fr/2011BOR14370/document.
Texto completo da fonteThe present work deals with the development of the working electrode of an electrochemicalbioreactor. This device enables the green synthesis of high added value chemical compounds. As theelectrochemical synthesis is located at the interface of the working electrode, structural optimizationof this reactor key component is required in order to maximize the available active surface area.Elaboration of highly organized macroporous gold electrodes with a size required by the pilot reactordimensions were obtained with the Langmuir-Blodgett method that was used to assemble a colloidalcrystal as a template. The elaboration of the organized colloidal deposit is first followed by theelectrodeposition of the electrode material, then by the dissolution of the template. The immobilization of the complete bio-electrochemical system inside the electrode pores was investigated in order to prevent pollution of the final product medium by one of the catalytic chaincomponent. This also improves the device life time. Subsequently electrogenerated ultra-thin silicalayers and electrodeposited polymer matrices were studied in order to preserve and optimize the catalytic activity of the redox proteins. In order to enhance the electrocatalytic synthesis, mediatormodified gold nanoparticules were incorporated in the different immobilization matrices. This allowed to increase the area of the electrochemical interface. The combination of the nano-objectincorporation and electrode nano-structuring intensified by a factor of 170 the catalytic process
Die vorliegende Arbeit beschäftigt sich mit der Entwicklung einer Arbeitselektrode für einenelektrochemischen Bioreaktor, der die umweltfreundliche Synthese von wertvollen chemischenKomponenten ermöglicht. Da die elektrochemische Synthese an der Oberfläche der Arbeitselektrodestattfindet, ist es nötig, den strukturellen Aufbau der Schlüsselkomponente des Reaktors zuoptimieren und die aktive Oberfläche der Elektrode zu erhöhen. Mit Hilfe der Langmuir-BlodgettTechnik wurden kolloidale Kristalle erzeugt, die als Template dienten, um hochgeordnetemakroporöse Goldelektroden, deren Dimensionen von dem Pilotreaktor bestimmt wurden,herzustellen. Nach dem Erzeugen von geordneten kolloidalen Filmen wurde der Zwischenraumzwischen den Partikeln mittels elektrochemischer Abscheidung gefüllt und das Templateanschließend chemisch aufgelöst. In der Folge wurde die Immobilisierung des komplettenbioelektrochemischen Systems im Poreninnenraum untersucht, mit dem Ziel eine Verunreinigung desReaktionsmediums durch eine der katalytischen Komponenten zu verhindern. Die Lebensdauer derElektrode kann so zusätzlich erhöht werden. Es wurde untersucht, inwieweit durch elektrogenerierteultra-dünne Silikaschichten oder durch Elektroabscheidung erzeugte Polymerfilme die katalytischeAktivität der Redoxproteine erhalten und weiter optimiert werden kann. Goldnanopartikel, die miteinem Mediator modifiziert wurden, wurden in die jeweilige Immobilisationsschicht integriert, mitdem Ziel die Effizienz der elektrokatalytischen Synthese zu erhöhen. Auf diese Weise konnte dieaktive elektrochemische Oberfläche der Elektrode weiter erhöht werden. Die Kombination aus einernanostrukturierten Elektrode und Nanoobjekten die in die Immobilisationsschicht eingebettetwurden, führte zu einer Signalerhöhung des katalytischen Prozesses um mehr als eineGrössenordnung
Moreira, Da Silva Cora. "Développement d'une stratégie de synthèse de catalyseurs métalliques pour la croissance sélective de nanotubes de carbone". Thesis, université Paris-Saclay, 2021. http://www.theses.fr/2021UPASF013.
Texto completo da fonteIn the age of miniaturization of ever more powerful electronic components, carbon nanotubes (CNTs) are one of the most promising materials. The realization of transistors based on SWCNTs has become a real scientific and economic challenge. Unfortunately, the single-wall CNTs, essential to this nanotechnology, can be either metallic or semiconductor depending on their atomic structure and we do not yet know how to select them sufficiently efficiently during their synthesis. Numerous research teams have been working for nearly 25 years for this purpose. The growth technique that has shown the greatest selectivity is CVD (chemical vapor deposition) assisted by nanoparticles acting as catalysts. Based on theoretical studies demonstrating the importance of carbon solubility within catalysts for selective growth, several groups have focused on the use of bimetallic nanoparticles (NPs) composed of carbon-solubilizing atoms (Co , Fe, Ni) allied to atoms which do not dissolve it (Ru, W etc.), in order to be able to play on the carbon concentration of these nanoreactors at the time of growth. The aim of this thesis is to develop a strategy for the synthesis of metallic nanoparticles, of size, shape and controlled chemical composition, common to several catalytic systems, in order to be able to play on the mechanisms governing the growth of CNTs in a perfectly controlled manner. We propose here a method of colloidal synthesis at controlled temperature, making it possible to obtain NPs in solid solution, homogeneous in volume, shapes, sizes and controlled chemical compositions. This method allows the synthesis of nano-alloys, whether they are bi-, tri-, tetra-, or even pentametallic. The study of these particles by transmission electron microscopy has also enabled us to highlight the presence of a force on the surface acting on the colloidal NPs and on their lattice parameter. Finally, we tested these new particles by exposing them to a carbon gas in an environmental microscope (NanoMAX - LPICM and IPCMS - Strasbourg), which validated the viability of our colloidal pathway for the synthesis of carbon nanotubes and have followed in situ their growth
Dinh, Huy-Hong-Quan. "Kinetics, Coalescences and Rheology of Concentrated Emulsions during its separation : Experiments and Theories". Electronic Thesis or Diss., Université Paris sciences et lettres, 2021. http://www.theses.fr/2021UPSLS094.
Texto completo da fonteFor the oil industries, the development of enhanced oil recovery techniques represents a major challenge since these techniques increase oil yields on the company's fields. Hydrocarbons are produced in the form of emulsions which must be destabilized as quickly as possible. This process of separating the crude from the water is essential to control the costs of operations, linked to transport and refining. To speed up this separation step, chemical additives are used. The choices of the concentrations and types of additives used are mostly made empirically. Indeed, a thorough understanding, making it possible to select and predict the performance of such additives, has not yet been acquired.The aim of this thesis is therefore to take a first step in this direction. We therefore propose to study, using model systems, the destabilization of these in-situ emulsions as a function of various physicochemical parameters representative of the situations encountered in the operations in practice. This study aims to better understand the various physical phenomena involved in order to include the appropriate physics in the simulation tools allowing in the laboratory a better screening of chemical additives and their formulations in terms of performance of the selected product and the time required. to its selection.------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Teiten, Béatrice. "Etude du contrôle chimique des hydrosols d'argent en vue de l'exaltation de la diffusion Raman (SERS) de molécules cibles (uranyle, atrazine) : spectres anormaux". Nancy 1, 1998. http://www.theses.fr/1998NAN10213.
Texto completo da fonteBoussoufi, Félix. "Nanocristaux semi-conducteurs colloïdaux pour dispositifs opto-électroniques : synthèse et stabilité sous contraintes thermiques et optiques". Electronic Thesis or Diss., Sorbonne université, 2021. http://www.theses.fr/2021SORUS231.
Texto completo da fonteColloidal semiconductor nanocrystals have become during the last thirty years a class of materials that can address new technological solutions for many applications, such as light emitting diodes, solar cells, infrared photodetectors, medical imaging systems, etc. Nevertheless, these nanocrystals suffer from poor stability against external stress (heat, light, humidity, oxygen), limiting their use in many applications. Today, it is therefore necessary to study the physicochemical phenomena at the origin of their degradation and to propose new solutions to improve their stability. The main objective of this thesis was to develop an ink of lead sulfide quantum dots (PbS QDs) for a near-infrared photodetector, with stable optoelectronic properties under thermal stress (150 °C for 3 h). The manuscript first presents a study of nanocrystals films made of PbS QDs capped with halide ligands, NH4I and PbX2 (X = I, Br). The optical and photoconductive properties degrade rapidly under the effect of heat, mainly because of the formation of a Pb5S2I6 parasitic phase and of the coalescence of the nanocrystals. An ink of PbS QDs stabilized by CsPbI3 perovskite precursors was subsequently developed. This formulation provides more thermally stable nanocrystal films with better preserved optical, structural and photoconductive properties. These PbS-CsPbI3 QDs films were integrated into a near-infrared (940 nm) photodiode-type photodetector, demonstrating an external quantum efficiency of nearly 49% and a dark current of 10-5 A/cm2, after undergoing the thermal treatment of 150 °C for 3 h. Finally, a spray-drying polymer encapsulation method for CsPbBr3 perovskite nanocrystals is presented. The composite beads, made of acrylate-based polymers, possess a photoluminescence quantum yield of 35% with a fluorescence peak at 518 nm and a half-value width of 22 nm. The encapsulation of the nanocrystals allows an improvement of their photostability, with a stable green emission after 200 h under continuous illumination in an LED/nanocrystal downconverter device
Chopin, Thierry. "Etude de l'influence des paramètres de précipitation du gel d'hydroxyde de titane sur les caractéristiques de l'oxyde calciné". Mulhouse, 1986. http://www.theses.fr/1986MULH0003.
Texto completo da fonteMaillaud, Laurent. "Formulation d'encres conductrices à base de nanotubes de carbone pour le développement d'électrodes transparentes". Phd thesis, Université Sciences et Technologies - Bordeaux I, 2013. http://tel.archives-ouvertes.fr/tel-00939861.
Texto completo da fonteAtanase, Léonard-Ionut. "Contribution à l'étude des complexes Poly (vinyle alcool - vinyle acétate) / tensioactifs anioniques : caractéristiques colloïdales des nanogels et extension aux copolymères à blocs". Phd thesis, Université de Haute Alsace - Mulhouse, 2010. http://tel.archives-ouvertes.fr/tel-00562063.
Texto completo da fonteRamiandrisoa, Donatien. "Adsorption de protéines sur des colloïdes et agrégation induite". Phd thesis, Université Pierre et Marie Curie - Paris VI, 2014. http://pastel.archives-ouvertes.fr/pastel-00997448.
Texto completo da fonteRano, Simon. "Etude des propriétés de nanoparticules de LiCoO2 en suspension pour une application redox-flow microfluidique". Thesis, Paris 6, 2017. http://www.theses.fr/2017PA066197/document.
Texto completo da fonteThe aim of this work is to make a redox-flow battery that runs on lithium insertion material suspensions in order to increase the energy density of such systems. The use of microfluidic technics allows to solve the issues and limitations of ion exchange membrane by removing them. In the first part controlled size LiCoO2 nanoparticles are synthesized by hydrothermal route and dispersed into suspensions. The aggregation state of these suspensions are investigated using diffusion light scattering and transmission electronic cryoscopy. Rheological properties were also characterized for redox-flow use. The electronic transfer between a particle in suspension and the flow cell electrodes is crucial for their performances. This transfer is studied in the second part using the single event collision technic which consist of isolating individual aggregate electrochemical response at the surface of an ultramicroelectrode. This approach allows an extensive investigation of suspensions aggregates size, mobility and insertion reaction kinetic. Finally this works propose to replace the conventional ion exchange membrane by the mean of microfluidic technics. In co-laminar condition the fluid interface acts as a separation membrane to create a membrane-less redox-flow battery. The last part focuses on the fabrication of microfluidic cells and the behavior of suspensions in micro-channels
Cerbelaud, Manuella. "Hétéroagglomération de suspensions céramiques : une étude numérique". Limoges, 2008. https://aurore.unilim.fr/theses/nxfile/default/265324bc-02ff-4c5b-ab85-07aada762eb8/blobholder:0/2008LIMO4024.pdf.
Texto completo da fonteHeteroagglomeration in ceramic dilute suspensions composed of alumina and silica has been studied by means of two simulation methods : Brownian dynamics and global minimization. First, simulationswere applied to a system, inwhich alumina and silica particles have similar sizes. They allowed to analyze the composition and the structure of the agglomerates. Then, simulations were adapted to a second system, where the silica particles are sixteen times smaller than those of alumina. In this case, simulations showed that the silica particles adsorb on alumina and that the strongly charged alumina particles agglomerate via the silicawhich is placed between them. These agglomerates are very elongated although their equilibrium shapes are more compact. The experimental observations obtained in both systems are in agreement with the simulation results
Iazzolino, Antonio. "Engineering three-dimensional extended arrays of densely packed nano particles for optical metamaterials using microfluidIque evaporation". Phd thesis, Université Sciences et Technologies - Bordeaux I, 2013. http://tel.archives-ouvertes.fr/tel-01059235.
Texto completo da fonteXie, Wenbing. "Etude théorique et expérimentale de couplages chimico-mécaniques dans des systèmes associant une structure polyélectrolytique à une réaction enzymatique". Rouen, 1989. http://www.theses.fr/1989ROUES034.
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