Дисертації з теми "Élaboration de membranes"
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Kayser, Marie. "Élaboration de nouvelles membranes électrolytiques composites SPEEK/SILICE." Thesis, Université Laval, 2011. http://www.theses.ulaval.ca/2011/27958/27958.pdf.
Thevenot, Camille. "Élaboration de membranes polymères piézoélectriques souples en vue d’applications biomédicales." Thesis, Université de Lorraine, 2017. http://www.theses.fr/2017LORR0197/document.
The work presented here focuses on the preparation of a piezoelectric polymer material aimed to be the sensitive element of a strain sensor of biological tissues. This includes the study of the softening of the copolymer P(VDF-TrFE) necessary to be close of the mechanical properties of an artery, without reducing the piezoelectric coefficient. Plasticized P(VDF-TrFE) films with diethyl phthalate (DEP) were made according to different protocols including doctor blade technique or spin-coating and polarization under high voltage to activate the ferroelectric properties. Depending on the preparation conditions, two distinct structures were obtained with physical properties specific to each of them. For the first type of film, the study of the morphology and the hysteresis loops polarization-electric field showed a new structure of the material, with a demixing of the plasticizer in the matrix. In this case, the coercive field is strongly reduced which allows a decrease of the required high polarization voltage up to 40%, even if the film only contains 50wt% of P(VDF-TrFE). The second type of film, obtained after an annealing at lower temperature, has an almost homogeneous structure and properties close to a mixing law. The coercive field remains comparable to that of the pure P(VDF-TrFE) but the flexibility of the material is greatly increased. The study of the mechanical properties showed that the plasticizer can reduce the Young modulus to 40MPa for 30wt% of DEP in the film. In addition, the remanent polarization and the piezoelectric coefficient are also reinforced. In vitro and in vivo experiments, performed on arteries, of sensors based on these films demonstrated the high potential of the material to detect the strain of soft tissues and to function at biologic human frequencies
Chabert, France. "Élaboration par extrusion de membranes polymères pour piles à combustible." Grenoble INPG, 2004. http://www.theses.fr/2004INPG0132.
The aim of these studies was to process membranes by extrusion to be used in fuel cells. The functional polymers used are generally processed by polluting techniques like casting-evaporation, which are not easily transposable on industrial scale. Extrusion is a widely used shaping operation in the polymer processing industry. However, extrusion had not been used until now for arylsulfonic ionic polymers. In order to avoid any risk of degradation of the polymer during extrusion, it was necessary to define the best processing conditions. On one hand, the physicochemical characterization of the polysulfones (commercial) and sulfonated polysulfones (or synthesized by the project partners), were performed by determining their molecular weights and their thermal transitions. On the order hand, their flow behaviour was characterized over a wide range of temperatures and shearing rates using rheometric techniques. The combination of these two characterizations allowed to define the appropriate extrusion conditions. For the extruded films, the conductivities, measured by impedance spectroscopy were found to be similar with those of the membranes processed by casting-evaporation and close to those of Nafion® membranes. In addition, the incorporation of a proton-conducting filler and reinforcing fibres was also considered and the extrusion of these composite materials was validated. This work could be extended to other proton-conducting polymers, like polyetherethercetones and polyetherimides, whose membranes produced by casting-evaporation have already shown their performances in the fuel cells
Negrel, Jean-Luc. "Membrane protéique de nanofiltration : élaboration, caractérisation et propriétés de transfert." Montpellier 2, 1995. http://www.theses.fr/1995MON20065.
Tazi, Bouchra. "Élaboration et caractérisation d'une nouvelle membrane minérale conductrice ionique à structures dense et microporeuse." Montpellier 2, 1988. http://www.theses.fr/1988MON20138.
Tazi, Bouchra. "Élaboration et caractérisation de nouvelles membranes à base de Nafion et d'hétéropolyacides." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape8/PQDD_0020/NQ46640.pdf.
Lixon, Buquet Camille. "Élaboration et caractérisation de nouvelles membranes composites thermostables pour piles à combustible." Rouen, 2009. http://www.theses.fr/2009ROUES037.
The present work aims at finding alternative materials for the reference membrane for fuel cells, the Nafion® membrane from Dupont de Nemours. It concerns the effect of the sulfonation of polysulfone on the polymer segment motions, and that of modified laponite particles dispersed in sulfonated polysulfone on the water transport and the proton conductivity of these new hybrid membranes. The decrease, after sulfonation, in the cooperative motion average sizes allowed us to suggest a confinement of the glassy polymer chains in ionic clusters formed by interactions between sulfonic groups, in much a similar way as those formed in the Nafion® membrane. Moreover, the incorporated laponite-SO3H particles favor water diffusion and enhance the ionic conductivity of the composite membranes, by increasing the total content in ionic groups and the overall water affinity
Baradie, Bilal. "Membranes ionomères composites pour piles à combustibles H2/O2 : élaboration et caractérisation." Grenoble INPG, 1997. http://www.theses.fr/1997INPG0002.
Idrissi, Kandri Noureddine. "Élaboration et caractérisation d'une membrane minérale conductrice à base d'un mélange d'oxydes TiO2-RuO2." Montpellier 2, 1987. http://www.theses.fr/1987MON20158.
Ressam, Ibitissam. "Élaboration et caractérisation de nouvelles membranes composites à conduction protonique pour les piles à combustible." Thesis, Paris 6, 2017. http://www.theses.fr/2017PA066732.
The perfluoro-sulfonated ionomer membranes are employed as separators in many industrialapplications such as fuel cells, chloro-alkali industry, electrodialysis and gaining inclininginterest in aqueous rechargeable or redox-flow batteries where the knowledge of their ionictransport and transfer properties is fundamental.Particularly, Nafion is adopted as a referencemembrane for polymer electrolyte membrane (PEM) fuel cells due to its thermal stability andgood proton conductivity. However, Nafion membranes have several disadvantages such as a decrease in the proton conductivity at low relative humidity (<50%) and high temperatures(>80°C), and excessive dimensional changes due to the swelling/deswelling, leading tomechanical instabilities.To circumvent these problems, novel proton conducting membraneshave been developed, either by completely replacing or by using organic and/or inorganiccomponents to Nafion.3 In this regard, a large spectrum of membranes have been elaboratedconsidering many attributes such as high proton conductivity, physical separation between theanode and the cathode and fuel barrier characteristics, good chemical and physical stability andlow elaboration cost of the membrane. Two types of additives were examined to improve the performances, particularly : Membranes based on Nafion with Chitosan biopolymer. This naturel polymer is consideredas the second most abundant polysaccharide after cellulose.6 Chitosan improves the physical andchemical stability of the membrane in the presence of water, and it is considered as a less costlyadditive to Nafion7.The improvement of the proton conductivity with pristine chitosan isessentially challenging. Previous studies demonstrated that vehicularandGrotthuss mechanismjointly govern the proton transfer in chitosan membranes.In the vehicular mechanism, the protons diffuse together with solvent molecules in the form of hydronium ions byforming acomplex such as H5O2+ and H9O4+. In the Grotthuss mechanism, however, the protons jump fromone solvent molecule or functional group to the next by the continuous formation and breakingof hydrogen bonds. Membranes based on Nafion with Halloysite nanotubes (HNT). These clays confer to themembrane high proton conductivity by constructing large and continuous conductionpathways.These inorganic additives also improve the thermal and mechanical properties of PEM. Composite membranes of Nafion/Chitosan- SO3H and Nafion/HNT-SO3H are prepared. Theresulting composite membranes were studied by various conventional structural characterizationtechniques. H+ conductivity measurements were performed and the values obtained are higherthan those of pristine Nafion at various relative humidity (RH%) levels and temperatures (30°C-80°C). Our results highlight the beneficial character of functionalized chitosan biopolymer andHalloysite nanotube clays as additives to improve PEM performances
Mohd, Shafie Zulfida Mohamad Hafis. "Élaboration de membranes composites à fibres creuses à base de poly-4-méthyl-1-pentène et polydiméthylsiloxane comme couche intermédiaire revêtues d’une couche sélective de polyimide P84 pour la séparation de N₂/CO₂ et CO₂/CH₄." Electronic Thesis or Diss., Université de Lorraine, 2021. http://www.theses.fr/2021LORR0212.
Composite membrane structures are inevitable for the next step of mixed matrix membrane development as the commonly used asymmetric membrane design would mean majority of the fillers to be wasted in the bulk porous substrate layer. In this research, the possibility of using poly(4-methyl-1-pentene) (PMP) as substrate – gutter layer in composite membrane was compared with commonly used polydimethylsiloxane (PDMS) as gutter layer, supported on lithium chloride (LiCl) modified polyethersulfone (PES) porous substrate of varying surface pore architectures. Composite PES/PDMS was able to obtain permeance as high as 26.6 ± 2.6 GPU for N2 and 354.4 ± 27.9 GPU for CO2 at about 1 µm minimum coating thickness. Nevertheless, this value is lower than asymmetric dense skin PMP membrane at 84.6 ± 6.2 GPU for N2 and 607.3 ± 31.3 GPU for CO2. Despite that PDMS has intrinsic permeability far higher than PMP, PES/PDMS composite suffers from solution intrusion & geometric restriction problem at its dense – substrate interface, which reduces its permeance efficiency as low as only 4% of its supposedly ideal permeance, at low coating thickness. It is further elucidated that substrate surface uniformity also significantly affects the resulting composite permeance. In comparison, asymmetric PMP with thin dense surface layer was noted to be advantageous as the substrate – gutter layer as it mitigates the interfacial problem noted earlier for composite membranes while still being highly permeable to minimize resistance. Hence, N2/CO2/CH4 gases were chosen as the model permeants for further composite fabrication with P84 polyimide (PI) as selective layer. Nevertheless, low surface energy of PMP limit its compatibility to form a composite layer. However, it was noted that PMP is compatible to form a bilayer through dip coating with P84 PI, without the need for pre-treatment. Hence, P84 PI of various concentration was dip coated at 5 mm/s onto PMP-based dense skin hollow fiber membrane and tested for gas permeation performance. Results showed that ideal selectivity as high as 42.36 ± 19.08 for CO2/CH4 and 18.55 ± 6.06 for CO2/N2 was achieved at 14 wt.% P84 PI coating. Nevertheless, despite of PMP’s resistibility to the harsh N-methyl-2-pyrrolidone (NMP) solvent used for P84 PI solvation, introduction of P84 PI at low concentration (2 – 10 wt.%) damages the thin, dense skin layer of the PMP’s membrane surface which jeopardize the composite’s separation performance. It is hypothesised that P84 PI’s shrinkage during drying teared the underlying PMP layer which caused this degradation. Hence, there exist a minimum P84 PI polymer concentration in which a defect free selective layer can be made (which is at about 14 wt.%). At this concentration, dip coating speed can be manipulated to obtain a thinner defect-free selective layer suitable for composite membrane fabrication, although dewetting of the coating solution still occurred and magnified as the coating thickness is reduced
Emin, Clélia. "Élaboration d'un réacteur membranaire catalytique par fonctionnalisation de surface de membranes polymères et intégration de nanoparticules métalliques : application à la chimie douce." Toulouse 3, 2013. http://thesesups.ups-tlse.fr/2175/.
The aim of this work is synthesizing polymer-stabilized metallic nanoparticles inside functionalized polymeric membranes in order to develop catalytic membrane reactors and to test these reactors with model catalysed organic chemical reactions. In order to do so, polymeric membrane support (i. E. Polyethersulfone) is first functionalized by UV photo-induced grafting method with ionogenic polymers capable to immobilize nanoparticle precursors and retain nanoparticles. This surface modification was successfully performed with two types of anionic monomers, one cationic monomer and one zwitterionic monomer. During the process, the polymerization kinetic was found to be characterized by 3 steps: an induction time, a high polymerization rate and the total consumption of the monomer present in the solution. After the successful grafting, catalytic membranes were prepared by incorporating, or by generating in situ, metal catalytic nanoparticles. An effective incorporation of 5 nm palladium nanoparticles, well dispersed and mainly confined in the grafted layer without any aggregation, was found. Futhermore, it was possible to observe an impact of the cross-linked network and the polymer gel grafted layer on the final membrane metal loading. Moreover, results showed that nanoparticles are well trapped inside the membrane matrix inducing the development of a clean process. Finally, the catalytic activity of the different loaded membranes was mainly assessed by the reduction of p-nitrophenol into p-aminophenol and a conversion yield of close to 100% was found
Bertolotti, Bruno. "Élaboration de membranes échangeuses d’anions à architecture réseaux interpénétrés de polymères pour des batteries lithium-air." Thesis, Cergy-Pontoise, 2013. http://www.theses.fr/2013CERG0676/document.
This work focuses on the synthesis and characterization of polymer membranes to be used as anion exchange membranes for protection on an air electrode in a new lithium–air battery for electric vehicle. In these materials showing interpenetrating polymer networks (IPN) architecture, a hydrogenated cationic polyelectrolyte network, the poly(epichlorohydrin) (PECH), is associated with a neutral network, which can be either hydrogenated or fluorinated. First, the synthesis of the polyelectrolyte network and the membrane/electrode assembly were optimized. Second, a first IPN series associating the PECH network with a poly(hydroxyethyl methacrylate) network was synthesized. Third, the same PECH network was associated with a fluorinated polymer network. All the materials were characterized, and optimal synthesis methods as well as an optimal composition were determined for each association. The IPNs show improved properties compared with the single PECH network. The air electrode protected by these new anion exchange membranes shows improved stability in the working conditions of the lithium-air battery. Specifically, a lifetime of 1000 h was obtained when the electrode was modified with a fluorinated IPN, a 20-fold increase in the lifetime of the non-modified electrode
Li, King Wo. "Membranes polymères pour le traitement d'eau de production sur plateforme offshore." Thesis, Montpellier, 2018. http://www.theses.fr/2018MONTG046.
This project aims to develop a new generation of hydrophilic polymer membranes based on a biosourced polymer, Hydroxypropyl Cellulose (HPC), for application in the treatment of produced water. These polymeric membranes should replace on offshore platforms the conventional treatment processes because of their compactness, their lightness and their ability to effectively remove both oil and suspended particles. The membranes were developed using an original phase inversion method by increasing the temperature above the critical temperature (LCST-TIPS process). Two ways of membrane formation were investigated in this work according to the mode of chemical crosslinking considered, one in acid medium and the other in basic medium. Considering the acid route, the crosslinking was carried out using glutaraldehyde, while for the basic route it was carried out via PEGDE molecule. A fine control of the membrane formation process was conducted in order to control the kinetics of the whole elementary phenomena involved in the membrane morphogenesis (phase separation, solvent evaporation, and chemical crosslinking). The membranes were characterized via rheological monitoring, the analysis of the membrane morphology (SEM) and the filtration performances were investigated. The issue of hollow fibers fabrication has been also addressed during the thesis
Fabre, Jean-Paul. "Élaboration et caractérisation de nouvelles membranes minérales d'ultrafiltration en TiO2 et en ZrO2, réalisées par les techniques "sol-gel"." Montpellier 2, 1987. http://www.theses.fr/1987MON20004.
Moyen, Eric. "Conception et élaboration de substrats semiconducteurs nanostructurés : nouvelles applications en nanosciences." Phd thesis, Université de la Méditerranée - Aix-Marseille II, 2007. http://tel.archives-ouvertes.fr/tel-00193655.
Dans le cas des surfaces vicinales de Si(111), les propriétés cristallographiques intrinsèques du silicium permettent d'obtenir des motifs uni-dimensionnels sous forme de paquets de marches très réguliers, parallèles entre eux et équidistants. Ces gabarits sont fonctionnalisés par un dépôt d'or formant des réseaux unidimensionnels de plots de siliciures d'or de taille monodisperse, arrangés selon le motif pré-existant, et séparés par des terrasses riches en silicium. Lors d'un dépôt de cobalt sur de telles surfaces, seuls les plots possèdent des propriétés magnétiques.
Dans le cas du carbure de silicium (SiC), des réseaux de plusieurs cm2 de nano-canaux facettés, verticaux et de formes hexagonales sont crées par plusieurs méthodes. Le motif d'une membrane d'alumine poreuse est transféré par gravure ionique réactive sur la surface du SiC. Une érosion sous hydrogène à haute température donne aux pores leur forme facettée finale. Une technique alternative basée sur la réaction catalytique d'un réseau de plots de platine avec de l'hydrogène permet d'obtenir des substrats de SiC poreux à de basses températures d'érosion. Ces réseaux ont des applications potentielles dans le magnétisme et la biologie.
Baccar, Zouhair Majdi. "Etude et élaboration de nouvelles membranes inorganiques pour les microcapteurs de type IFSETs par implantation ionique et par photo-CVD." Ecully, Ecole centrale de Lyon, 1996. http://www.theses.fr/1996ECDL0022.
Viard, Antoine. "Structure, élaboration, propriétés et modification de surface de fibres creuses non-oxydes à partir de polymères pré-céramiques pour des applications membranaires." Thesis, Montpellier, 2016. http://www.theses.fr/2016MONTT243.
New ceramic materials have progressively emerged during the last century and continuously drew attention for diverse applications. This comes from the numerous and various properties they can exhibit. A great advantage of this type of materials is their mechanical, thermal and chemical stabilities, that makes ceramics of great interest for applications in harsh environments. This trend is especially perceptible in the field of membranes. In fact, despite their moderate cost, polymer membranes, which are mostly used, are very sensitive to the environment in which they are used and require to be replaced regularly. This justifies the search for alternatives and for more resistant materials like ceramics. Various shaping are possible to build a membrane, but among these, shapings in form of tubes have aroused particular enthusiasm because of their advantages in terms of surface/volume ratio and of lower mass transport resistance. Most of used and commercialized ceramics are based on oxide chemical compositions. This constitutes a drawback concerning the aging of the membranes and their stability at very high temperatures. Another type of ceramics, non oxide silicon based ceramics, exhibits very interesting properties which could eventually palliate these problems. In general, such materials are produced through the PDC route (Polymer Derived Ceramic route), especially because of the impossibility to proceed by more conventional methods for many of them. The principle of this bottom-up method is to synthesize preceramic polymers which can be converted into ceramics through an appropriate heat treatment. This enables a very good control of the chemical structure of the final ceramics and so a great versatility. Among these materials, the quaternary system Si-B-C-N has aroused big interest because of its extraordinary thermostructural properties coupled to chemical inertness. Thus, the present work has been focused on the preparation and application of this ceramic. Another advantage of the PDC route can be found in the possible shaping arising from the polymeric nature of the precursors. This method has been widely used for the production of thin ceramic fibers by using the melt-spinning process. The main objective of this thesis is the design of SiBCN ceramic hollow fibers and capillaries based on this shaping method. The aim is the preparation of very stable membrane supports at relatively low costs compared to conventional processes used to shape ceramic materials, often involving a sintering treatment at a very high temperature. These supports could be used in gas separation and water treatment applications. More precisely, chapter 1 presents a state of the art and allows to give the context and the motivations of this work. Chapter 2 discusses on the synthesis techniques and on the used methods. Chapter 3 is dedicated to the production of SiBCN ceramic hollow fibers by studying in details the precursors chemical structure used for this purpose before investigating its ceramic conversion and the evolution of the microstructure of the resulting ceramic. Chapter 4 is dealing with the production of SiBCN ceramic capillaries. The precursor used is characterized as well as the resulting ceramic. The last chapter gives some perspectives by proposing different methods of surface modifications of the hollow fibers and the capillaries presented in chapters 3 and 4
Rommelfangen, Marc. "Élaboration électrochimique et caractérisation ellipsométrique de matrices d'alumine : application à l'électroformage de nanofils de Bi2Te3." Metz, 2000. http://docnum.univ-lorraine.fr/public/UPV-M/Theses/2000/Rommelfangen.Marc.SMZSMZ0045.pdf.
Bourdon, Sylvie. "Développement d'une membrane à base d'un mélange de polymère, hydrophobe et de polymère hydrophile : élaboration, caractérisation et essais de filtration." Toulouse 3, 2002. http://www.theses.fr/2002TOU30248.
Barroil, Anne. "Étude et élaboration de microcapteurs à membrane cristalline sensible aux ions alcalins et à transduction par semiconducteur amorphe." Grenoble INPG, 1998. http://www.theses.fr/1998INPG0055.
Brigaudet, Mathilde. "Élaboration, caractérisation et optimisation de couches catalytiques cathodiques de piles à combustible PEM à partir d'aérogels de carbone." Phd thesis, École Nationale Supérieure des Mines de Paris, 2010. http://pastel.archives-ouvertes.fr/pastel-00564103.
Marconot, Olivier. "Croissance confinée de nanofils/nanotubes métalliques : élaboration et intégration dans les cathodes des PEMFC." Thesis, Université Grenoble Alpes (ComUE), 2016. http://www.theses.fr/2016GREAY095/document.
The two main drawbacks of Proton Exchange Membrane Fuel Cells (PEMFC) are the low electrode durability and the high platinum loading (electrocatalyst for oxygen reduction reaction). Currently, PEMFC electrodes, named as Pt/C, are made of platinum nanoparticles supported by carbon nanoparticles. The aim of this PhD work is to propose, elaborate and test in complete fuel cell new electrode nanostructure consists in self-supported platinum nanotubes. We target a reduction in the platinum loading and an increase in the electrode durability. In order to control nanostructure geometries, a porous alumina mold is used. This template is obtained by electrochemical anodization and vertically aligned nanopores are obtained. Platinum is subsequently deposited onto pore walls by e-beam evaporation or electrochemical deposition processes. After the hot pressing of the Nafion® proton exchange membrane, the porous alumina mold is etched and platinum nanotubes are stuck and self-supported onto the membrane. A part of this work is dedicated to the quantification of performances losses of Pt/C electrodes and nanostructured electrodes in complete fuel cell test operating conditions. Nanostructured electrodes exhibit high durability and easy oxygen access on catalyst surface compared to Pt/C electrodes. However, some losses kinetics remains due to the low catalyst specific area
Hugot, Nathalie. "Élaboration et caractérisation de nouveaux matériaux d'électrodes pour pile à combustible à membrane échangeuse de protons : catalyseurs à base de tungstène supportés sur un dérivé du graphite expansé." Thesis, Université de Lorraine, 2013. http://www.theses.fr/2013LORR0061/document.
This work is implicated in the development of carbon materials and of materials for energy applications. In the first part, we aim to totally or partially replace the platinum catalyst of the Proton Exchange Membrane Fuel Cell by less expensive and more abundant materials. In the second part, we optimize the catalytic sites accessibility for the reactants. WCl6 was impregnated on the Expanded Graphite derivated substrate by gaseous transport under chlorine pressure before being reduced and/or carburized in order to obtain tungsten derivatives (tungsten, tungsten carbides). The nature and size of the nanoparticles depend on the reducing or carburizing gas composition (H2 or H2/CH4 mixture) and the reaction temperature. Reduction is not complete until 500°C when using H2. W2C and WC mixtures are formed when using H2/CH4 mixtures (90/10, 85/15 or 80/20). The temperature increasing favours the sintering effect but not the complete carburization. All these obtained catalysts show low electrocatalytic performances when tested on a half-cell system. Platinum-tungsten hemicarbides catalysts were obtained by a successive deposition of PtCl4 and WCl6 while the reduction-carburization step was realized at 900°C under H2/CH4 mixture (85/15). These materials show higher electrocatalytic performances than a commercial platinum catalyst for an equivalent platinum ratio. The final part of this work concerns the carbon support functionnalization with sulfonate groups. Polystyrene sufonate grafting seems efficient for it helps to reduce the Nafion quantities used in the electrodes and to increase the electrocatalytic performances