Les solides divisés telles que les poudres pharmaceutiques nécessitent souvent des processus d'agrandissement de taille par agglomération pour améliorer leur comportement mécanique, notamment la coulabilité. Pour cette raison, le procédé de "granulation en voie sèche" est utilisé dans l'industrie pharmaceutique. Le procédé consiste à comprimer la poudre en la faisant passer entre deux rouleaux séparés par un entrefer, pour produire des plaquettes qui sont ensuite broyées en granulés et comprimés en compacts. Dans ce procédé, l'existence de différents modèles de compacteurs à rouleaux et de systèmes de broyage d’une part, et l'interaction entre les paramètres des procédés et des propriétés des produits (plaquettes, granulés et comprimés) d’autre part, rendent difficile la compréhension des phénomènes et des mécanismes sous-jacents. En particulier, le procédé entraîne une perte de résistance mécanique des comprimés formés à partir de granulés (comparativement à celles des comprimés de poudres non-granulés) et ce phénomène est encore mal compris. Ces aspects sont étudiés dans ce travail de thèse en menant des caractérisations expérimentales et des modélisations numériques permettant de mieux comprendre les modifications micro et macro structurales des poudres mises en forme par granulation sèche. Le but ultime est de progresser dans la compréhension des relations "propriétés des poudres - paramètres des procédés". Enfin, la compréhension des différences de comportement en compression de poudres granulées et non-granulées est menée à l’aide d’une modélisation du comportement dans le cadre de la mécanique des milieux continus poreux. / Particulate solids such as pharmaceutical powders often require size enlargement processes to improve the manufacturing properties like flowability. For that reason, dry granulation by roll compaction has been widely used in the pharmaceutical industry. The process consists of compressing powders between two counter-rotating rolls to produce ribbons that will be subsequently milled into granules. The obtained granules are tableted for oral dosage. In this process there are two main limitations: the existence of different designs of the roll compactors, milling systems and the interaction between process parameters and raw material properties are still a challenge and the roll-compaction process leads to an inferior tensile strength of tablets compared with direct compression. These aspects are investigated in this work. In the first part of this thesis, an analysis on the effect of different roll-compaction conditions and milling process parameters on ribbons, granules and tablet properties was performed, highlighting the role of the sealing system and the ribbon density distribution characteristics. In the second part, die compaction of roll-compacted powders, as the last stage of the process, is further investigated in terms of experimental analysis (effect of the granule size and composition and stress transmission measurements) and modelling the compaction behavior of granules.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / In this work, we study the crystallization process in the Fe40Ni40P14B6 and Fe76.5Cu1Nb3Si13.5B6 amorphous magnetic ribbons fabricated by melt spinning technique. The effect of crystallization on the magnetic properties is studied via MvsH data at room temperature carried out to as-cast and heated samples. X-ray diffraction (XRD), differential scanning calorimetry (DSC), thermogravimetry (TGA), magnetization of the magnetic field (MvsH) and magnetization versus temperature (MvsT) are reported. The values of Curie temperatures determined via TGA measurements are in agreement with that estimated via MvsT data. DSC measurements are carried out in isothermal and non-isothermal modes, and from the non-isothermal results, we define the temperatures of the isotherms. These isothermal data were fitted using the Johnson-Mehl-Avrami (JMA) model to Fe40Ni40P14B6 ribbon yielding an Avrami exponent, m > 2.5, to isothermal curves in the onset of crystallization process and 1.5 < m < 2.5 to intermediate regions of crystallization process. It is worth to comment that we are able to fit the non-isothermal curves for using the JMA model. XRD measurements taken after TGA measurement (T = 800oC) allow us to identify nanoparticles with Fe-Ni-based and Fe3B0.82P0.18 crystallographic phases to Fe40Ni40P14B6 ribbon and nanoparticles with Fe3Si crystallographic phase to the case of Fe76.5Cu1Nb3Si13.5B6 ribbon. The MvsH data are consistent with the crystallization processes which take place in amorphous magnetic materials. / Neste trabalho, nós estudamos os processos de cristalização em fitas magnéticas amorfas de Fe40Ni40P14B6 e Fe76.5Cu1Nb3Si13.5B6 fabricadas através da técnica de melt spinning. As medidas das curvas de MvsH a temperatura ambiente nas fitas como produzidas e tratadas termicamente permitiram estudar o efeito da cristalização nas propriedades magnéticas. As amostras foram caracterizadas através de medidas de difração de raios X (DRX), calorimetria exploratória diferencial (DSC), termogravimetria (TGA), magnetização em função do campo magnético (MvsH) e magnetização em função da temperatura (MvsT). Medidas de TGA mostraram-se eficazes para determinação da temperatura de Curie desses materiais, confirmadas pelas medidas de MvsT. Nós também realizamos medidas de DSC nos modos isotérmicos e não isotérmicos e, a partir dos resultados não isotérmicos, nós definimos as temperaturas de realização das isotermas. Em seguida, o modelo de Johnson-Mehl-Avrami (JMA) foi aplicado para a fita de Fe40Ni40P14B6. Para esses dados, o modelo JMA foi satisfeito e o valor do expoente de Avrami foi de m > 2.5 na região onde a curva de fluxo de calor aumenta e 1.5 < m < 2.5 nas regiões intermediárias entre o início do aumento da curva e pico de cristalização. Para as curvas não isotérmicas, o modelo de JMA não foi satisfeito. Para a fita de composição Fe76.5Cu1Nb3Si13.5B6 o modelo de JMA não foi testado. As medidas de DRX realizadas na fita de Fe40Ni40P14B6 após tratamento térmico identificaram fases nanocristalinas a base de Fe-Ni e contendo Fe3B0.82P0.18 e para a fita de Fe76.5Cu1Nb3Si13.5B6 a fase Fe3Si foi observada. As medidas de MvsH confirmaram as mudanças nas propriedades magnéticas de acordo com as frações cristalizadas dos materiais.

Le développement des lasers de fortes puissances réalisé au cours des dix dernières années a ouvert de nouveaux champs de recherche dans de nombreux domaines tels que la production de faisceaux de particules chargées. Lors de l'interaction d'un faisceau laser avec une cible, il est en effet possible de générer un faisceau d'ions ou d'électrons d'une large gamme énergétique dépendant de la puissance du laser et de la nature de la cible.Les physiciens qui étudient les interactions laser-matière montrent un grand intérêt à pouvoir réaliser des expériences avec une cible d'hydrogène pure de l'ordre d'une dizaine de micromètres d'épaisseur. Lors d'une telle interaction, un faisceau constitué uniquement de protons accélérés est produit. La protonthérapie est l'une des applications phares qui utilise les propriétés particulières des protons accélérés pour détruire des tumeurs cancéreuses. Cette technique, plus légère et moins coûteuse, pourrait remplacer dans les années à venir les gros accélérateurs de particules, situés en sous-sol des hôpitaux. Les travaux menés durant cette thèse ont permis de développer un moyen d'obtenir et de caractériser de telles cibles, et ce en utilisant un nouveau procédé d'extrusion.L'extrusion d'hydrogène solide requiert des fortes pressions (100 à 400 bar) et des basses températures (inférieures à 13 K). Les fortes pressions sont obtenues à l'aide des propriétés thermodynamiques du fluide. Dans un premier temps, de l'hydrogène est introduit puis solidifié dans la cellule expérimentale jusqu'à remplir celle-ci. La cellule est alors fermée et chauffée en partie haute afin de liquéfier l'hydrogène qui s'y trouve. La dilatation qui résulte du changement de phase, génère une pression sur l'hydrogène solide qui est situé sous le liquide. Cette pression permet d'obtenir la force nécessaire à l'extrusion qui est réalisée au travers d'une buse se situant à l'extrémité basse de la cellule. La principale différence avec un procédé classique d'extrusion est l'absence de parties mobiles.Des premiers rubans d'hydrogène d'une largeur de 1 mm et d'une épaisseur de 100 µm ont été obtenus et ont donné lieu à publication en mars 2014. Une évolution de la cellule et du cryostat a ensuite été réalisée dans le but d'atteindre des épaisseurs de rubans plus faibles (25 et 50 µm).Une buse cylindrique d'un diamètre de 140 µm a également permis d'obtenir de longs cylindres d'hydrogène solide et de comprendre le comportement de l'écoulement dans des géométries simples. En parallèle, de nombreuses simulations numériques ont été réalisées dans le but de caractériser ce comportement. Un modèle dédié a ainsi été établi, pour lequel les résultats expérimentaux et les simulations sont en bon accord.Un algorithme de mesure de vitesses d'écoulement, basé sur le suivi de défauts présents dans le film d'hydrogène a également été développé. Celui-ci est basé sur une technique d'inter-corrélation d'images. L'épaisseur du ruban est également obtenue par analyse d'images acquises. Ces résultats sont en adéquation avec la mesure du débit d'hydrogène pompé, réalisée en aval du cryostat.De nombreux laseristes ont alors manifesté leur intérêt autour de ce nouveau procédé et une collaboration a été mise en place avec l'équipe du laser PALS, à Prague, dans le but d'installer une nouvelle version du cryostat, capable de se fixer sur la chambre à vide de leur laser. Cette équipe, qui sera la première à tirer sur des cibles d'hydrogène solide courant novembre 2015, souhaite valider certaines théories et accélérer des protons en utilisant le principe de la TNSA (Target Normal Shealth Acceleration). Les laseristes du LULI (situés à Palaiseau, en France) sont également intéressés pour utiliser de telles cibles et une installation sur leur chambre laser a été planifiée au mois de janvier 2016. En parallèle, des physiciens de l'Institut Lumière Matière du CNRS de Lyon souhaitent également utiliser ces cibles pour générer des rayons X-UV. / The development of very high power lasers in the latest decade opened up new horizons in a various field, such as the production of accelerated ion beams. When a laser beam interacts with a target, the generated beam can contain energetic ions or electrons with a large energy spectrum (1–200 MeV). This energy distribution depends on the laser power and the nature of the target.Physicists studying the interaction between laser and materials are really interested in having very thin (10 µm) ribbons of solid hydrogen that could be used as a target. Indeed, during the interaction between a laser and such a target, a pure proton beam can be created. Protontherapy is one of the main potential applications which uses the special properties of accelerated protons to destroy cancerous tumor. This technique, lighter and cheaper, could replace in the next years huge particle accelerators situated underground the equipped hospitals. This PhD thesis was about developing a way to get and characterize such ribbons, using a new extrusion process.Extrusion of solid hydrogen requires a high pressure (10 MPa to 40 MPa) and a low temperature (below 13K). This is achieved by using the thermodynamic properties of the fluid. First, the cell is filled in with solid H2, then closed. Afterward, the upper part is heated to liquefy the solid. The expansion, resulting from the phase change creates a pressure on the solid hydrogen, located below the liquid. The extrusion is realized through a micron-sized hole at the bottom of the cell. The main difference with a classic extrusion process is the absence of moving parts.First solid hydrogen ribbons (1mm large and 100 microns of thickness) have been obtained in March 2014, leading to an article in a peer review (laser and particle beams (2014) 32,569-575, Continuous production of a thin ribbon of solid hydrogen). The use of a 50 micron nozzle was satisfying but it showed the limitation in the design of the cell, leading to an upgraded one, which will enable to extrude thinner ribbons.A cylindrical nozzle (140 microns diameter) has also been used to obtain long cylinders of solid hydrogen and to be able to understand the solid hydrogen flow in simple geometries. In parallel, several numerical simulations have been carried out to establish the flow behavior of solid hydrogen during the extrusion process. An “home made” model has been developed for which experimental results and numerical calculations fit quite well for different nozzles' geometries.Using small ribbon defaults as velocity tracers, cross-correlation algorithm has also been developed to measure the velocity during the extrusion process. The ribbon thickness is also extracted from image analysis. These results are also correlated by flowmeter measurements and appeared to be accurate.Several laser teams have shown a great interest for these results and a collaboration contract has been signed with the laser PALS team (Prague) to install an updated version of this cryostat, able to be plugged in their vacuum chamber. The team wants to shoot the solid hydrogen target to understand the laser/matter interaction and accelerate proton through the TNSA (Target Normal Sheath Acceleration) principle. It will be the first time such target will be shot. The installation of the cryostat is scheduled by the end of august and the first experiments are planned during november 2015. LULI's laser team at Palaiseau in France is also interested in using these targets and is planning to shoot them in January 2016. In parallel, CNRS physicists of the ILM (Institut Lumière Matière de Lyon) would like to use these targets to generate X-UV radiation.

Στη παρούσα διατριβή πραγματοποιήθηκε ανάπτυξη αισθητήρων που αποτελούνται από μαγνητοελαστικό έλασμα τύπου Metglas στην επιφάνεια του οποίου έγινε επικάλυψη με ευαίσθητο εκλεκτικό υμένιο. Στη μεγάλη πλειοψηφία των περιπτώσεων ως τέτοιο υμένιο χρησιμοποιήθηκε ζεόλιθος. Διαφορετικοί τύποι ζεόλιθων συνετέθησαν έπειτα από υδροθερμική σύνθεση και προσκολλήθηκαν ισχυρά στην εξωτερική επιφάνεια (και από τις δύο πλευρές) των Metglas. Ένας τέτοιος αισθητήρας συνδυάζει τις ροφικές ικανότητες του εκλεκτικού υμενίου με την ιδιότητα του Metglas να μετατρέπει φορτίσεις μάζας και αλλαγές των ελαστικών ιδιοτήτων του σε μετρούμενες μεταβολές της συχνότητας συντονισμού του. Η συνδυασμένη αυτή ικανότητα του αισθητήρα χρησιμοποιήθηκε για την ανίχνευση Πτητικών Οργανικών Ουσιών (VOC’s). Πιο συγκεκριμένα για τον ίδιο σκοπό χρησιμοποιήθηκαν υμένια ζεόλιθων (FAU, MFI και LTA) και πολυμερούς (Bayhydrol-110). Τα VOC’s των οποίων η ανίχνευση εξετάστηκε με τους παραπάνω αισθητήρες είναι: αιθυλεστέρας, πάρα-ξυλόλιο, όρθο-ξυλόλιο, βενζόλιο, κυκλο-εξάνιο, κανονικό-εξάνιο, προπάνιο και προπυλένιο. Δεύτερος στόχος της διατριβής ήταν ο υπολογισμός μηχανικών ιδιοτήτων των ζεόλιθων. Στη βιβλογραφία έχει αποδειχθεί ότι η ρόφηση αερίων επηρεάζει (εκτός από τη μάζα του) και τις μηχανικές ιδιότητες των ζεόλιθων μέσω της μεταβολής του μεγέθους της μοναδιαίας κυψελίδας των. Επομένως η ρόφηση αναμένεται να επηρεάζει εφαρμογές τους (π.χ ζεολιθικές μεμβράνες), των οποίων η απόδοση εξαρτάται άμεσα από τις μηχανικές τους ιδιότητες. Για το λόγο αυτό αναπτύχθηκε πειραματική μεθοδολογία με την οποία υπολογίζονται το μέτρο ελαστικότητας Ε των ζεολιθικών φιλμ, και οι τάσεις/παραμορφώσεις που αναπτύσσονται στο ζεολιθικό υμένιο κατά τη ρόφηση αερίων. Ο υπολογισμός για την εύρεση του μέτρου ελαστικότητας βασίζεται στη καταγραφή των μεταβολών της συχνότητας συντονισμού fR πολλαπλών αισθητήρων Metglas/ζεόλιθος διαφορετικού πάχους υμενίου ο καθένας. Η συγκεκριμένη μέθοδος γενικεύεται και βρίσκει εφαρμογή για τον υπολογισμό του μέτρου ελαστικότητας E του Young οποιαδήποτε μικροπορώδους ομοιόμορφου και καλά προσκολλημένου στην επιφάνεια του Metglas υμενίου. Ο υπολογισμός των τάσεων που αναπτύσσονται στο φιλμ κατά τη ρόφηση επιτυγχάνεται με χρήση δύο διαφορετικών μεθόδων. Η πρώτη μέθοδος, εφαρμόζεται σε αισθητήρες στους οποίους επικάλυψη με συνεχές υμένιο ζεόλιθου υπήρχε και από τις δύο πλευρές του Metglas. Με συνδυασμένη χρήση κατάλληλης θεωρίας και μαθηματικού μοντέλου της βιβλιογραφίας για τα μαγνητοελαστικά υλικά υπολογίζονται οι τάσεις που αναπτύσσονται στους ζεόλιθους FAU, LTA και σιλικαλίτη-1 κατά τη ρόφηση υγρασίας. Η δεύτερη μέθοδος υπολογισμού τάσεων εφαρμόστηκε σε αισθητήρα Metglas/MFI, στον οποίο επικάλυψη με συνεχές υμένιο ζεόλιθου υπήρχε μόνο από τη μία πλευρά του ελάσματος. Η μέθοδος εφαρμόζεται σε αισθητήρα Metglas/MFI κατά τη ρόφηση VOC’s, και βασίζεται στην ευκαμψία και ελαστικότητα που επιδεικνύει ο συγκεκριμένος αισθητήρας κατά τη διεργασία αυτή. Η διαφοροποίηση των δύο επιφανειών ως προς την ομοιομορφία του φιλμ του αισθητήρα, σε συνδυασμό με τη ρόφηση προκαλούν τη κάμψη του, ορατή ακόμα και με γυμνό μάτι, από το μέγεθος της οποίας υπολογίζονται οι τάσεις που αναπτύσσονται στο φιλμ του ζεόλιθου. Σε όλες τις περιπτώσεις ακολουθεί σύγκριση των πειραματικών αποτελεσμάτων μας με τη βιβλιογραφία. / In the current thesis the development of sensors comprised of magnetoelastic ribbon (Metglas) its surface was coated with selective sensitizing layer was examined. In most cases, zeolites were selected as sensitive layers. Different types of zeolites were synthesized and bounded in both outer surfaces of Metglas using the hydrothermal synthesis technique. Such a sensor combines the adsorptive abilities of sensitizing layer with the inner ability of Metglas to convert mass loadings and changes in the elastic properties in corresponding changes of the measured resonance frequency of the ribbon. That combined ability has been used for the detection of Volatile Organic Compounds (VOC’s). More particularly, for the same purpose zeolite layers (FAU, MFI and LTA) and polymer (Bayhydrol-110) have been used. The detected VOC’s are: ethyl-acetate, para-xylene, ortho-xylene, benzene, cyclohexane, n-hexane, propane and propylene. The second target of the current thesis was the calculation of mechanical properties of zeolites. In the literature has been proved that gas adsorption upon zeolites affects not only its mass but also its mechanical properties through the unit cell changes. Thus, adsorption is expected to affect applications such as zeolite membranes the performance of which is directly affected by their mechanical properties and possible changes. Hence, a new method is proposed which unable the calculation the Young modulus of zeolite films, and the stresses/deformations induced in the zeolite film upon adsorption. The calculation of Young modulus is based on the recording of resonance frequency changes of multiple sensors with different zeolite thickness each. The methodology is general and can be used for measuring Young modulus of any microporous film as long as it can be deposited as uniform layer on a magnetoelastic ribbon. The calculation of adsorption induced stresses is succeeded with two different methods. The first method is applied in sensors in which zeolite coating existed on both surfaces of Metglas ribbon. Combined use of appropriate theory and mathematical model from the literature for the magnetoelastic materials, stresses induced on FAU, LTA and silicalite-1 zeolites upon humidity adsorption were calculated. The second method was applied in Metglas/MFI sensor in which uniform polycrystalline MFI layer existed only from the one side of the ribbon. The method was applied during the adsorption of VOC’s and is based on the bending and elasticity shown by the sensor during the adsorption process. The differentiation of the two surfaces concerning the cohesion of the film, combined with adsorption phenomena cause remarkable bending, visible even with a naked eye, from the magnitude of which stresses induced on zeolite film are calculated. In all cases there is a comparison of our experimental results with corresponding from the literature.

abstract: Electronic devices based on various stimuli responsive polymers are anticipated to have great potential for applications in innovative electronics due to their inherent intelligence and flexibility. However, the electronic properties of these soft materials are poor and the applications have been limited due to their weak compatibility with functional materials. Therefore, the integration of stimuli responsive polymers with other functional materials like Silicon is strongly demanded. Here, we present successful strategies to integrate environmentally sensitive hydrogels with Silicon, a typical high-performance electronic material, and demonstrate the intelligent and stretchable capability of this system. The goal of this project is to develop integrated smart devices comprising of soft stimuli responsive polymeric-substrates with conventional semiconductor materials such as Silicon, which can respond to various external stimuli like pH, temperature, light etc. Specifically, these devices combine the merits of high quality crystalline semiconductor materials and the mechanical flexibility/stretchability of polymers. Our innovative system consists of ultra-thin Silicon ribbons bonded to an intelligently stretchable substrate which is intended to interpret and exert environmental signals and provide the desired stress relief. As one of the specific examples, we chose as a substrate the standard thermo-sensitive poly(N-isopropylacrylamide) (PNIPAAm) hydrogel with fast response and large deformation. In order to make the surface of the hydrogel waterproof and smooth for high-quality Silicon transfer, we introduced an intermediate layer of poly(dimethylsiloxane) (PDMS) between the substrate and the Silicon ribbons. The optical microscope results have shown that the system enables stiff Silicon ribbons to become adaptive and drivable by the soft environmentally sensitive substrate. Furthermore, we pioneered the development of complex geometries with two different methods: one is using stereolithography to electronically control the patterns and build up their profiles layer by layer; the other is integrating different multifunctional polymers. In this report, we have designed a bilayer structure comprising of a PNIPAAm hydrogel and a hybrid hydrogel of N-isopropylacrylamide (NIPAAm) and acrylic acid (AA). Typical variable curvatures can be obtained by the hydrogels with different dimensional expansion. These structures hold interesting possibilities in the design of electronic devices with tunable curvature. / Dissertation/Thesis / M.S. Chemical Engineering 2012

フランス国ボルドー大学との共同学位プログラムによる学位 / 京都大学 / 新制・課程博士 / 博士(エネルギー科学) / 甲第23585号 / エネ博第431号 / 新制||エネ||82(附属図書館) / 京都大学大学院エネルギー科学研究科エネルギー基礎科学専攻 / (主査)教授 石原 慶一, 教授 萩原 理加 / 学位規則第4条第1項該当 / Doctor of Energy Science / Kyoto University / DGAM

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This work studies the influence of field effect on large area 2 dimensional ribbons of fluids. A fluid of choice is confined in the channel of a metal-insulator-channel-insulator-metal architecture and is subjected to constant (d.c) or alternating (a.c) fields (de-pending on the application) along with a pressure drive flow. A general fluid would be composed of molecules having certain polarizability and be a dispersion of non-ionic and ionic particulates. The field effect response under pressure driven flow for this fluid would result in electrophoresis, electro osmosis, dielectrophoresis, dipole-dipole interaction and inverse electro osmosis phenomena. Using some of these phenomena we study applications related to desalination and energy harvesting with saline water as the ex-ample fluid for the former case, and solution processed poly vinyldene fluoride (PVDF) for the latter case. The geometrical features of \large area" and the \ribbon shape" can be taken advantage of to influence the design and performance for both applications. With regards to desalination, it is shown via experiments and theoretical models that the presence of alternating electric fields aid in ion separation along the flow when the saline water is subjected to laminar flow. Moreover, the power consumption is low due to the presence of the insulator. An average of 30% ion removal efficiency and 15% throughput is observed in the systems fabricated. Both performance parameters are discussion can be improved upon with larger channel lengths. The \2-D ribbon" and alternating field effect aid in achieving this by patterning the randomly distributed ions in the bulk into a smooth sheet charge and then repelling this sheet charge back into the bulk. The electric field exhibited by this sheet charge helps trap more ion sheets near the interface, thereby converting a surface ion trapping phenomena (when d.c is used) to a bulk phenomena and thereby improving efficiency. With regards to energy harvesting, a solution of PVDF in methyl ethyl ketone and 1-methyl-2-pyrollidone is confined to the \2-D ribbon" geometry and subject to high d.c fields. This aids in combining the fabrication, patterning and poling process for PVDF into one setup. Since the shape of the ribbon is defined by the shape of the channel, the ribbons (straight or serrated) can be used to sense forces of various magnitudes. More importantly experiments and theoretical models are studied for energy harvesting. Since the ribbon geometry defines the resonant frequency, large PVDF ribbon can be used to harvest energy from low frequency vibrations. Experiments show that up to 60 microwatt power can be harvested at 200 Hz and is sufficient to supplement the power for ICs.