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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
31

Conception, synthèse et étude de dérivés de C60 fonctionnalisés : applications biologiques et développement méthodologique / Design, synthesis and study of functionalized C60 : biological applications and methodological development

Sigwalt, David 26 March 2013 (has links)
Notre équipe a récemment développé une méthode polyvalente permettant de préparer des dérivés complexes de C60 hexa-adduits fonctionnalisés. Cette méthodologie permet d’obtenir des produits aux caractéristiques originales. Le C60 central agit comme un support central peu réactif, autour duquel des fonctionnalités sont réparties dans un espace octaédrique parfaitement défini. La première partie de ce travail de thèse a consisté à exploiter cette méthodologie pour créer des C60 hexa-adduits polycationiques aux propriétés de transfection remarquables. Dans un second temps, les dendrons polyamines synthétisés ont été mis à profit pour créer des structures supramoléculaires de C60 hexa-adduits, sous forme micellaire. Par la suite, l’étude de ces assemblages a orienté nos investigations vers l’élaboration de dérivés de C60 hexa-adduits mannosylés multivalents résultant d’un assemblage supramoléculaire, dont leurs possibles applications biologiques sont actuellement à l’étude. En parallèle une synthèse covalente a permis d’obtenir un «équivalent dendritique» de C60 hexa-adduit multimannosylé. Partant du constat que notre méthodologie est efficace principalement pour des dérivés de C60 hexa-adduits qui ont une régio-sélectivité particulière, la dernière partie a été consacrée au développement de nouvelles voies de synthèses qui pourront permettre de créer des dérivés de C60 avec un contrôle régio-sélectif original. / Our team has recently built a polyvalent method that gives complex functionalized C60 hexa-adducts. This methodology permits to obtain products with original features. C60 acts as an inert scaffold, around which functionnalities are distributed in a well-defined octahedral space. The first part of this thesis describes exploitation of this methodology to create polycationics C60 hexa-adducts, which have shown remarkable gene delivery capabilities. Next, the synthetized polyamine dendrons were used to build supramolecular structure of C60 hexa-adducts, as micellar forms. The study of these self-assembled structures has guided us to design micelles of mannosylated C60 hexa-adducts, which biological applications are under investigation. In parallel a covalent synthesis has furnished a dendrimers-like multimannosylated C60 hexa-adduct. Based on the observation that our methodology to create C60 hexa-adduct is efficient only for a specific regio-selectivity, the last part of this thesis was devoted to the development of new synthetic routes to obtain C60 derivates with an original regio-selective control.
32

Controlled synthesis and characterization of ru-fullerene nanostructures and their catalyticapllications / Synthèse contrôlée et caractérisation de nanostructures Ru-fullerène et leurs applications en catalyse

Leng, Faqiang 06 October 2016 (has links)
Le travail décrit dans cette thèse vise à produire des nanostructures bien ordonnées présentant une forte activité catalytique sur la base d’ensembles de nanoparticules de ruthénium et de fullerènes/fullerènes fonctionnalisés. Le Chapitre 1 présente une analyse bibliographique sur l’utilisation des fullerènes en catalyse hétérogène, en mettant en avant leurs propriétés particulières telles que la stabilité thermique, une grande capacité d'adsorption d'hydrogène et la capacité d’obtenir diverses coordinations. Le Chapitre 2 décrit la synthèse et la caractérisation de nanostructures Ru@C60 obtenues par la réaction de décomposition par au dihydrogène du complexe [Ru(COD)(COT)] en présence de C60. L'effet du solvant et des rapports de Ru/C60 utilisés durant la réaction ont été étudiés. Plusieurs caractérisations d’objets sphériques Ru@C60 et des calculs DFT nous permettent de proposer une voie pour leur formation. Le Chapitre 3 présente la préparation de nouveaux nano-assemblages obtenus à partir de [Ru(COD)(COT)] et de fullerènes fonctionnalisés en utilisant la même méthode décrite dans le chapitre 2. Tout d'abord la synthèse de fullerènes fonctionnalisés C66(COOH)12 est détaillée, puis la synthèse et la caractérisation des nanostructures Ru@C66(COOH)12 ont été étudiés. Le Chapitre 4 décrit l'utilisation de ces nanomatériaux en catalyse. Nous avons préparé trois Ru@fullerene: Ru@C60 dans du dichlorométhane, T-Ru@C60 dans le toluène et Ru@C66(COOH)12. Ensuite, l'activité catalytique et la sélectivité des catalyseurs préparés Ru@C60, T-Ru@C60 et Ru@C66(COOH)12 ont été étudiées pour l'hydrogénation du nitrobenzène et du cinnamaldéhyde. Des calculs DFT ont permis de rationaliser les résultats obtenus pour l'hydrogénation sélective de nitrobenzène sur Ru@C60. / The work described in this thesis aims to produce well-ordered nanostructures presenting high catalytic activity, on the bases of the assembly of ruthenium nanoparticles and fullerene/functionalized fullerene. Chapter 1 provides a review on the use of fullerene and fullerene-based materials in heterogeneous catalysis, emphasizing their specific properties such as thermal stability, high capacity for hydrogen adsorption and the ability of various coordination modes. Chapter 2 describes the synthesis and characterization of Ru@C60 nanostructures produced by the decomposition reaction of [Ru(COD)(COT)] in the presence of C60. The effect of the solvent and ratios of Ru/C60 on the course of the reaction have been investigated. Several characterizations of spherical Ru@C60 objects and DFT calculations allow us to propose a pathway for their formation. Chapter 3 presents new nano-assembly preparation based on [Ru(COD)(COT)] and functionalized fullerene using the same method as they are described in chapter 2. First, the synthesis of functionalized fullerene C66(COOH)12 is detailed, and then the synthesis and characterization of Ru@C66(COOH)12 is studied. Chapter 4 describes the use of these nanomaterials in catalysis. We have prepared three Ru@fullerene catalysts, which are Ru@C60 in dichloromethane, T-Ru@C60 in toluene, and Ru@C66(COOH)12. Then, the catalytic activity and selectivity of the prepared catalyst Ru@C60, T-Ru@C60 and Ru@C66(COOH)12 are studied for the hydrogenation of nitrobenzene and cinnamaldehyde. DFT calculations allow to rationalize the results obtained for the selective hydrogenation of nitrobenzene over Ru@C60.
33

Aggregation, adsorption and toxicity of fullerene C60 nanoparticles in the activated sludge process / 活性汚泥法におけるフラーレンC60ナノ粒子の凝集、吸着と毒性に関する研究

Yang, Yongkui 25 March 2013 (has links)
Kyoto University (京都大学) / 0048 / 新制・課程博士 / 博士(工学) / 甲第17539号 / 工博第3698号 / 新制||工||1563(附属図書館) / 30305 / 京都大学大学院工学研究科都市環境工学専攻 / (主査)教授 田中 宏明, 教授 米田 稔, 教授 伊藤 禎彦 / 学位規則第4条第1項該当
34

Elaboration de complexes porphyrines/C60 : Vers la synthèse de modèles des antennes collectrices d'énergie lumineuse et du centre réactionnel du système photosynthétique.

Walther, Mathieu 28 November 2006 (has links) (PDF)
Pour modéliser l'effet d'antenne et l'obtention d'un système à charges séparées, les deux étapes primordiales de la photosynthèse, nous avons associé des porphyrines et des fullerènes. Les porphyrines ont des propriétés structurelles et photophysiques proches de la chlorophylle.<br />Pour obtenir un effet d'antenne, nous avons réalisé plusieurs ensembles de porphyrines, avec toujours une porphyrine base-libre. Nous avons alors pu observer un transfert d'énergie des porphyrines métallées vers la porphyrine base-libre.<br />Pour obtenir un système à charges séparées, nous avons synthétisé des complexes entre ces ensembles multiporphyriniques, avec une porphyrine base-libre portant un éther-couronne et un dérivé de fullerène C60.<br />Il a été possible d'observer de fortes constantes d'association dans ces complexes, résultant de l'association d'interactions de type liaisons-H et d'interactions π− π entre le cœur de la porphyrine et la surface du C60, obtenant ainsi un bilboquet moléculaire.<br />Ces complexes, très stables, en solution nous ont permis d'obtenir de forts piégeages de l'énergie lumineuse de la porphyrine par le C60, soit par transfert d'électron, soit par transfert d'énergie.
35

Characterization and Quantification of Biological Surfaces Using Cluster ToF-SIMS with the Event-By-Event Bombardment/Detection Mode

Chen, Li-Jung 2012 May 1900 (has links)
Cluster ToF-SIMS (time-of-flight secondary ion mass spectrometry) operated in the event-by-event bombardment/detection mode has been applied to: 1) evaluate and screen the manufacturing quality of step-wise prepared micropatterned biointerfaces; 2) quantify the binding density of Au nanoparticles (AuNPs)-antiCD4 conjugates selectively attached on the cell surface; 3) elucidate the biological interaction of proteins and molecules by quantifying the fractional coverage of immobilized biomolecules; 4) enhance the accuracy of secondary ion identification of specific molecules. Briefly, our method consists of recording the secondary ions, SIs, individually emitted from a single projectile impact (C60 1,2+, Au400 +4). From the set of individual mass data, we select events where a specific SI was detected. The selected records reveal the SIs co-ejected from the nanovolume impacted by an individual cluster projectile from an emission area of 10-20 nm in diameter and an emission depth of 5-10 nm. The approach for quantifying the number of AuNPs or that of specific nanodomains is via the concept of the fractional coverage. The latter is the ratio of the effective number of projectile impacts on a specified sampling area (Ne) to the total number of impacts (No). The methodology has been validated with the determination of the number of antibody-AuNP conjugates on a cell, i.e. the number of disease related antigens on a cell via their specific binding sites with the AuNP-labeled antibodies. The number of AuNP-antibodies measured, ~42000 per cell, is in good agreement with literature results. The fractional coverage concept was also used to quantify several variants of biointerfaces. An example is the quantification of biotin and avidin immobilization as a function of the composition of silane substrates. The data collected in the event-by-event bombardment/detection mode expands the scope and quality of analytical information. One can identify SIs co-emitted with two specified SIs (double coincidence mass spectrometry) to inspect a specific stratum of a biointerface. A further refinement is the selection of events meeting a double coincidence emission condition. This mode enables the identification of nano-object of a few nm in size, which eliminates (anticoincidence) interferences from substrates.
36

Surface mapping based on the correlated emission of ions and electrons from hypervelocity C60 impacts

Eller, Michael 14 March 2013 (has links)
High resolution mapping of molecular species, specifically sub-micrometer spatial resolution mapping, is at the forefront of recent interest in Secondary Ion Mass Spectrometry (SIMS). Large projectiles, e.g. C60, Au400, display high quasi-molecular ion yields with reduced fragment ion yields compared to atomic or polyatomic projectiles. However, the application of large projectiles in a sub-micrometer beam is hampered by limitations in source brightness and angular emission characteristics which are incompatible with tight focusing. An alternate approach to a focused beam is to reduce the beam intensity to less than 1000 impacts per second (referred to as the event-by-event mode) and localize each projectile impact via an electron emission microscope. The characterization and performance of such an instrument for localizing individual projectile impacts of 15-75keV C60 with sub-micrometer spatial resolution are described here. The quest for localizing single cluster impacts requires an understanding of the relationship between SI and electron emissions. It was found that electron emission is observed independently of the number or type of secondary ion emitted for flat homogeneous samples. The independence of ion and electron emission confirms the rationale for using the emitted electrons to localize individual projectile impacts. Further investigation of electron emission revealed that the electron yield is characteristic of the class of sample investigated (e.g. metal, organic, semiconductor). The electron yield was found to depend on the size and topology of the sample. Additionally, the electron yield increases with increasing projectile velocity. The use of the novel instrumentation presented here, necessitated the development of custom acquisition and analysis software. The analysis of co-emitted species from nano-metric dimensions is enhanced with the ability to perform multiple coincidence/anti-coincidence calculations. New concepts were implemented for integrating localization and mass spectrometry via software solutions for image analysis and localization and subsequently correlation between emitted ions and electrons. The result is software and instrumentation capable of generating ion maps with sub-micrometer spatial resolution.
37

Determining the sp&#x00B2;/sp&#x00B3; bonding concentrations of carbon films

Hamilton, Trenton David 22 July 2005
Analysis of the electronic structures of nitrogen-doped, amorphous carbon samples and of nanodiamond films are carried out in order to determine their sp2 bonding concentration. The amorphous carbon samples under consideration are deposited onto polytetrafluoroethylene (PTFE) polymer substrates by hot wire plasma sputtering of graphite in varying nitrogen concentration atmospheres. The deposition or modification of the substrates surface may lend itself to increasing hardness and wear resistance. Eventually these polymer substrates may be used for applications in the field of biomaterials, focusing on cardiovascular surgery, where a low blood/surface interaction is important. The primary technique used in this study is x-ray absorption spectroscopy, measured at the Advanced Light Source synchrotron at the Lawrence Berkeley National Laboratory, Berkeley, USA. A method of analyzing these spectra was then developed to determine the sp2 bonding concentrations in carbon films. Through this newly developed analysis method, the sp2 bonding concentrations in these samples increases from 74 to 93% with growing nitrogen doping. The diamond films presented here are deposited on silicon wafer substrates in a methane atmosphere by microwave plasma deposition. Various deposition conditions, such as bias voltage and methane atmosphere concentration, affect the purity of the diamond film. This analysis reveals sp2 bonding concentrations in these samples from, typically, a few percent to 25%.
38

Determining the sp&#x00B2;/sp&#x00B3; bonding concentrations of carbon films

Hamilton, Trenton David 22 July 2005 (has links)
Analysis of the electronic structures of nitrogen-doped, amorphous carbon samples and of nanodiamond films are carried out in order to determine their sp2 bonding concentration. The amorphous carbon samples under consideration are deposited onto polytetrafluoroethylene (PTFE) polymer substrates by hot wire plasma sputtering of graphite in varying nitrogen concentration atmospheres. The deposition or modification of the substrates surface may lend itself to increasing hardness and wear resistance. Eventually these polymer substrates may be used for applications in the field of biomaterials, focusing on cardiovascular surgery, where a low blood/surface interaction is important. The primary technique used in this study is x-ray absorption spectroscopy, measured at the Advanced Light Source synchrotron at the Lawrence Berkeley National Laboratory, Berkeley, USA. A method of analyzing these spectra was then developed to determine the sp2 bonding concentrations in carbon films. Through this newly developed analysis method, the sp2 bonding concentrations in these samples increases from 74 to 93% with growing nitrogen doping. The diamond films presented here are deposited on silicon wafer substrates in a methane atmosphere by microwave plasma deposition. Various deposition conditions, such as bias voltage and methane atmosphere concentration, affect the purity of the diamond film. This analysis reveals sp2 bonding concentrations in these samples from, typically, a few percent to 25%.
39

Herstellung und Charakterisierung von organischen Schichtsystemen

Lehmann, Daniel 30 November 2005 (has links) (PDF)
Im Rahmen dieser Diplomarbeit wurde eine Ultrahochvakuumanlage für organische Molekularstrahldeposition (OMBD) konzipiert und gefertigt, die das Aufwachsen von einzelnen organischen Schichten bis hin zu komplexen Schichtsystemen auf geeigneten Substraten erlaubt. Mit einem ebenfalls konzipierten und gefertigten Probenhalter, sind elektrische Messungen in situ möglich. Für weitere Charakterisierungsmethoden, wie der spektroskopischen Ellipsometrie und der Reflexions-Anisotropie-Spektroskopie sind ebenfalls Optionen für in-situ-Messungen an der UHV-Anlage vorgesehen. Mit dieser Anlage wurden einzelne organische Schichten von Zinkphthalocyanin (ZnPc), Fulleren C60 und Bathocuproin (BCP) hergestellt, die anschließend mit spektroskopischer Ellipsometrie ex situ untersucht wurden. Mit der Herstellung organischer Solarzellen, auf Basis der zuvor hergestellten organischen Einzelschichten, konnte gezeigt werden, dass mit der UHV-Anlage komplexe organische Schichtsysteme erzeugt werden können, an denen in-situ-elektrische Messungen durchführbar sind. / Within the scope of this diploma thesis, a ultra high vacuum chamber for organic molecular beam deposition (OMBD) was designed and built, which allows the growth of single organic layers and complex composit layer structures. With an also designed and built sample holder, it is possible to make in situ electrical measurements. Single organic layers of zinc-phthalocyanine (ZnPc), fullerene C60 and bathocuproine (BCP) were deposited inside this chamber and characterized ex situ by spectroscopic ellipsometry. The preparation of an organic photovoltaic (OPV) cell based on the before characterized single layers, demonstrates that it is possible to deposit complex layer structures and characterize them electrical in situ.
40

Fullerene im Strahlungsgleichgewicht - Untersuchungen in einem Quadrupolspeicher

Decker, Silvio 16 December 2009 (has links) (PDF)
Das wissenschaftliche Ziel der Arbeit ist die Untersuchung von optischen und chemischen Eigenschaften von kohlenstoffhaltigen Teilchen im besonderen Fullerene bei hohen Temperaturen. Die Arbeit behandelt im Detail den Aufbau und die Charakterisierung einer Messapparatur zur Untersuchung von Fulleren-Kationen. Nach einer kurzen Einführung zum Thema und einer Beschreibung des Aufbaus der Arbeit beginnt diese mit der Charakterisierung der Apparatur als Ganzes und ihrer Elemente. Dazu gehört die weiterentwickelte Sublimationsionenquelle, der Quadrupolspeicher und der Ionendetektor. Es werden eingehende Messungen zur Speicherung und zum Nachweis der absoluten Zahl von gespeicherten Ionen vorgestellt. Weiterhin wird das optische Nachweissystem bezüglich der Sammelleistung und des Empfindlichkeit eingehend untersucht. Nach der Einführung in die Apparatur wird die Verteilung der Ionen im Speicher näher beleuchtet und gezeigt, dass ein optischer Nachweis der Zahl gespeicherter Ionen möglich ist. Außerdem wird gezeigt, dass es gelingt die kinetische Temperatur der Ionen im Speicher, durch die geometrische Vermessung der Ionenverteilung zu bestimmen. Im weiteren wird auf die thermische Emission heißer C60+ näher eingegangen. Dazu wird ein klassisches dielektrisches Modell zur thermischen Emission vorgestellt. Es werden Messprinzipien zur Temperaturbestimmung der lasergeheizten Ionen erörtert und Messungen zur Temperatur des Ionenensembles präsentiert. Weiterhin werden Messungen zum C2-Verlust von C60+ als Funktion der Temperatur vorgestellt. Die experimentell ermittelte Aktivierungsenergie der C2-Verlustreaktion mit Ea = 2,3...5,4eV zeigt deutliche Abweichungen zu bekannten Literaturwerten. Die Ergebnisse dieser Messung werden mit einer nummerischen Simulation zur Energieverteilung im Ionenensemble diskutiert. Die Arbeit endet mit einer Zusammenfassung und einem Ausblick auf weitere experimentelle Möglichkeiten der Messmethode. / The scientific goal of this work is the study of optical and chemical properties of carbon containing particles especially fullerenes at high temperatures. This work covered the construction and characterization of the measuring apparatus for the investigation of fullerene cations. It follows a characterization of the apparatus and its elements after a short introduction and a description of the structure of this work. This involved the further developed sublimation ion source, the quadrupole trap and the ion detections system. Extensive measurements of the ion trapping and the proof of the absolute number of trapped ions are presented. Further on the optical detections system is characterized in depth regarding the collection efficiency and sensitivity. After the introduction in the apparatus the distribution of the ions inside the trap is closer examined. The possibility of the optical detections of the number of trapped ions is shown. Additionally it is pointed out that the kinetic temperature of the ions can be extracted by geometrical measurement of the ion distribution. Further on it is enlarged on the thermal emission of hot C60. For this a classical dielectric model for the thermal emission is presented. Measuring principals of the temperature determination of laser heated ions are discussed and temperature measurements of the ion ensemble are presented. Measurements of the C2-loss as function of the temperature are presented. The results of the extracted activation energy of Ea = 2.3...5.4eV for the C2-loss reaction of C60+ shows a discrepancy to literature results. The results of this measurements are discussed with help of an numerical simulation of the internal energy distribution of the ion ensemble. This work closes with a summery and an outlook of further experimental potentialities of the measuring method.

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