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Institut des Sciences Moléculaires (Bordeaux)

Overview
Works: 175 works in 175 publications in 2 languages and 175 library holdings
Roles: Other
Publication Timeline
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Most widely held works by Institut des Sciences Moléculaires (Bordeaux)
Dendritic surface modification of photocatalytic nanoparticles for tumour therapy by Susanne Julia Koch( )

1 edition published in 2017 in English and held by 1 WorldCat member library worldwide

The occurrence of field cancerization is characteristic for tumours of the head and neck region. Due to these widespread premalignant and malignant alterations, it is frequently not possible to entirely remove the tumour by surgery. This results in a high risk of tumour recurrence. Therefore, this PhD research aimed to develop photocatalytic nanoparticles (NPs) as completion of the traditional tumour therapy. These NPs are supposed to be incorporated by tumour cells and to induce photocatalytic cell death by UV light activation. TiO2 with convincing photocatalytic properties and an average size smaller than 20 nm should therefore be synthesized. NP biocompatibility, their uptake into cells and an efficient tumour targeting should be guaranteed by surface modification of the particles with dendritic organic molecules that allow a precise control of the surface charge of the particles as well as antibody coupling.A further objective was the combination of therapeutic and diagnostic properties within the NPsystem realized for example via introduction of a luminescent dye. This research was carried out at the University of Bordeaux (synthesis of organic molecules for particle functionalization) in cooperation with the Fraunhofer Institute for Silicate Research ISC in Würzburg, Germany (nanoparticle synthesis)
Electrochemiluminescence at different scales : From new fundamental properties to surface-confined microscopy by Silvia Voci( )

1 edition published in 2019 in English and held by 1 WorldCat member library worldwide

L'électrochimiluminescence (ECL) est un phénomène d'émission de lumière obtenue suite à la génération d'espèces très réactives à l'électrode. Ces dernières vont subir une série de réactions de transfert d'électrons qui conduisent à la formation d'un état excité qui mène à l'émission finale de photons. La première partie de mon travail de thèse a porté sur l'étude de deux systèmes supramoléculaires. Les performances ECL d'un dérivé du spirofluorène et de trois composés modifiés avec un truxène comme partie centrale sont examinées. L'étude d'un deuxième système supramoléculaire, [18]-C-6bispyréne, a permis de démontrer une nouvelle propriété de l'ECL, maintenant capable de distinguer entre deux énantiomères, grâce à la détection du niveau de polarisation de l'émission ECL résultante. La combinaison entre ECL et systèmes confinés est présentée dans la deuxième partie de ma thèse. L'amplification du signal ECL par annihilation a été possible grâce à l'emploi d'un dispositif comprenant deux électrodes séparées par une distance de 100 nm. De plus, l'imagerie ECL a été utilisée pour mettre en évidence l'amélioration des performances de l'ECL bipolaire en utilisant une configuration comprenant un micropore planaire de 20 µm de long. Enfin, une nouvelle microscopie basée sur l'ECL a été développée. En perméabilisant la membrane cellulaire, l'ensemble de la cellule est visualisé par ECL. De plus, en se basant sur la distribution de l'émission ECL dans différents plans focaux, nous avons pu démontrer qu'une des caractéristiques fondamentales de cette nouvelle microscopie ECL est d'être confinée à la surface de l'électrode du fait des temps de vie limités des radicaux électro-générés. L'utilisation d'électrodes transparentes de nanotubes de carbone imprimés sur une lamelle de microscope a permis de réaliser l'imagerie ECL de cellules marquées aussi bien en réflexion qu'en transmission
Design and synthesis of ultra-bright organic nanoparticles (ONPs) for bioimaging by Paolo Pagano( )

1 edition published in 2017 in English and held by 1 WorldCat member library worldwide

Nowadays the use of bright luminescent nano-objects in biological environment is a topic that is gaining more and more importance, especially for biomedical applications such as imaging, the rapyand diagnostic. So far, numerous studies have been conducted with gold nanoparticles, silica nanoparticles (doped or functionalized with organic molecules), as well as semiconductor nanoparticles (quantum dots, i.e., QDs). However, most of these nanoparticles suffer from drawbacks (in terms of stability, biocompatibility, eco-toxicity or degradability). On the other hand, several nontoxic fluorescent molecular probes have been widely used, but most of the time their brightness remain modest in biological environments compared to QDs. Our idea is to engineer new organicchromophores with tunable emission wavelength (from visible to near infrared) for further preparation of organic fluorescent nanoparticles (so called FONs) that display giant one-photon and two-photonbrightness, as well as good colloidal and chemical stability, and suitable photostability for in vitro andin vivo imaging. As such, these FONs would represent interesting alternatives to QDs for use in bioimaging. This manuscript describes the synthesis and characterization of new classes of fluorescent molecules specifically engineered as building blocks for the fast preparation of such nanoparticles byself-aggregation in water. The FONs were fully characterized from both morphological and photophysical points of view and further used in bioimaging
La mise au point de méthodes thermiques et spectrométriques pour la caractérisation des catalyseurs pour le stockage de CO2 by José Flavio Benevides Ferreira( )

1 edition published in 2013 in English and held by 1 WorldCat member library worldwide

La capture de CO2 par adsorption sur des solides poreux (adsorbants) est une alternative prometteuse en raison de sa sélectivité et de sa faible consommation d'énergie. Nous avons étudié l'adsorption in-situ de CO2 sur des adsorbants solides en combinant la spectroscopie infrarouge par réflexion diffuse (DRIFT) avec la thermographie infrarouge afin de mieux comprendre les mécanismes d'interaction CO2-adsorbant et ainsi optimiser sa captation dans des procédés de capture en post-combustion. La thermographie IR est utilisée pour détecter la source de chaleur transitoire provenant de la surface de l'adsorbant au cours de l'adsorption de CO2. Un modèle de transfert de chaleur a été développé afin d'estimer les chaleurs d'adsorption. Un mini réacteur conçu pour la DRIFT nous a permis d'identifier les espèces adsorbées et d'étudier leur évolution sur la surface de l'adsorbant selon la température et l'atmosphère environnante. Enfin, le couplage d'informations provenant des deux approches nous a permis l'investigation haut-débit des paramètres clefs pour le choix des adsorbants les plus performants
Consideration of space debris in the life cycle assessment framework by Thibaut Maury( )

1 edition published in 2019 in English and held by 1 WorldCat member library worldwide

Several actors of or related to the European space industry, such as ArianeGroup and the European Space Agency (ESA), have identified life cycle assessment (according to ISO14040/44) as the most appropriate methodology to measure and minimise their environmental impact. Nevertheless, space systems deal with a strong particularity which adds new aspects considering the scope of the LCA framework. Space missions are the only human activity that crosses all segments of the atmosphere and stays “out” of the natural environment and ecosystems. Regarding space systems with a holistic approach, environmental impacts could occur not only in the conventional ecosphere but also in the outer space (i.e. the orbital environment).Consequently, the current scope of LCA studies should be broadened to take into account the on-orbit lifetime as well as the end-of-life disposal of the spacecraft. Yet, it is becoming a crucial point of the space mission design due to the future increase of the orbital population composed in a major part by space debris. In this way, LCA studies of space missions could indicate trade-offs not only between typical impact categories (toxicity and climate change for example) but also with regard to impacts generated in the orbital environment with a particular focus on space debris related impacts.Hence, the priority has been given to the integration of a new impact category called orbital space use in the life cycle impact assessment framework. To address the environmental burdens comprehensively in this new category, impact pathways linking elementary flows to environmental mechanisms (midpoint) and damages (endpoint) are developed within the Area-of-Protection 'Natural resources'. Space debris is identified as the main stressor of the orbital environment. Thus, 'characterisation factors' are defined and calculated at midpoint level to assess the potential impact of a space mission on the orbital environment. The methodology is applied to a case study to prove its applicability: the potential impact of a theoretical space mission is addressed through the comparison of three disposal scenarios. Also, a first attempt regarding the characterisation of the endpoint damage is provided taking into account the economic externalities caused by space debris. Finally, remaining methodological challenges and perspectives for future work are provided
Synthèses et propriétés de nouvelles structures à base de BODIPY pour l'imagerie bimodale TEP/IO et la génération d'oxygène singulet by Thifanie Christine( )

1 edition published in 2020 in French and held by 1 WorldCat member library worldwide

Medical imaging is a very important tool for the diagnosis of numerous diseases. The positron emission tomography (PET scan) is one of the most employed technique for its high sensibility, but the very short lifetime of the radionuclide used implies a very fast synthesis of the radioactive tracer.1,2 Optical imaging (OI) avoids the use of radioactive elements, but its limited sensibility in deep tissues can hamper its in vivo application. In order to obtain more modular probes depending on the need of the biologist (in vitro or in vivo studies), the development of new bimodal tracers is becoming an important research axis. In this context, new bimodal BODIPY-based molecules (fluorescent) that could be labelled by 11C (PET) have been synthesized. The different structures were conjugated to oestradiol to target the tumour cells of breast cancer. In vivo studies are being carried out to evaluate the biodistribution of the [13C]-labelled molecules. In parallel, their modification in photosensitizers for the production of singlet oxygen has also been considered for potential applications in the field of photodynamic therapy. On the other hand, several BODIPY-based photosensitizers have been synthesized and evaluated in a photooxygenation reaction, and their application to other types of reaction are in progress
Nouvelles perspectives dans les traitements classique et semiclassique de la dynamique réactionnelle by Wilmer Arbelo Gonzalez( )

1 edition published in 2013 in French and held by 1 WorldCat member library worldwide

The goal of chemical reaction dynamics theory is the quantitative description of reactive molecular collistions at the atomic scale. Since nuclear motions are difficult to study quantum mechanically, nuclei are often considered as classical object. However, quantum effects may play a major role in some situation, and the standard classical description does not take them into account. This thesis brings new perspectives on the inclusion into the classical treatment of one of the strongest qunatum effects, the quantization of reagents and products
Modélisation des relations structure / propriétés de transport de charge dans les matériaux pour l'électronique organique by Sai Manoj Gali( )

1 edition published in 2017 in English and held by 1 WorldCat member library worldwide

With the advancement of technology, miniaturized electronic devices are progressively integrated into our everyday lives, generating concerns about cost, efficiency and environmental impact of electronic waste. Organic electronics offers a tangible solution paving the way for low-cost, flexible, transparent and environment friendly devices. However, improving the functionalities of organic (opto) electronic devices such as light emitting diodes and photovoltaics still poses technological challenges due to factors like low efficiencies, performance stability, flexibility etc. Although more and more organic materials are being developed to meet these challenges, one of the fundamental concerns still arises from the lack of established protocols that correlate the inherent properties of organic materials like the chemical structure, molecular conformation, supra-molecular arrangement to their resulting charge-transport characteristics.In this context, this thesis addresses the prediction of charge transport properties of organic semiconductors through theoretical and computational studies at the atomistic scale, developed along three main axes :(I) Structure-charge transport relationships of crystalline organic materials and the role of energetic fluctuations in amorphous polymeric organic semiconductors. Kinetic Monte-Carlo (KMC) studies employing the Marcus-Levich-Jortner rate formalism are performed on ten crystalline Group IV phthalocyanine derivatives and trends linking the crystalline arrangement to the anisotropic mobility of electrons and holes are obtained. Subsequently, KMC simulations based on the simpler Marcus formalism are performed on an amorphous semiconducting fluorene-triphenylamine (TFB) copolymer, to highlight the impact of energetic fluctuations on charge transport characteristics. A methodology is proposed to include these fluctuations towards providing a semi-quantitative estimate of charge-carrier mobilities at reduced computational cost.(II) Impact of a mechanical strain on the electronic and charge transport properties of crystalline organic materials. Crystalline rubrene and its polymorphs, as well as BTBT derivatives (well studied high mobility organic materials) are subjected to mechanical strain and their electronic response is analyzed. Employing tools like Molecular Dynamic (MD) simulations and plane wave DFT (PW-DFT) calculations, unusual electro-mechanical coupling between different crystallographic axes is demonstrated, highlighting the role of inherent anisotropy that is present in the organic single crystals which translates in an anisotropy of their electro-mechanical coupling.(III) Protonation-dependent conformation of polyelectrolyte and its role in governing the conductivity of polymeric conducting complexes. Polymeric bis(sulfonyl)imide substituted polystyrenes are currently employed as counter-ions and dopants for conducting poly(3,4-ethylenedioxythiophene) (PEDOT), resulting in PEDOT-polyelectrolyte conducting complexes. Employing MD simulations and DFT calculations, inherent characteristics of the polyelectrolyte like its acid-base behavior, protonation state and conformation, are analyzed in conjunction with available experimental data and the role of these characteristics in modulating the conductivity of resulting PEDOT-polyelectrolyte conducting complexes is highlighted.The above studies, performed on different organic electronic systems, emphasize the importance of inherent characteristics of organic materials in governing the charge transport behavior in these materials. By considering the inherent characteristics of organic electronic materials and systematically incorporating them into simulation models, accuracy of simulation predictions can be greatly improved, thereby serving not only as a tool to design new, stable and high performance organic materials but also for optimizing device performances
Carbon dioxide and vegetable oil for the synthesis of bio-based polymer precursors by Margot Alves( )

1 edition published in 2016 in English and held by 1 WorldCat member library worldwide

Bien que thermodynamiquement et cinétiquement stable, le dioxyde de carbone est une molécule qui peut être convertie en carbonates cycliques à cinq ou six atomes respectivement au départ d'époxydes ou d'oxétanes moyennant l'utilisation d'un catalyseur approprié. Ces carbonates cycliques sont utilisés comme solvants verts, électrolytes pour les batteries au lithium ou comme intermédiaires pour la synthèse de polymères. Cependant, les performances catalytiques doivent être améliorées en particulier pour lecouplage du CO2 avec les huiles végétales époxydées ou les oxétanes. Dans ce contexte, nous avons développé un nouveau catalyseur homogène bicomposant organique composé d'un sel d'ammonium jouant le rôle de catalyseur et d'un co-catalyseur fluoré simple ou double donneur de liaison hydrogène. Dans un premier temps, l'efficacité de ces nouveaux catalyseurs a été évaluée et optimisée pour le couplage entre un époxyde terminal et le CO2 via des études cinétiques par spectroscopie FTIR ou Raman in-situ sous pression. Ces études ont démontré que l'utilisation combinée de sels d'ammonium et d'alcools fluorés induit un effet synergique permettant la fixation rapide et sélective du CO2 sur les époxydes modèles et les huiles végétales époxydées dans des conditions douces et sans solvant. L'utilisation de cette plateforme catalytique performante a ensuite été exploitée pour la synthèse d'oligocarbonates hydroxyles téléchéliques au départ d'oxétanes nettement moins réactifs que les époxydes. Ces oligocarbonates ont finalement été valorisés pour la synthèse de polyuréthanes CO2-sourcés par extension de chaines en présence de diisocyanates. En complément de ces travaux, une compréhension fine des mécanismes réactionnels a été réalisée via calculs DFT qui ont mis en évidence que l'efficacité catalytique de ces catalyseurs était liée à la stabilisation multiple des intermédiaires et états de transition par liaisons hydrogènes. A ce jour, via une étude comparative, nous avons mis en évidence que ce système catalytique bicomposant constitue un des catalyseurs organiques les plus performants pour le couplage du CO2 et d'époxydes et le seul système organique permettant la conversion d'oxétanes en synthons d'intérêt
Design de polymères conjugués pour des applications dans le photovoltaïque assisté par modélisation moléculaire by Alexis Fradon( )

1 edition published in 2016 in French and held by 1 WorldCat member library worldwide

During the last decade, a new kind of donor polymers for photovoltaic application have been intensively studied, the low band-gap polymers. They are based on repeating units associating two different moieties, one electron-rich (ER) and one electron-poor (EP), which allow to finely tune the molecular orbitals and to induce a delocalization of the exciton generated upon the photo-excitation process. A large variety of devices are based on such low band-gap polymers, with a power conversion efficiency record around 10%, and, to increase the efficiency, it is necessary to have a better understanding of these polymers during the photo-absorption phenomenon. Computational chemistry isa powerful tool that permits to predict different opto-electronic properties. For this work, we used Density Functional Theory and Time-Dependent Density Functional Theory to compute the optical properties of increasingly large oligomers involving various ER and EP subunits. The optical properties in the polymer limit were then estimated for the different systems by using an extrapolation scheme based on the Kuhn equation. This theoretical screening allowed us to select promising candidates based on benzodithiophene, benzothiadiazole and benzofurazan for syntheses, which were performed by a Stille coupling. The obtained polymers and size-controlled oligomers were further characterized by UV visible spectroscopy, fluorescence, size exclusion chromatography and NMR, in order to extractstructure-properties relationships and correlate experimental results to theoretical data
Electric field-generated asymmetric reactivity : from materials science to dynamic systems by Gabriel Loget( )

1 edition published in 2012 in English and held by 1 WorldCat member library worldwide

The phenomenon of bipolar electrochemistry generates an asymmetric reactivity on the surface ofconductive objects in a wireless manner. This concept is based on the fact that when a conducingobject is placed in an electric field, it gets polarized. Consequently, a potential difference appearsbetween its two extremities, that can be used to drive localized redox reactions. In the presentthesis, bipolar electrochemistry was used for material science and the locomotion of objects.So far, the majority of methods and processes used for the generation of asymmetric objects, alsocalled “Janus” objects, is based on using interfaces to break the symmetry. We developed a newapproach based on bipolar electrodeposition for generating this type of objects in the bulk. Using thistechnology, various materials like metals, polymers and semiconductors could be deposited ondifferent types of conducting particles. We also showed that bipolar electrochemistry can be used forthe microstructuration of conducting substrates.Motion generation by bipolar electrochemistry has also been demonstrated. Some of the Janusobjects synthesized by the previous approach can be used as microswimmers. The asymmetricreactivity that is induced by bipolar electrochemistry can also be used directly to generate motion ofnon-hybrid objects. With this concept we induced translations, rotations and levitations of carbonand metal particles
Développement d'une approche d'intégration des questions de morphologie urbaine dans l'évaluation environnementale des projets d'aménagement à l'échelle du quartier basée sur l'analyse de cycle de vie by Marc Lotteau( )

1 edition published in 2017 in French and held by 1 WorldCat member library worldwide

This work is a contribution to the environmental assessment of urban development projects in the upstream design phase. It focuses on integrating urban morphology issues with life cycle analysis (LCA) applied to the built environment at the neighborhood scale. The energy performance of buildings is partly determined by design choices relating to the urban form and its interactions with climate. The objective of this thesis is to provide to the design teams a way to take into account the influence of the urban form on the energy potentials of a neighborhood with a life cycle perspective.A preliminary study was conducted on two neighborhoods to detail the influence of the urban form on their energy potentials. An approach to modeling the embodied energy and embodied carbon of buildings is proposed. A sensitivity analysis and a contribution analysis of this model are performed on two generic building shapes. The results demonstrate the key influence of the shape of the buildings and a very strong link between the embodied energy and the building's compactness. An approach to assessing the passive heating potential and passive summer comfort potential at the neighborhood scale is also developed. It is based on the transformation of a neighborhood in an equivalent urban form (regular array of block buildings), and on the application of metamodels of a thermal simulation engine. The method is tested and discussed on a corpus of 45 case studies. These methodological developments are intended to be integrated into an existing tool for neighborhood LCA (NEST)
Synthèse totale de la vescaline, substance naturelle bioactive de la famille des ellagitannins C-arylglucosidiques by Antoine Richieu( )

1 edition published in 2017 in French and held by 1 WorldCat member library worldwide

Développement d'électrodes poreuses pour un bioréacteur pilote by Yémina Bon Saint Come( )

1 edition published in 2011 in French and held by 1 WorldCat member library worldwide

The 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
Nouveaux outils moléculaires photo-activables pour la délivrance contrôlée de principes actifs : De la conception aux applications biologiques by Victor Dubois( )

1 edition published in 2021 in French and held by 1 WorldCat member library worldwide

Nouveaux développements dans la chimie des sels de diazonium en catalyse organométallique : catalyse hétérogène en milieux aqueux by Francois Le Callonnec( )

1 edition published in 2014 in French and held by 1 WorldCat member library worldwide

Diazonium salts are reactive and versatile when used as electrophiles. Unfortunately, their reputation as instable compounds strongly limited their use in chemical synthesis. This work lead to the discovery of new procedure for a safer and more environmentally friendly use of diazonium salts in organometallic coupling reactions. We studied palladium catalised carbon-carbon coupling reactions and copper catalyzed C-H arylatons. A major part of this work is also focalized in the development of new heterogeneous catalysts. New catalysts for the Meerwein reaction were also discovered. Finally, the last part of this research work focused on new active heterogeneous supports as nanoreactors for organometallic reactions
Hémisynthèse de dérivés de l'acide grandiflorénique et évaluation préliminaire de leur activité biologique. by Nurby nahiely Rios tesch( )

1 edition published in 2017 in French and held by 1 WorldCat member library worldwide

This thesis work describes the hemisynthesis of grandiflorenic acid (GA) derivatives. GA natural product was first converted into ent-kaur-9(11),16 dien-19-ol, which was next esterified under Steglich conditions with a series of diversely substituted benzoic acids. To the twelve new compounds thus obtained, was added the preparation of the 9(11),16-dien-19-(2-methyl-5-nitro-1H-imidazol-1-yl)ethyl-entkaurene. All these new GA derivatives were carefully purified, and then fully characterized (IR, MS, 1D and 2D NMR) in the aim of their biological evaluation. The antibacterial activity was tested against several bacteria strains, such as Staphylococcus aureus, Enterococcus faecalis, Klebsiella pneumoniae, Pseudomonas aeruginosa, and Escherichia coli. The fungicide properties were evaluated against Candida albicans and C. krusei. The in vivo anti-inflammatory activity was studied on BIO:NMRI mice using the xylol-induced ear-edema test. Unfortunately, no antibacterial nor antifungal activity was exhibited by the grandiflorenic acid derivatives, but their anti-inflammatory activity revealed promising against acute inflammation, with the 9(11),16-dien-18-[2-(4-isobutylphenyl)propyl]- ent-kaurene being the best compound
Advanced Computer Simulations of Nafion / Water Systems by Gabriel Marchand( )

1 edition published in 2012 in French and held by 1 WorldCat member library worldwide

Perfluorierte Membranen werden insbesondere in Polymerelectrolyt-Brennstoffzellen(PEFC) eingesetzt. Das wohlbekannte Ionomer Nafion® (Dupont) ist wegen seinerhohen Protonenbeweglichkeit ein Referenzmaterial für solche Anwendungen in Brennstoffzellen.Die Membran separiert in Wasser oder anderen hydrophilen Lösungsmittelin eine hydrophobe Polymermatrix und eine hydrophile Subphase, die Cluster mitWasser und Ionen enthält. Dabei vergroeßern sich die Ausdehnung der Cluster und ihreKonnektivität mit zunehmendem Wassergehalt [1].Welche ist die Morphologie des Nafions und die Struktur des Lösungsmittels in diesenSystemen? Es ist jüngst anhand großer simulierter Systeme gezeigt worden [2], dassmehrere morphologische Modelle die experimentellen Streudaten wiedergeben können,was nahelegt, dass solche Streudaten alleine nicht geeignet sind, die wahre Strukturdes Nafion aufzudecken. Ein in [2] beschriebenes 'Zufallsmodell', d.h. das einzigeder untersuchten Modelle, das keine besondere Anfangsstruktur annahm, konnte dieexperimentellen Daten allerdings nicht wiedergeben.In molekularen Computersimulationen Konfigurationen zu erzeugen, die wirklich nichtmehr mit der angenommenen Anfangskonfiguration korreliert sind, bleibt eine echteHerausforderung. Die erreichbaren Zeitskalen sind zu kurz, um eine signifikante Bewegungdes Polymers (z.B Konformationsänderungen, Faltungen, usw.) zuzulassen. Indieser Arbeit wird daher ein neues Zufallsmodell für Nafion vorgestellt. Ein neuentwickelterAlgorithmus erzeugt Nafionketten mit zufälligem Wachstumspfad ausgehendvon zufälligen Anfangspunkten. Ein signifikanter Unterschied zu dem Zufallsmodellvon [2] ist, dass hier nicht versucht wird, die Systeme bei einer Dichte vergleichbarder experimentellen Dichte aufzubauen. Anstattdessen werden die Systeme, um alzustarkes Verknäuelung zu vermeiden, anfangs bei einer deutlich kleineren Dichte erzeugt.Nach äquilibrierung ist die Systemdichte wieder in etwa gleich der experimentellen.Wiewohl weitere Verbesserungen des neu Algorithmuses leicht ins Auge gefaßt werdenkönnen, so kann hier doch gezeigt werden, dass mit der gegenwärtigen VersionKonfigurationen erzeugt und äquilibriert werden können, die mit den verfügbarenStreudaten kompatibel sind. Zwölf große Nafion Zufallssysteme, mit verschiedenenAnfangspositionen der Atome, verschiedenem Wassergehalt und Längen der Seitenketten(Nafion/Hyflon) werden aufgebaut. Diese werden äquilibriert und mehrerezehn Nanosekunden lang simuliert. Nach der äquilibrierung sind die Strukturen, wieerwähnt, kompatibel mit den experimentellen Streudaten. Weiterhin wird ein Modellähnlich dem von Schmidt-Rohr und Chen [3], d.h. dem neuesten morphologischen Modellfür Nafion, studiert. Auch hier werden die experimentellen Streudaten zufriedenstellendwiedergegeben, daher die weiterhin bestehende Debatte über die Struktur desNafion.Die gefundenen übereinstimmungen lassen darauf vertrauen, dass eine detaillierte Analyseder simulierten Konfigurationen wissenschaftlich sinnvoll ist. So wird die Strukturder Systeme auf verschiedenen Längenskalen charakterisiert, zum Beispiel durch radialePaarverteilungsfunktionen (rdf), totale und partielle Strukturfaktoren (S(q)) sowieAnzahl- und Größenverteilungen hydrophiler Cluster (abhängig von der Definition einesClusters). Die Dynamik einzelner Spezies im System wird ebenfalls untersucht, zumBeispiel durch die Berechnung der mittleren quadratischen Verschiebungen (msd) undder Selbstdiffusionskoeffizienten. Diese Simulationen sind wahrscheinlich an der Grenzedessen, was heute mit 'all-atom' molekularen MD-Simulationen möglich ist. Ich vertrauedarauf, dass diese Arbeit dennoch einen Fortschritt in der aktuellen Debatte überdie Struktur und Dynamik dieser wichtigen Materiale darstellt
Immobilisation de dérivés du cryptophane-A sur des surfaces planes SiO2/or et or ainsi que sur des nanoparticules magnétiques by Elise Siurdyban( )

1 edition published in 2015 in French and held by 1 WorldCat member library worldwide

Réactions radicalaires multicomposant appliquées à la synthèse de lactones et pipéridinones fonctionnalisées by Laurent Huet( )

1 edition published in 2011 in French and held by 1 WorldCat member library worldwide

The construction of piperidinone and lactone scaffolds has been performed efficiently, combining radical and ionic processes. The synthesis of SEM-protected oximes by a multicomponent radical reaction enables, after hydrolysis of the oxime functional group, the access to a functionalized aldehyde. This compound is then converted into a lactone or a piperidinone by a ionic process.An approach minimizing the number of steps has been developed, thus allowing a rapid and convenient access to a large diversity of structures. These processes may involve up to five components
 
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Institute of Molecular Sciences facility in Talence, France

ISM

UMR 5255

Languages
French (12)

English (8)