University, Diss., 2005--Bremen. / Erscheinungsjahr an der Haupttitelstelle: 2004.

Universiẗat, Diss., 1998--Frankfurt (Main).

University, Diss., 2004--Karlsruhe.

Thesis (Ph. D.)--Lehigh University, 2006. / Includes bibliographical references and vita.

Thesis (Ph.D.)--University of Nebraska-Lincoln, 2006. / Title from title screen (site viewed May 9, 2007). PDF text: 143 p.: ill. (some col.) ; 4.21Mb UMI publication number: AAT 3237486. Includes bibliographical references. Also available in microfilm and microfiche formats.

Thesis (M.S.)--Virginia Polytechnic Institute and State University, 1994. / Vita. Abstract. Includes bibliographical references (leaves 90-93). Also available via the Internet.

Jusqu’à quelques années en arrière, pouvait encore prévaloir le préjugé que l’or cesse d’occuper une placeprépondérante dans l’histoire de l’art après que l’Antiquité et le Moyen Âge en aient fait le parangon de lavaleur, du beau et du divin. Si le Baroque et l’Art Nouveau offrent, manifestement, quelques magnifiquesoccurrences dorées, celles-ci pouvaient être considérées comme purement décoratives, ce qui permettaitparfois d’en disqualifier esthétiquement les périodes et les styles. Un examen objectif de la production artistique de la période moderne et contemporaine montre pourtant que, si l’étalage de l’or semble incompatible avec certaines thèses des avant-gardes artistiques en raison des connotations symboliques (principalement religieuses et politiques) attachées à son prestige et à sa préciosité, les artistes n’ont, de fait, jamais renoncé à en faire usage, encore que de façon plus ou moins subreptices. L’ambition de cette étude est de montrer que l’usage de l’or dans le monde de l’art de la période récente, s’il répond à des programme esthétiques singuliers et, parfois, contradictoires entre eux, partage aussi le fait qu’il vise toujours à produire un maximum d’effet sur ses usagers (artistes et spectateurs). C’est pourquoi nous utilisons ici la formule « aurum ex machina » car il nous semble que l’or, tel le dieu antique qui vientartificiellement dénouer la représentation (« deus ex machina »), arrive toujours à brûle-pourpoint dans laproduction ou la carrière d’un artiste plasticien de manière à sidérer (par sa beauté, sa brillance, sonintelligence, etc.) celui qui en perçoit sensiblement l’intensité. À travers de nombreux exemples, c’est cefonctionnement machinique de l’or que nous tentons d’analyser en déclinant plusieurs modalités d’action del’or dans l’art contemporain et en distinguant, de manière empirique, ce qui relève du concept (l’or commemachine réfléchissante), de la performance (l’or comme machine spectaculaire) et de l’érotisme (l’or commemachine désirante). Pour autant qu’on en puisse juger, le début du XXIe siècle, marqué, à la fois, par untriomphe éhonté et une crise profonde du capitalisme, offre aux artistes d’aujourd’hui, la perspective, à la foisdécomplexée et plus complexe que jamais, d’un or qui, pour être vraiment contemporain, n’en reste pas moins éternel / Until very recently, it was believed that gold no longer held a prominent place in the history of art after theAntiquities and the Middle Ages as the paragon of value, beauty and divinity. If Baroque and Art Nouveaudisplayed several magnificent, golden works, these were purely decorative and offering, sometimes, theopportunity to critique the aesthetics of the period and the style of the time. An objective consideration of artistic production in the modern and contemporary periods shows that, if the display of gold appears incompatible with certain theories of the avant-garde, because of it’s symbolic connotations (principally religious and political) linked to its prestige and value, artists never stopped using it, even though it was used more or less surreptitiously.The goal of this study is to show that, even if part of a specific aesthetic, and sometimes contradictory, program,the recent uses of gold in the world of art share the objective of producing the maximum effect on users(artists and spectators). This is why I use the formulation aurum ex machina because it seems that gold, like theGod of antiquity who arrived on scene at the last minute to magically resolve the crisis at hand, deus exmachina, the turn to gold always arrives at a critical moment in the production or the career of an artist who isovercome by the material’s beauty, radiance, intelligence, etc. and who feels overcome by it’s intensity.Exploring numerous examples, I follow the machine like workings of gold and analyze the different ways thatgold functions in contemporary art. In an empirical manner, I distinguish between the implications of gold as aconcept (gold as a reflecting machine), as a performance (gold as a spectacular machine) and as eroticism (goldas a desiring-machine). For as much as we can tell, the beginning of the 21st century is marked both by ashameless triumph and a profound crisis of capitalism, which offers today’s artists a perspective on gold that is uninhibited but more complicated than ever, still contemporary and always eternal

Engineered nanomaterials (ENMs) are currently used in a wide range of manufacturing processes and applications thanks to the numerous technical and economic benefits derived from the incorporation of ENMs in these processes. Accompanying these benefits are the potential toxicity of ENMs to humans and the environment. Previous research has shown that ENMs display strong toxicity to plants. Earlier research suggested that physicochemical properties of ENMs such as their size, shape, and surface properties considerably affect toxicity; however, the unique physicochemical properties of ENMs affect their phytotxicity to plants is still unknown. This research evaluated the phytotoxicity of silver and gold nanoparticles to lettuce plants in both sand and hydroponic conditions by monitoring a wide range of plant physiological parameters after their exposure to these nanoparticles with two coating materials (citrate and polyvinylpyrrolidone) and three shapes (sphere, wire and plate) at 200 and 1000 µg/L concentrations. The result from lettuce in hydroponics showed that spherical silver or gold nanoparticles with both coatings did not affect biomass significantly, but both of silver and gold nanoparticles at 1000 µg/L slightly reduced the biomass compared to the control lettuce. The effect on root leakage was similar, but spherical silver nanoparticles had slightly higher damage due to root leakage than gold nanoparticles at the same concentration. The lettuce treated to citrate-coated gold nanoparticles significantly reduced chlorophyll content compared to citrate-coated silver nanoparticles. Secondly, when it came to the surface coating, the plant exposed to 1000 µg/L spherical citrate- coated silver or gold nanoparticles had higher root leakage compared to PVP-coated nanoparticles. Both of 1000 µg/L spherical citrate-coated silver nanoparticles and gold nanoparticles significantly reduced chlorophyll content compared to PVP-coated nanoparticles. Thirdly, for different shapes of PVP-coated silver nanoparticles, the plant exposed to plate shaped and sphere shaped silver nanoparticles had significantly lower biomass compared to the wire shaped silver nanoparticles. The plant exposed to spherical silver nanoparticles had the lowest chlorophyll content between plate shaped and wire shaped silver nanoparticles. In addition, the result from lettuce in sand medium showed that the biomass production and the root leakage showed no significant difference between spherical citrate-coated, spherical PVP-coated, and silver ions at 200 µg/L. In conclusion, different nanoparticles affected different physiological processes of plants differently.

La synthèse de nanoparticules (NPs) d’or fonctionnalisées en phase aqueuse est encore aujourd’hui un enjeu majeur de la recherche dans le domaine des nanomatériaux. Depuis les travaux de J. Turkevich de 1951, la synthèse utilisant le citrate comme ligand et agent réducteur est la méthode de choix pour obtenir des NPs d'or. Cependant cette synthèse nécessite une étape supplémentaire de modification de surface par échange de ligand, pour pouvoir accrocher des molécules d’intérêt. Afin de simplifier la procédure, notre projet propose de synthétiser en une seule étape des NPs qui possèdent un groupement permettant une post-fonctionnalisation. La nouvelle voie de synthèse fait intervenir des composés bifonctionnels de la famille des 1-hydroxy-1,1-méthylène bisphosphonates (HMBP). Ainsi la base conjuguée de l'acide (1-hydroxy-1-phosphonopent-4-ènyl) phosphonique (HMBPène), qui possède une fonction éthylénique terminale nous a permis d'obtenir des dispersions de nanosphères de tailles contrôlées et nous avons pu rationaliser le mécanisme de synthèse utilisant ce type de molécules. Nous avons ensuite évalué plusieurs modalités de post-fonctionnalisation de notre nanoplateforme et validé une approche par chimie « Click » la via cycloaddition de composés tétrazine. En utilisant une nouvelle classe de HMBP couplés à une chaine polyéthylène glycol, des NPs stables en milieu physiologique ont pu être synthétisées selon le même modèle. Elles offrent également des possibilités de post-fonctionnalisation par couplage carbodiimide, que nous avons illustré par le couplage d'un fluorophore. Nous développons en dernière partie les résultats préliminaires sur deux types NPs d'or synthétisées à l'aide des HMBP pour des applications thérapeutiques. / In the ever growing fields of nanoscience the control of the synthesis of gold nanoparticles (GNPs) owing to their large variety of applications has emerged as an important domain. Among all methodologies Turkevich-Frens synthesis using citrates that act as ligand and reducing agent remains a method of choice for the obtaining of water soluble GNPs. Nevertheless, in post-synthesis, citrates are often exchanged with other ligands to enhanced stabilization and allow further functionalisation. In our work we present a new class of bi-functional molecules (1-hydroxy-1,1-methylene bisphosphonates HMBP) that can both reduce Au(III) and act as an efficient stabilizer of the formed GNPs in water. The first size controlled GNPs “one pot” synthesis was achieved by using an alkene conjugated HMBP, the (1-hydroxy-1-phosphonopent-4-enyl)phosphonic acid (HMBPene). We moreover, rationalized the mechanism of the GNPs synthesis using this type of molecule. We then, evaluated several methodologies for the post-functionalization of our nanoplateform and developed a « Click » chemistry approach to nanoparticle coating by tetrazine cycloaddition. Other nanoplatforms were synthesized using pegylated hydroxyl methylene bisphosphonates. This new class of bisphosphonate coated GNPs showed an improved stability in biological media and brought reactive groups available for post-functionalization as well, illustrated by the coupling of a fluorescent dye. The last part of this was dedicated to our latest results on GNPs synthesis for biomedical applications with HMBP compounds.

Three norbornane fused dihydro-tetrathiafulvalene derivatives which contained the thiol, disulfide and acetylthio functionalities were synthesised. Cyclic voltammetry was used to measure the redox properties of the compounds, which showed that the molecules were able to undergo two reversible, one electron oxidation processes. X-ray structures of all three functionalities were obtained. The three compounds were sublimed onto Au(111) surfaces, and characterised using a number of surface science techniques. Disordered structures are formed initially for all three compounds when adsorbed at room temperature. Following progressive annealing of the substrate, highly ordered adlayer structures are formed that are believed to be bound to the surface via a gold adatom. Van der Waals and hydrogen bonding interactions are shown to play an important role in the formation of these ordered structures. The adsorption of triphenylphosphine sulfide on Au(111) is also investigated, using a combination of RAIRS and STM experiments. Here an extremely ordered (2√3×2√3)R30º structure is formed immediately upon deposition at 298 K. From the experimental data and DFT calculations, the orientation of the molecule is deduced. The attempted synthesis of a thiol functionalised donor-acceptor compound is also described, with a few previously unknown intermediate compounds being synthesised. Finally, a series of four known aryl amidoximes were synthesised. These were subsequently deposited on a Cu(111) crystal and studied using a vibrational spectroscopy. Three of the compounds were found to decompose to varying degrees during the sublimation process. The possible conformations of the amidoxime group on the copper surface are discussed.