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1
Sands, William A., Brittany R. Wurtz, Michael H. Stone, M. R. Brown, J. R. McNeal, and Monem Jemni. "What Is Happening to Olympic Gold Medal Performances?" Digital Commons @ East Tennessee State University, 2007. https://dc.etsu.edu/etsu-works/4497.
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Wong, Pak Mei. "Nationalism behind the coverage of gold medal : a comparative analysis of Olympic reports in Mainland China and Hong Kong newspapers." Thesis, University of Macau, 2006. http://umaclib3.umac.mo/record=b1636345.
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Nash, Casey Aaron. "The Olympic Glory of Jesse Owens: A Contribution to Civil Rights and Society." Digital Commons @ East Tennessee State University, 2012. https://dc.etsu.edu/etd/1510.
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Jesse Owens was the star of the Berlin Olympics in 1936. His four gold medals in Hitler's Germany, as an African American, had far reaching implications back in the United States. Despite segregation and a social hierarchy that was an impasse to both black opportunity and achievement, Owens created a lasting legacy that drastically impacted race relations. The purpose of this thesis was to examine what the Olympic glory of Owens represented for society. Owens as an Olympian in 1936 manufactured a brand of social capital that tied people together in commonality—as Americans. As well, in both myth and deed, Owens has been traditionally credited with challenging Hitler's beliefs of Aryan Supremacy. Yet, Owens was also a race pioneer, as his athletic feats were read in newspapers all over the country, and as a result, helped shift the consciousness of Southerners who were historically ignorant of black achievement.
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Li, Chi-kwan. "Gold(I) and Gold(II) phosphine complexes exhibiting weak AuI ... AuI interactions and unsupported AuII-AuII bonds : syntheses, spectroscopy, host-guest chemistry and reactivity studies /." Hong Kong : University of Hong Kong, 2002. http://sunzi.lib.hku.hk/hkuto/record.jsp?B25155295.
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Khalid, Muhammad. "Gold cyanidation : gold associated with silver minerals embedded within base-metal sulphide matrices." Doctoral thesis, Université Laval, 2017. http://hdl.handle.net/20.500.11794/27893.
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Les problématiques dans le traitement des minerais aurifères deviennent de plus en plus significatives avec la déplétion des gisements à haute teneur autour du monde. L’or est trouvé principalement sous forme métallique dans la nature et est fréquemment associé avec des minéraux d’argent ou des sulfures métalliques. Dans la présente thèse, le rôle des minéraux d’argent sur la cyanuration de l’or au sein de sulfures métalliques est étudié en détail relativement aux interactions galvaniques et aux phénomènes de passivation de surface. Puisque les contacts galvaniques permanents naturellement présents à l’intérieur des grains des minéraux sont difficiles à répliquer en utilisant des montages standards d’électrodes à disques rotatifs ou de la pulpe de minerais riches en sulfures, une stratégie utilisant un réacteur à lit fixe (PBR) a été adoptée afin d’isoler et de quantifier les contributions des interactions galvaniques et des réactions de passivation sur les taux de lixiviation de l’or et de l’argent au sein de sulfures métalliques. Des mélanges d’or, de minéraux d’argent et d’autres sulfures métalliques ont été placés dans le réacteur à lit fixe afin de créer des contacts galvaniques inter-particules permanents parmi les constituants. La pyrite, la sphalérite et la stibnite ont été choisis comme sulfures métalliques modèles. De l’argent métallique (Ag), de l’acanthite Ag₂S) et de la pyrargyrite (Ag₃SbS₃) sont pour leur part les minéraux d’argent qui ont été étudiés. Les interactions galvaniques entre l’or, l’argent et la pyrite ainsi que la sphalérite ont résulté en un comportement complexe de la lixiviation de l’or et de l’argent sous l’impact direct des contacts galvaniques ainsi que sous l’impact des effets de passivation. Les minéraux d’argent ont pour leur part démontré un effet amoindrissant pour la lixiviation de l’or dans de la chalcopyrite et de la stibnite. Des stratégies ont été investiguées pour améliorer la cinétique de lixiviation de l’or en présence de minéraux d’argent et de sulfures métalliques. Des solutions de cyanure contant des sels de plomb ont augmenté la récupération de l’or et ont permis une neutralisation des effets négatifs issus de la présence des sulfures métalliques, particulièrement dans le cas de la chalcopyrite. De plus, l’addition de plomb a augmenté les cinétiques de lixiviation de l’or de manière significative pour l’or et l’argent associé à de la pyrite, de la chalcopyrite et de la sphalérite. Un prétraitement à l’aide d’une solution alcaline d’acétate de plomb a été étudié pour les mêmes couples de minéraux et il a été démontré que cette stratégie augmente la récupération de l’or dans le cas de la pyrite, de la chalcopyrite et de la sphalérite. D’autre part, la stibinite a démontré un effet net de réduction de la dissolution de l’or avec des minéraux d’argent. Des films recouvrant la surface des particules d’or dans le cas de la cyanuration de l’or en présence des sulfures métalliques ont aussi été observés dans le cas de la chalcopyrite et de la stibnite.<br>Numerous non-idealities in gold processing are becoming increasingly significant with the depletion of free-milling oxide ores around the globe. Gold is mostly found in nature in metallic form and is associated with silver minerals and bae-metal sulphides. In the present thesis work, the role of silver minerals on gold cyanidation with base-metal sulphides was elucidated in detail on the relative importance of galvanic interactions and passivation phenomena. As the permanent galvanic contacts, inherently present within the ore grains, are hard to achieve between gold rotating disk electrode and slurried base-metal sulphide-rich ores, a packed-bed reactor (PBR) strategy was thus adopted to single out and quantify the virtual contributions of galvanic interaction and passivation effect on the gold and silver leaching rates during gold cyanidation with silver minerals and base-metal sulphides. The mixtures of gold, silver-minerals and sulphides were filled in the PBR to ensure the permanent particle-particle micro-electrical contacts among all ore constituents. Pyrite, chalcopyrite, sphalerite and stibnite were the sulphidic minerals investigated in the present gold-silver cyanidation study. Metallic silver (Ag), acanthite (Ag₂S) and pyrargyrite (Ag₃SbS₃), were the silver-minerals taken into account. Galvanic interactions were found to alleviate the leaching of gold and silver to various extents, for gold and silver minerals associated with pyrite and sphalerite, both under galvanic and passivation impact from the sulphide minerals. Silver minerals were found retarding to the gold leaching for chalcopyrite and stibnite minerals. Strategies were investigated to enhance the gold leaching kinetics in the presence of silver minerals and base-metal sulphides. Lead containing cyanide solution enhanced gold recovery and was found to neutralize significantly the negative effect of sulphidic minerals, particularly for chalcopyrite. Moreover, lead addition enhanced gold leaching kinetics significantly for gold and silver minerals associated with pyrite, chalcopyrite and sphalerite. Pre-treatment with alkaline lead acetate tested on sulphide associated mixtures of gold and silver minerals affirmed enhanced gold recovery in case of pyrite, chalcopyrite and sphalerite minerals. Stibnite found severely retarding towards gold dissolution with silver minerals. Surface obstructing films were observed on gold particles for gold cyanidation with silver minerals and base-metal sulphides in case of chalcopyrite and stibnite.
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Müller, Ruben S. Ramon. "Homogeneous gold catalysts : development of applications for gold(I) catalysts bearing N-heterocyclic carbene ligands." Thesis, University of St Andrews, 2011. http://hdl.handle.net/10023/2531.
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Recently established as an excellent activator for π-systems, efforts made in gold chemistry have increased enormously, resulting in a new ‘Gold Rush’ in chemistry. This thesis is a small contribution to it. There are two main aspects dominating the following chapters: gold catalysts bearing N-heterocyclic carbenes (NHCs) as supporting ligand, and H₂O assisted catalysis. The initial motivation for the presented work was to specifically demonstrate the potential of [(NHC)AuCl] as suitable catalysts for both known and new organic transformations and to establish these commercially available catalysts in gold chemistry, a field currently dominated by phosphine bearing gold complexes. Water mediated catalysis became the next repeatingly occurring aspect of this thesis by pursuing this initial aim and finding water as a useful solvent or agent, respectively. Various useful applications for gold-NHC complexes are presented, starting with the Meyer-Schuster rearrangement of propargylic alcohols as a continuation of the work realized with propargylic acetates by the Nolan group in early investigations on gold catalysts. Next, a study on alkyne hydration is presented with focus on low catalysts loadings to establish gold catalysts as a powerful choice for such a highly relevant reaction. The catalytic system is then advantageously adapted to a silver-free variation, still active at low catalyst loadings and with further mechanistic insight. Inspired by gold activation of alkynes, a gap of reactivity in gold catalysis is closed by a successful demonstration of nitrile hydration, a functionality previously thought to be inert towards gold activation. In this context, formation and role of dinuclear hydroxy-bridged gold complexes is investigated highlighting these complexes as a possible resting state of gold complexes in the presence of water. Next, the formation of furanones via alkoxylation/lactonization of propargylic propiolates is presented, an observation initially made when exploring the scope of the Meyer-Schuster rearrangement. The dissertation finally closes with the gold-catalyzed formation of amides, this time however achieved from aldoximes reacting via dehydration/hydration mechanism.
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Li, Chi-kwan, and 李志君. "Gold(I) and Gold(II) phosphine complexes exhibiting weak AuI... AuI interactions and unsupported AuII-AuII bonds: syntheses, spectroscopy, host-guest chemistry and reactivity studies." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2002. http://hub.hku.hk/bib/B31243332.
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Choi, Wing-kin Sam. "Synthesis, photophysics and photochemistry of mono- and polynuclear complexes of gold /." Hong Kong : University of Hong Kong, 1995. http://sunzi.lib.hku.hk/hkuto/record.jsp?B17591168.
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Fraser, Adam Earl. "Synthesis and characterisation of gold- and platinum-based multimetallic catalysts." Thesis, University of Cambridge, 2016. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.709517.
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Raymond, Luke M. "Gold and Base Metal Mineralization of the Dolphin Intrusion-related Gold Deposit, Fairbanks Mining District, Alaska." Thesis, University of Alaska Fairbanks, 2018. http://pqdtopen.proquest.com/#viewpdf?dispub=10929098.
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<p> The Dolphin deposit is an intrusion-related gold deposit (IRGD) located approximately 30 km north of Fairbanks, Alaska. The deposit is in--and adjacent to--a composite mid-Cretaceous pluton intruding amphibolite facies metamorphic rocks. NI43-101 compliant gold resource estimations for the deposit utilizing a 0.3 g/t cut-off, is 61.5 Million tonnes (Mt) at 0.69 g/t indicated (1.36 million oz = Moz) and 71.5 Mt at 0.69 g/t inferred (1.58 Moz). </p><p> Due to extensive hydrothermal alteration of the intrusion, identifying lithology in hand sample and thin section, as well as by standard compositional techniques (SiO<sub>2</sub> vs. Na<sub>2</sub>O + K<sub>2</sub>O), has proven problematic. By plotting wt% TiO<sub>2</sub> vs. P<sub>2</sub>O<sub>5</sub> obtained from XRF analysis and four-acid digest ICP-MS data, two distinct population clusters appear. By comparison with least-altered intrusive rock analyses from the Fairbanks district, the igneous units can be identified as granite and tonalite. Because there is no gradational transition through an intermediate granodiorite unit, they were most likely derived from two separate magmatic bodies rather than <i>in-situ</i> fractionation from a single parent. Tonalite is concentrated along the northern and eastern margins of the stock with granite composing the rest of the body. Tonalite xenoliths in granite and granite dikes intruding tonalite prove that tonalite is the older unit. </p><p> Investigations of hydrothermal alteration (based on chemical analyses, X-ray diffraction, and thin section examination) show albitic and advanced argillic (kaolinite-quartz) alteration are the dominant styles with sericite common throughout. Advanced argillic is a low temperature (<300°C) low pH alteration style that has not been previously identified in intrusion related gold deposits (IRGDs) in interior Alaska. Albitic alteration resulted from higher temperature, more neutral pH fluids. </p><p> Gold investigations show that gold occurs as coarse-grained Au°, aurostibite, and maldonite in quartz + sulfide veins; fine-grained Au° in the oxide zone; and in many forms in disseminated sulfide. These forms include Au° inclusions in pyrite and arsenopyrite, solid-solution Au within compositionally zoned arsenopyrite, and as Au° nanoparticles in pyrite and arsenopyrite. Using UAF’s JEOL JXA-8530F microprobe, I found that solid-solution gold occurs only in arsenopyrite with strong compositional zoning. These have low As cores; gold-bearing mantles with moderate % As; and high As rims. In contrast, compositionally homogenous arsenopyrite does not contain solid-solution gold. Pyrite is commonly arsenian and carries dissolved gold (if any) near detection limits. Gold mineralization has not been tied to any lithology or alteration style; however, gold does seem to correlate with abrupt changes in alteration, especially between sericite + albite and kaolinite + sericite alteration and gold-bearing, zoned arsenopyrites are associated with advanced argillic alteration.</p><p>
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Marsh, Patrica Ann. "Metal complexes as precursors for film deposition processes." Thesis, Open University, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.262973.
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Robinson, Matthew Peter. "Ortho-substituted arylsilanes in oxidative gold catalysis." Thesis, University of Edinburgh, 2018. http://hdl.handle.net/1842/31394.
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Organometallic compounds derived from tin, boron, and zinc, have been used extensively in transition metal-catalysed cross-coupling, and continue to hold status as the go-to reagents to form new carbon-carbon bonds. Recently, organosilicon compounds have emerged as an attractive alternative to these established reagents, benefitting from low toxicity, low cost, and general ease of handling. While the fundamental reactivity of arylsilane reagents (Ar-SiR3) is well known, their role in transition metal-catalysed reactions is generally less well studied. This thesis comprises an investigation into the effect of ortho-substitution of these arylsilane reagents, and specifically, their application in gold-catalysed direct arylation. In Chapter 2, the transmetalation of these reagents to gold(III) is assessed using a combination of in situ reaction monitoring coupled with kinetic simulations. This allowed a scale of reactivity to be constructed for a range of structurally diverse arylsilanes, and uncovered that more sterically hindered arylsilanes actually exhibit accelerated rates of transmetalation. In Chapter 3, the reactivity of ortho-substituted arylsilanes in gold-catalysed arylation is addressed. The majority of arylsilanes tested in the previous chapter were found to be unable to undergo coupling, despite the viability of transmetalation having been demonstrated. Slight modification of the ortho-substituent, to incorporate a tethered ligand, was found to have a dramatic effect on reactivity, and allowed the coupling of a variety of substrates. The nature of the ligand, as well as the substitution of the tether was found to have a significant impact on the rate of coupling. Chapter 4 describes the way in which the reactivity of ortho-substituted arylsilanes might be exploited in a 'Catch and Release' protocol for catalyst recovery. This aims to combine the established benefits of homogeneous and heterogeneous catalysis to offer an alternative to current methods of catalyst recycling in industrial chemistry. A number of different 'Catch and Release' mechanisms were considered, and the validity of the concept was demonstrated in a monophasic system.
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Garcia, Marisol. "TRULY NON INVASIVE GLUCOSE OPTICAL SENSOR BASED ON METAL NANOPARTICLES GENERATION." Master's thesis, University of Central Florida, 2006. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/2260.
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Diabetes is a disease that causes many complications in human normal function. This disease represents the sixth-leading cause of death in USA. Prevention of diabetes-related complications can be accomplished through tight control of glucose levels in blood. In the last decades many different glucose sensors have been developed, however, none of them are really non invasive. Herein, we present the study of the application of gold and silver nanoparticles with different shapes and aspect ratios to detect glucose traces in human fluids such as tears and sweat. This is to our knowledge the first truly non invasive glucose optical sensor, with extraordinary limit of detection and selectivity. The best proven nanoparticles for this application were gold nanospheres. Gold nanospheres were synthesized using chloroauric acid tri-hydrated (HAuCl4.3H2O) in solution, in the presence of glucose and ammonia hydroxide. The higher the glucose concentration, the higher the number of nanoparticles generated, thus the higher the extinction efficiency of the solution. The linear dependence of the extinction efficiency of the gold nanoparticles solution with glucose concentration makes of this new sensor suitable for direct applications in biomedical sensing. Our approach is based on the well known Tollens test.<br>M.S.<br>Department of Chemistry<br>Arts and Sciences<br>Industrial Chemistry
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Donoeva, Baira. "Study of catalytic and biological activity of gold-containing metal nanoparticles." Thesis, University of Canterbury. Chemistry, 2014. http://hdl.handle.net/10092/9761.
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Small particles of gold (< 100 nm) have attracted great interest among researchers due to the unique combination of their physicochemical properties. Among various research areas catalysis and bio-nanotechnology represent the largest areas of growth for gold nanoparticle research.
Catalysts play a crucial role in the life of the modern society. More than 85 % of all chemical processes are catalytic, and this number is increasing every year. There is a constant demand to develop more efficient and durable catalysts in order to address increasing energy demands and environmental requirements. The first part of the thesis is focused on the study of catalytic activity of supported gold and mixed-metal catalysts, derived from atomically precise phosphine-stabilised gold and mixed-metal clusters in the liquid-phase oxidation of cyclohexene and one-pot synthesis of imines. Various characterisation techniques (TEM, diffuse-reflectance UV-vis, XPS, etc.) as well as kinetic studies were used in order to establish the optimal structure of gold catalysts. The effect of catalytic support, nature of hetero-metal atom for mixed metal-systems and type of catalyst pre-treatment were also examined.
Gold nanoparticles are actively studied in various biomedical applications as they are offering new approaches to the detection and treatment of life-threatening diseases, such as cancer. The second part of this work discusses our preliminary investigations of biological activity of gold nanoparticles, stabilised with cancer-targeting molecules. In particular, the cytotoxicity of gold nanoparticles was studied using 11 different cancer and normal cell types. Gold uptake and particle localisation inside the cells were also investigated.
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Moran, John Thomas. "The electronic structure of gold-induced reconstructions on vicinal silicon(111)." Thesis, University of Liverpool, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.283057.
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Getton, Frederick P. "Design of metal oxide catalysts." Thesis, Brunel University, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.314049.
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Wilson, Nicholas Thomas. "The structure and dynamics of noble metal clusters." Thesis, University of Birmingham, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.368419.
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Murrell-Mottram empirical atomistic many-body and Gupta n-body potentials have been used to study various aspects of the cluster chemistry of copper, silver, gold and nickel. Simulated annealing techniques have been used to search for the global minima of the four metals with up to 55 atoms. Icosahedral, decahedral, octahedral, hexagonal closed packed and hexagonal prismatic structures were found. The gold clusters show some rearrangements and distortions from ideal geometries. Polyhedral cluster calculations up to 1 500 atoms predict that icosahedra and truncated octahedra are particularly stable. Calculations on the structures of copper-gold alloy clusters show that gold atoms prefer to occupy the surface of the cluster. A simple approximation to model the passivation of gold clusters by thiol ligands predicts that for 55 atoms the passivated cuboctahedron is more stable than the icosahedron, the reverse of the order for the bare clusters. Molecular dynamics simulations of gold adatoms on the gold (111) surface and of the impact of a 55 atom gold cluster with the gold (111) surface have been performed.
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Al-Dabbagh, J. B. "Some properties of thin metal films in reacting and non-reacting substrates." Thesis, University of Reading, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.234487.
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Calatayud, Sanz Maria Pilar. "Self-assembled monolayers of metal complexes attached to gold electrodes." Thesis, University of Edinburgh, 2009. http://hdl.handle.net/1842/10851.
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In this thesis, ten different ligands were designed and synthesized in such a way as to provide metal containing SAMs. The metal binding sites of these ligands are derivatives of the tripodal ligand tris(2-pyridylmethyl)amine (TPA) and the tridentate amine bis(2-pyridylmethyl)amine (BPA), which have good molecular recognition properties in solution. As interface separating the electrode from the metal binding site and gold anchor group we have chosen a thiophenyl, thioethyl and thioctic acid groups. Electrochemical studies with [Fe(CN)<sub>6</sub>]<sup>3-/4-</sup> as redox probe in solution were carried out on SAMs of the TPA thioctic acid derivative L4 and its complexes Cu-L4, Zn-L4 and Fe-L4. Monolayers containing redox active Cu(II/I) ions accelerated the electron-transfer reaction (<i>k</i><sub>app </sub>= 2.78 x 10<sup>-2</sup> cm/s) more than those containing Zn(II) (<i>k</i><sub>app</sub> = 1.51 x 10<sup>-4</sup> cm/s) and Fe(II) (<i>k</i><sub>app </sub>= 1.40 x 10<sup>-3</sup> cm/s) ions. This is consistent with a mechanism for electron-transfer in which the Cu ions exit in different coordination environments and with different redox potentials, and are rapidly undergoing interconversion. The ability of this system to facilitate the electron-transfer process to the redox probe was used to develop a new cyanide sensor. Addition of cyanide ions increases the blocking behaviour of the SAM, suggesting the elimination of Cu from the SAM to form [Cu(CN)<sub>n</sub>]<sup>(n-1)- </sup>complexes. The cyanide detection limit was found to be 1 nM. Electrodes modified with the binucleating ligand 2,6-bis[bis(2-pyridylmethyl)amino-methyl]phenol thioctic acid derivative (bearing two BPA arms) L7 were also investigated. Metal containing SAMs can influence the electron-transfer process through the SAM to a solution containing a redox probe. This property can be used to develop new anion sensors in aqueous system.
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Gendall, Ian Richard. "The porphyry copper system and the precious metal-gold potential." Thesis, Rhodes University, 1994. http://hdl.handle.net/10962/d1005604.
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It has been established that porphyry copper/copper-gold deposits have formed from I Ma to 2 Ga ago. Generally, they are related to the Mesozoic-Cenozoic interval with few reported occurrences from the Palaeozoic or Precambrian. A reason cited is the erosion of these deposits which are often related to convergent plate margins and orogenic belts. Observations of the alteration and mineralisation within and around porphyry copper/copper-gold systems have been included in numerous idealised models. These alteration and mineralisation patterns are dependent on the phases of intrusion, the tectonic setting and rock type, depth of emplacement and relationship to coeval volcanics, physiochemical conditions operative within and surrounding the intrusive and many other mechanical and geochemical conditions. Island arc and cratonic arc/margin deposits are generally considered to be richer in gold than their molybdenum-rich, intra-cratonic counterparts. Metal zonation may occur around these copper/copper-gold deposits, e.g. copper in the core moving out to silver, lead, zinc and gold. This zonation is not always present and gold may occur in the core, intermediate or distal zones. Examples of gold-rich porphyry deposits from British Columbia, Chile and the SW Pacific Island regions suggest gold is closely associated with the potassic-rich zones. Generally these gold-rich zones have greater than 2% magnetite and a high oxygen fugacity is considered to be an important control for gold deposition. High Cl contents within the magma are necessary for gold mobility within the host intrusive centres. Beyond this zone HS₂ becomes an important transporting ligand. Exploration for porphyry copper-gold deposits includes an integrated geological, geophysical and geochemical approach. Petrographic work through to Landsat imagery may be used to determine the chemical conditions of the system, ore association, favourable structural zones and alteration patterns, in order to focus exploration activities.
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Aksoy, Fuat Yigit. "Interaction of Metal Nanoparticles with Fluorophores and Their Effect on Fluorescence." Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2009. http://nbn-resolving.de/urn:nbn:de:bsz:14-ds-1240302257150-32578.
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Metal nanoparticles have recently gained popularity in many research areas due to their nanosize-related properties. Depending on the size of the metal nanoparticle, their mode of interaction with electromagnetic radiation and the outcome of this interaction vary; in turn the effect exerted on a protein which is conjugated to a nanoparticle varies, because different sized nanoparticles demonstrate different modes of energy transfer with electromagnetic radiation and molecules conjugated to them. Very small cluster with sizes around 1 – 1.2 nm tend to get excited by incident light and emit fluorescence, whereas larger nanoparticles absorb the incoming light very strongly due to their LSPR. In this study we observed the outcomes of the interaction between two types of nanoparticles, namely gold and gold/silver alloyed nanoparticles with the fluorescence emission of two fluorophores, namely eGFP and rPhiYFP; and demonstrated a bioassay where the fluorescence modulation by gold nanoparticles can be used as the sensing strategy. Lastly, we demonstrated the potential of autofluorescent gold nanoparticles as intracellular reporters.
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Hastings, Matthew H. "Relationship of base-metal skarn mineralization to Carlin-type gold mineralization at the Archimedes gold deposit, Eureka, Nevada." abstract and full text PDF (UNR users only), 2008. http://0-gateway.proquest.com.innopac.library.unr.edu/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:1460760.
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Robinson, Donald A. III. "Synthesis and Characterization of Metal Nanoclusters Stabilized by Dithiolates." Digital Archive @ GSU, 2011. http://digitalarchive.gsu.edu/chemistry_theses/44.
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Rapidly expanding research in nanotechnology has led to exciting progress in a versatile array of applications from medical diagnostics to photocatalytic fuel cells. Such success is due to the ability of researchers to manipulate the desired properties of nanomaterials by controlling their size, shape, and composition. Among the most thriving areas of nanoparticle research has been the synthesis and characterization of stable metallic nanoclusters capped by thiolate ligands. Our group has extended this research to study copper, silver, and gold clusters with remarkable stability and energetics, which was achieved by using dithiolates as the ligand stabilizers. In addition to the enhanced stability offered by the chelate effect, the use of dithiolate ligands instead of monothiolates is proposed to provide an alternate interfacial bond structure that is shown to strongly influence energetic properties of nanoclusters, with strong evidence of metal-ligand charge transfer. Energetic properties were characterized by spectroscopic and electrochemical methods.
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蔡永健 and Wing-kin Sam Choi. "Synthesis, photophysics and photochemistry of mono- and polynuclear complexes of gold." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 1995. http://hub.hku.hk/bib/B31234781.
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Matsuoka, Tomoyo. "Controlled assembly of metal nanostructures and their application to sensitive molecular sensing." 京都大学 (Kyoto University), 2013. http://hdl.handle.net/2433/174949.
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Humphrey, Paul Andrew. "A study of transition metal complexes /." Title page, contents and summary only, 1990. http://web4.library.adelaide.edu.au/theses/09PH/09phh9262.pdf.
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Zheng, Yiqun. "Seeded growth of noble metal nanocrystals." Diss., Georgia Institute of Technology, 2013. http://hdl.handle.net/1853/50315.
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This research emphasizes on the use of seeded growth in synthesis of noble metal nanocrystals with precise control over the size, shape, and composition.
In the first part of this work, I have produced Au nanocrystals with single-crystal structure and truly spherical profiles and investigated their optical properties and self-assembly as induced by dilution with water. These Au nanospheres were generated in high yield and purity, together with controllable sizes continually increased from 5 to 150 nm. I also found these Au nanospheres self-assembled into dimers, larger aggregates, and wavy nanowires, respectively, as diluted with water.
In the second part of this work, I demonstrate the kinetic control can be implemented to control the shape of mono- and bi-metallic nanocrystals in seeded growth. The as-prepared single-crystal nanospheres of Au were employed as seeds to synthesize of tetrahedral Au nanocrystals and Au@Pd core-shell nanocrystals with six distinct shapes. The success of the two demonstrations relies on manipulation of reaction kinetics to achieve different product shapes. The reaction kinetics was controlled by varying a set of reaction parameters, including the type and concentration of capping agent, the amount of reductant, and the injection rate of metal precursor solution.
In the final part of this work, I will discuss an unusual change in crystallinity observed in seeded growth of Au nanocrystals on Au seeds. In particular, single-crystal Au seeds treated with a chemical species could develop twin defects during the seed-mediated growth process to yield multiply twinned products.
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Gabrysiak, Diane. "The representation of money in film : gold, paper, metal and electronic." Thesis, University of Warwick, 2006. http://wrap.warwick.ac.uk/48978/.
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This dissertation is a study of the representation of money on screen, in its textual and contextual constructions. Money, itself a representation, has a complex status: it is both an abstract concept, a symbol of value, a social convention, and a concrete object in its embodiment as gold, metal or paper. This study then is that of a representation of a representation. Its starting point is the very paradox of money as both an object endowed with great value while at the same time not worth much more than the substance it is made of or the numbers referring to it in newer forms of electronic money. The paradox is particularly salient in a medium that works through images while at the same time requiring itself so much money. The distinction between the two Latin words moneta and pecunia offers an understanding of money in its main properties and functions, as an exchange tool in constant circulation and as an object of hoarding, as belongings. This distinction is operative in the present study and runs through the thesis, together with the Marxian concepts of use-value and exchange value. The objective is to analyse patterns, peculiarities and meanings linked to the portrayal of money. This thesis does not encompass a comprehensive survey of money represented in all of cinema. Instead, the study is conducted in four groupings of films that are not necessarily thought of in connection with their images of money. Four chapters examine films from different contexts, periods, genres or trends in the cinema of various countries. The groupings are suggested partly by issues outside of money and partly by periods and kinds of money, and focus on case studies while simultaneously referring to a larger corpus. The first chapter examines the issues raised by the topic and surveys the existing literature. The second chapter undertakes an analysis of gold and gold mining in the context of the pioneering West in US films. The third chapter considers paper money and its meanings in neo-realist films. The thesis then proceeds to study films from the 1970s and 1980s. The fourth chapter concerns money in French films on high finance, and the last chapter looks at money as it appears in horror films. The thesis ends with a discussion of the recurrent patterns at work in the representation of money.
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Best, Sabine Lieselotte. "Metal recognition by peptides : relationship to the immunochemistry of gold drugs." Thesis, Birkbeck (University of London), 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.244264.
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Desai, Darshan B. "Metal Enhanced Fluorescence in CdSe Quantum Dots by Gold Thin Films." Ohio University / OhioLINK, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1314234319.
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Soreta, Tesfaye Refera. "Electrochemically deposited metal nanostructures for application in genosensors." Doctoral thesis, Universitat Rovira i Virgili, 2009. http://hdl.handle.net/10803/8579.
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Las señales de los biosensores se pueden mejorar mediante el diseño de superficies transductoras. En este sentido, se han investigado diversos métodos para la nanoestructuración de superficies. El primero de ellos se basó en la formación inicial de monocapas autoensambladas (SAM) de alcanotioles sobre sustratos bimetálicos, seguida de la desorción reductiva selectiva (SRD) de las SAM de determinados metales. Se consiguió la SRD de 2-mercaptoetanol de dominios de paladio desde una superficie de platino-oro. El segundo método para preparar superficies nanoestructuradas que se investigó fue la nucleación electroquímica secuencial de las nanopartículas metálicas (oro y paladio) sobre electrodos de carbón vidrio para las SAM de alcanotiol y para aumentar la densidad de las nanopartículas sin permitir la formación de agregados. Con este método, las señales redox de las SAM alcanotiol ferrocenil eran seis y cincuenta veces mejores que los electrodos de oro y paladio, respectivamente. Finalmente, se demostró la nanoestructuración de las superficies de los electrodos para mejorar la señal de un biosensor de ADN.<br>Biosensor signals can be enhanced by specifically designing transducer surfaces. In this thesis, several surface nanostructuring approaches have been investigated. The first approach studied was based on the initial formation of self-assembled monolayers (SAM) of alkanethiols on bi-metallic substrates, followed by the selective reductive desorption (SRD) of the SAM from one of the metals. SRD of 2-mercaptoethanol from palladium domains of a palladium-gold surface was achieved. The second nanostructured surface preparation method investigated was the sequential electrochemical nucleation of metal nanoparticles (gold and palladium) on glassy carbon electrode and SAM formation on the NPs to prevent aggregation and by that increasing the number densities. With this method, a six-fold and a fifty fold enhancement in the ferrocenyl alkanethiol SAM redox signal was achieved in comparison to plain gold and palladium electrodes, respectively. Finally, electrode surface nanostructuring using sequentially nucleated gold nanoparticles for signal enhancement of DNA biosensor was demonstrated.
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Attard, G. A. "The structure and reactivity of copper, silver and gold overlayers on W(100)." Thesis, University of Liverpool, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.382046.
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Benton, Erin Nicole. "Development and Testing of Gold(I) and Europium(III) Based Sensors for Environmental Applications." Thesis, University of North Texas, 2019. https://digital.library.unt.edu/ark:/67531/metadc1505138/.
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This dissertation focuses on the development, characterization, and analysis of luminescent materials and coatings for sensing applications, including CO2, heavy metals, and silver. Chapter 2 involves the use of a gold(I) pyrazolate trimer that is able to detect silver ions with an AgNP medium. Detection of silver is vital, because there is an influx of silver into our environment caused by the increased use of AgNP. Therefore, having a sensor that is able to differentiate between and detect only Ag ions is an important first step to solving the toxicity mystery of AgNPs. Chapter 3 focuses on the development of sensor coatings containing a Eu(III) based luminescent system for sensing dissolved CO2 without the aid of an absorption-based dye. It is well-known that monitoring CO2 levels in our environment is important since even at low concentrations it can cause adverse health effects to the human body. This work demonstrates a pH-sensitive Eu complex being used directly as a CO2 sensor without the aid of any other absorption-based dye. Chapter 4 explores the idea of developing a heavy metal sensor for lead and its ability to detect lead in wide concentration range upon changing the pH of the medium and the polymer matrix. Different heavy metals have toxicity at different concentrations, therefore, being able to change the dynamic range of the sensor is advantageous. This research is the first step towards developing a luminescent Pb sensor with a tunable dynamic range.
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Mukhopadhyay, Rupa. "Scanning probe microscopy of functionalised metal surfaces." Thesis, University of Oxford, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.343521.
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Dill, Kathryn Ann. "Process Optimization for the Synthesis of Gold Nanoparticles from a Mixed Metal Precursor Solution." VCU Scholars Compass, 2018. https://scholarscompass.vcu.edu/etd/5326.
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Separation methods involving a mixture of metals typically include upfront processing that leads to one final product. To lower the waste and ultimately environmental burden, the potential to synthesize multiple functional products from a mixed metal precursor solution is explored. The initial precursor solutions contained varying ratios of gold and copper, gold and nickel, and finally a ternary solution of gold, copper, and nickel. The amount of gold was kept constant, while the amount of copper and/or nickel was sequentially increased. Two separate synthesis processes were tested, the traditional Turkevich method involving trisodium citrate and another chemical reduction method involving sodium borohydride. The particle size and chemical composition of the synthesized particles were characterized using TEM, DLS and ICP-OES. It was determined that gold nanoparticles still formed at a ratio of 1 to 2 gold to copper while using trisodium citrate or sodium borohydride as the reducing agent. The same limiting ratio was observed for the gold to nickel reactions in the presence of either trisodium citrate or sodium borohydride. The ternary mixture limit for gold nanoparticle formation was a molar ratio of 1 to 1 to 1 gold to copper to nickel. The repeatability and stability results for the optimized binary reaction conditions indicate that using sodium borohydride as the reducing agent consistently produces more stable particle suspensions. Quantifying the environmental impact using green chemistry metrics indicate the Turkevich reactions for the optimized reactions have the lower environmental factors.
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Yan, Kun. "Proteomic and biochemical studies of cytotoxic gold(I), silver(I) and rhodium(II) complexes." Click to view the E-thesis via HKUTO, 2007. http://sunzi.lib.hku.hk/hkuto/record/B3963436X.
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Coventry, David N. "Tertiary-phosphine gold(I) and copper(I) complexes : precursors for metal deposition." Thesis, University of Edinburgh, 2002. http://hdl.handle.net/1842/12017.
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Tertiary-phosphine stabilised gold and copper complexes have been prepared with the intention to deposit elemental metal from solution. These complexes were intended to be delivered as a component of an ink on to a suitable substrate by an ink-jet printing process. Testing the compatibility of these complexes with ink-jet technology has been undertaken by Avecia and Seiko-Epson (this project's industrial sponsors). Four methyl(tertiary-phosphine)gold(I) complexes with a general molecular formula, [R<sub>3</sub>PAuCH<sub>3</sub>] (R = Ph, Ph-<i>p</i>-F, Ph-<i>p</i>-OMe and Me) were prepared by reacting (tertiary-phosphine)gold(I) chloride with methyllithium. Toluene-d<sub>8</sub> and decalin solutions of these complexes were heated to 100°C and the rate of decomposition of each complex to gold(O), tertiary-phosphine and ethane was measured spectroscopically by NMR and GC respectively. Relatively the gold(I) complexes were found to decompose in the following order: Ph-p-F > Ph > Me >> Ph-p-OMe A series of tertiary-phosphine stabilised copper(I) aryloxide complexes, with the general molecular formula [{(RO)Cu(PR'<sub>3</sub>)<sub>m</sub>}<sub>n</sub>], were synthesised with the intent to duplicate the results obtained for the gold(I) complexes with a copper system. All the copper(I) complexes prepared were found to be too thermally stable to be suitable for the aim of the project. During the course of this project it was noted that the steric and electronic factors involved in producing the thermodynamic product from the reaction mixture were of major importance in the design of such complexes. Increase in overall steric bulk was, as expected, found to lead to copper(I) ions with lower coordination numbers while an increase in the electron affinity of the ligands was found to produce complexes with copper ions with higher coordination numbers.
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Priest, Joshua Duncan. "Investigating the reactivity of a-oxo gold metal carbenoids formed from ynamides." Thesis, University of Birmingham, 2017. http://etheses.bham.ac.uk//id/eprint/7987/.
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The work presented in this thesis focusses upon the use of α-oxo gold carbene species formed from the intermolecular oxidation of ynamides, and their application as alternatives to diazo compounds in carbene chemistry. Throughout this work the use of ynamides has allowed production of α-oxo gold carbene species that would be either unobtainable or difficult to produce through dediazotisation chemistry. Allowing for the synthesis of novel compounds while avoiding the impractical or hazardous chemistry that would be necessary to produce the equivalent diazo compounds. The use of α-oxo gold carbenes in the synthesis of novel compounds in intramolecular Buchner reactions, the initial difficulties encountered and investigation of how carbene character and substrate choice affects the product selectivity observed in these reactions is described. Examination of the [2,3]-sigmatropic rearrangements of sulfonium ylides, formed from gold catalysed ynamide oxidation, and the effects of ynamide and sulfide variation upon the atypically high diastereoselectivity observed are described and discussed. A range of novel products has been produced and efforts towards their derivatisation described.
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Du, Yuchen. "Modelling and Forecasting Volatility of Gold Price with Other Precious Metals Prices by Univariate GARCH Models." Thesis, Uppsala universitet, Statistiska institutionen, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-187914.
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This paper aims to model and forecast the volatility of gold price with the help of other precious metals. The data applied for application part in the article involves three financial time series which are gold, silver and platinum daily spot prices. The volatility is modeled by univariate Generalized Autoregressive Conditional Heteroskedasticity (GARCH) models including GARCH and EGARCH with different distributions such as normal distribution and student-t distribution. At the same time, comparisons of estimation and forecasting the volatility between GARCH family models have been done.
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Ruch, Aaron A. "Design of New Monodentate Ligands for Regioselectivity and Enantioselectivity Tuning in Late Transition Metal Catalysis." Thesis, University of North Texas, 2016. https://digital.library.unt.edu/ark:/67531/metadc849723/.
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The ability of gold(I) to activate many types of unsaturated bonds toward nucleophilic attack was not widely recognized until the early 2000s. One major challenge in gold catalysis is the control over regioselectivity when there are two or more possible products as a result of complicated mechanistic pathways. It is well know that the choice of ligand can have dramatic effects on which pathway is being followed but very rarely are the reasons for this selectivity understood. The synthesis of new acyclic diaminocarbenes was developed and a study of the ligand effects on the regioselectivity of a gold-catalyzed domino enyne cyclization hydroarylation reaction and a Nazarov cyclization was undertaken. New chiral acyclic diaminocarbenes were also developed and tested along side new C3-symmetric phosphite ligands in an asymmetric intramolecular hydroamination of allenes. Structure activity correlations were developed for the potential use in further rational ligand design. The synthesis of 6a,7-dihydro-5-amino-dibenzo[c,g]chromene derivatives via a gold-catalyzed domino reaction of alkynylbenzaldehydes in the presence of secondary amines was developed. These were sent to be screened for biological activity.
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Nikitin, Andrey. "Collective plasmon resonances in diffractive arrays of gold nanoparticules." Thesis, Aix-Marseille, 2013. http://www.theses.fr/2013AIXM4035.
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Dans ce travail, les propriétés des réseaux diffractifs ordonnés de nanoparticules d'or sont étudiées numériquement et expérimentalement. Ces résonances sont beaucoup plus étroites que celles observées dans le cas d'une nanoparticule isolée. D'après les simulations numériques, deux régimes distincts de réponse sont identifiés, l'un correspond à l'anomalie de Rayleigh (RA) l'autre au mode plasmon de réseau 2D (LPM). Dans la partie expérimentale nous avons fabriqué des réseaux de nanoparticules d'or en utilisant la lithographie d'électronique. La transmission spectrale a été mesurée dans le domaine optique pour caractériser ces réseaux. Toutes les caractéristiques essentielles des spectres expérimentaux sont en bon accord avec les simulations numériques. Les distributions du champ électrique pour différents paramètres de réseau sont étudiées pour obtenir le maximum d'augmentation du champ à la surface de la nanoparticule. L'excitation des résonances plasmon dans les réseaux diffractifs de nanoparticules d'or en condition asymétrique de l'indice de réfraction est examinée expérimentalement. L'excitation des modes plasmon à profil spectral étroit dans l'environnement asymétrique a été expérimentalement vérifiée. La possibilité d'accorder la longueur d'onde de ces résonances dans le proche infrarouge en changeant les paramètres structurels des réseaux périodiques en combinant taille et forme des nanoparticules est discutée. Ces résultats sont importants pour les applications telles que les spectroscopies en champ électrique exalté et la détection en biologie ou en chimie<br>The properties of ordered diffractive arrays of gold nanoparticles are studied numerically and experimentally. Using numerical simulations I identify, two distinct regimes of lattice response, associated with two-characteristic states of the spectra: Rayleigh anomaly and lattice plasmon mode. In experimental part gold nanoparticle arrays were fabricated using e-beam lithography. Spectroscopic transmission measurements then were carried out to optically characterize these arrays. All the essential features of the experimental spectra were reproduced well by numerical simulations. Electric field distributions for different lattice parameters are studied in order to maximize the enhancement of electric field at the nanoparticle surface. The excitation of plasmon resonances in diffractive arrays of gold nanoparticles placed in asymmetric refractive index environment is examined experimentally. The excitation of the plasmon modes with narrow spectral profile in asymmetric environment was experimentally verified. The ability to tune the wavelength of these resonances in the near infrared range by varying the structural parameters of the periodic arrays in combination with size and geometry of the constituent nanoparticles is discussed. The presented results are of importance for the field enhanced spectroscopy as well as for plasmonic bio and chemical sensing
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Jonke, Alex P. "Atomic metal/polyaniline composites." Diss., Georgia Institute of Technology, 2013. http://hdl.handle.net/1853/49070.
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It is ideal to theoretically predict the activity of a catalyst. It has been recognized that not only the type of metal, but also its atomic size plays an important role in catalysis. In the past, atomic clusters have been created by sputtering from a sacrificial metal plate and then using a mass selector to choose cluster sizes from 1-233 atoms of gold. This approach has practical limitations. In this thesis, I describe a procedure by which atomic clusters of gold containing 1-8 atoms are deposited in polyaniline as an isolation matrix. My atomic deposition follows a cyclic pathway. Atomic clusters of palladium and atomic alloys of gold and palladium are also deposited in polyaniline using the same process. It is to show that this method will also work for other metals. These composite materials are characterized, and the catalytic activity for alcohol oxidation is evaluated.
This thesis is divided into seven chapters. The first chapter discusses the chemistry of polyaniline for using gold and palladium as catalysts. The technique developed to deposit the atomic clusters is discussed in the second chapter. This technique deposits one atom of metal per imine site on polyaniline, per cycle. The cycle is repeated n-times until a cluster of specified size, Mn, and composition has been synthesized. It is known that polyaniline plays an important role in stabilization of the formed clusters which prevents their aggregation. The optimization of this technique is the topic of the third chapter along with the description of how these composite films are produced. To end this chapter, the composite films are characterized by cyclic voltammetry, Kelvin probe, and X-ray photoelectron spectroscopy.
In chapters 4 and 5, the catalytic activity of the polyaniline/gold composites for the oxidation of alcohols in alkaline media using cyclic voltammetry is evaluated. In chapter 4, the correlation of the electrochemical activity for the oxidation of n-PrOH with the odd-even pattern from the calculated HOMO-LUMO gap energies for the same size clusters is shown. It is shown that the infrared spectrum of polyaniline with different sizes of atomic gold clusters also follows the odd-even pattern. Chapter 5 expands on the discussion of the catalytic oxidation of alcohols. The oxidation of methanol, ethanol, propanol, and butanol is surveyed. The peak currents are again dominated by the odd-even pattern.
In chapter 6, the versatility of the atomic deposition cycle is shown by depositing atomic palladium clusters. The peak currents for the oxidation of n-PrOH by these palladium composite films again follows the predicted pattern of the calculated HOMO-LUMO gap energies for atomic palladium clusters. This chapter also explores bimetallic atomic clusters of gold and palladium. The results indicate that the catalytic activity depends on the orientation of the cluster in the polyaniline matrix. Chapter 7 discusses the oxidation of methanol, ethanol, and isopropanol on AunPd1 bimetallic atomic clusters. The addition of palladium in the cluster increases the peak current densities for the oxidation of both alcohols except for the most stable of the atomic gold clusters, while it inactivated the electrodes for isopropanol. The possible future work for this project is discussed in chapter 8.
Overall, this thesis has developed a novel and unique technique for depositing atomic metal clusters into a polyaniline matrix. The technique is versatile enough to deposit atomic metal clusters other than gold, as shown by creating atomic palladium clusters and atomic bimetallic clusters of gold and palladium. This is extremely useful, since this single technique can produce many different types of atomic catalysts. The composite materials have been shown to be catalytically active for the oxidation of alcohols in alkaline media. This indicates a significant improvement to conserve precious metals while still retaining a high catalytic activity.
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Ziegler, Christoph. "Syntheses and Assemblies of Noble Metal Nanostructures." Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2013. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-101781.
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Shape and size control as well as the control of the assembly of nanostructures are current challenges in nano sciences. Focussing on metal nanostructures all of these aspects have been addressed in the frame of the present work. It was possible to develop a new aqueous seeded growth method that produces gold nanoparticles with adjustable diameters over a large range of sizes. The spherical particles obtained show very low polydispersities and a good long term stability. Furthermore it was possible to reveal the growth mechanism of these particles utilizing electron microscopy and optical investigations coupled with theoretical calculations. It was found that there is a formation of small nucleation sites on the surface of the seeds in the beginning of the growth process. These sites then subsequently grow into "blackberry-like" intermediate particles. A final intraparticle ripening step leads to smooth and uniform spherical gold nanoparticles. By correcting the dielectric function of gold for charging and the free mean path effect and taking into account the particle size distribution it was possible to accurately model the optical properties of the gold sols obtained using Mie theory.
By controlling the concentration of chloride ions it was possible to influence both the ripening of the "blackberry-like" shaped particles and the morphology of gold nanoparticles. An increased concentration of the chloride ions in the standard citrate reduction procedure leads to larger and elongated particles, whereas the complete removal of the chloride ions made it possible to obtain star shaped, decahedral and \"desert-rose\" shaped particle morphologies. Using the layer-by-layer technique gold nanoparticles of different sizes could be immobilized on glass substrates. The surface-enhanced Raman scattering intensity of these mixed films were about 60% higher than compared to a film made of a single particle size. The optical properties were further investigated by comparing experimentally obtained UV/Vis spectra with generalized Mie theory simulations.
Additionally it could be shown that tetrazole and its derivatives are suitable stabilizing agents in the aqueous synthesis of silver nanoparticles. It was found that depending on the tetrazole derivative used the tendencies of the nanoparticles to agglomerate vary significantly. Different agglomeration stages have been investigated by UV/Vis and Raman spectroscopy. The removal of the ligands used and a resulting improvement of the applicability of the silver nanostructures as SERS substrates is still a challenge.
In the last part of this work the focus was changed from the optical properties of noble metal nanoparticles to their catalytic properties. Therefore gold and palladium nanoparticles have been successfully immobilized on highly porous zinc oxide aerogels. It was possible to synthesize sponge-, flake-, and ribbon-like zinc oxide gels with high specific surface areas. The facile approach of generating mixed metal oxide/noble metal aerogels is very promising for the preparation of highly selective and highly active heterogenous catalysts. First catalytic investigations of a sponge-like palladium loaded zinc oxide aerogel toward the semi-hydrogenation of acetylene showed very high selectivities of up to 85%.
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陳展榮 and Chin-wing Chan. "Transition metal complexes of quaterpyridines and photochemical studies of cyclometallated gold(III) and platinum(II) complexes." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 1993. http://hub.hku.hk/bib/B31233454.
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Ridley, Paul. "Underpotential deposition of lead on gold and platinum (111) electrode surfaces investigated by scanning tunnelling microscopy." Thesis, University of Liverpool, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.343615.
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Chan, Chin-wing. "Transition metal complexes of quaterpyridines and photochemical studies of cyclometallated gold(III) and platinum(II) complexes /." [Hong Kong : University of Hong Kong], 1993. http://sunzi.lib.hku.hk/hkuto/record.jsp?B13671753.
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Eustis, Susie. "Gold and Silver Nanoparticles: Characterization of their Interesting Optical Properties and the Mechanism of their Photochemical Formation." Diss., Available online, Georgia Institute of Technology, 2006, 2006. http://etd.gatech.edu/theses/available/etd-05262006-130521/.
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Thesis (Ph. D.)--Chemistry and Biochemistry, Georgia Institute of Technology, 2007.<br>Whetten, Robert, Committee Member ; Wang, Z.L., Committee Member ; Perry, Joe, Committee Member ; El-Sayed, Mostafa A., Committee Chair ; Orlando, Thomas, Committee Member.
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Veenboer, Richard M. P. "Synthesis, study and application of NHC-gold(I) complexes." Thesis, University of St Andrews, 2017. http://hdl.handle.net/10023/12169.
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The development of procedures for the synthesis of valuable organic molecules constitutes an important part of chemistry. The goal of improving the efficiency of existing methodologies can be fulfilled by use of metal catalysts. Recent developments in the field of homogeneous gold catalysis have contributed to these efforts and continued investigations assure future innovations. Chapter 1 summarises the properties of gold and ligand-supported gold(I) complexes and demonstrates how a detailed understanding of its reactivity and possible bonding interactions with various substrates facilitates the development of well-defined catalytic systems. Particular attention is given to N-heterocyclic carbenes, highly tunable ligands that stabilise a wide range of different transition metal complexes. Three chapters describe syntheses and studies of known and new complexes. Chapter 2 discusses expedient syntheses of key NHC-gold(I) complexes and catalysts. Chapter 3 constitutes studies to the behaviour of the commonly used tetrafluoroborate counterion in a particular IPrCl -gold(I) complex. Chapter 4 de- scribes the synthesis of a range of IPr-gold(I) carbanion complexes from the widely studied IPr-gold(I) hydroxide synthon, the study of their properties and exploration of their reactivity. Catalytic applications in transformations of alkynes and alcohols are described in the last three chapters. Chapter 5 details the development of efficient NHC-gold(I)-catalysed procedures for the synthesis of vinyl ethers through addition reactions of aliphatic and benzylic alcohols to alkynes. Benzylic alcohols were found to undergo gold-catalysed dehydration under specific conditions and Chapter 6 discloses the NHC-gold(I)-catalysed dehydrative formation of ethers from phenols and benzylic alcohols. Appendix A describes preliminary explorations to the complimentary use of Brønsted acidic compounds as catalysts for the formation of products with new C – C bonds from benzylic alcohols and phenols.
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Roth, Kristina L. "Development of Metal-based Nanomaterials for Biomedical Applications." Diss., Virginia Tech, 2017. http://hdl.handle.net/10919/85365.
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New synthetic advances in the control of nanoparticle size and shape along with the development of new surface modifications facilitates the growing use of nanomaterials in biomedical applications. Of particular interest are functional and biocompatible nanomaterials for sensing, imaging, and drug delivery. The goal of this research is to tailor the function of nanomaterials for biomedical applications by improving the biocompatibility of the systems.
Our work demonstrates both a bottom up and a post synthetic approach for incorporating stability, stealth, and biocompatibility to metal based nanoparticle systems. Two main nanomaterial projects are the focus of this dissertation. We first investigated the development of a green synthetic procedure to produce gold nanoparticles for biological imaging and sensing. The size and morphology of gold nanoparticles directly impact their optical properties, which are important for their function as imaging agents or their use in sensor systems. In this project, a synthetic route based on the natural process of biomineralization was developed, where a designed protein scaffold initiates the nucleation and subsequent growth of gold ions. To gain insight into controlling the size and morphology of the synthesized nanoparticles, interactions between the gold ions and the protein surface were studied along with the effect of ionic strength on interactions and then subsequent crystal growth. We are able to control the size and morphology of the gold nanoparticles by altering the concentration or identity of protein scaffold, salt, or reducing agent.
The second project involves the design and optimization of metal organic framework nanoparticles for an external stimulus triggered drug delivery system. This work demonstrates the advantages of using surface coatings for improved stability and functionalization. We show that the addition of a polyethylene glycol surface coating improved the colloidal stability and biocompatibility of the system. The nanoparticle was shown to successfully encapsulate a variety of small molecule cargo. This is the first report of photo-triggered degradation and subsequent release of the loaded cargo as a mechanism of stimuli-controlled drug delivery. Each of the aforementioned projects demonstrates the design, synthesis, and optimization of metal-based systems for use in biomedical applications.<br>Ph. D.
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Yan, Kun, and 嚴琨. "Proteomic and biochemical studies of cytotoxic gold(I), silver(I) and rhodium(II) complexes." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2007. http://hub.hku.hk/bib/B3963436X.
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