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Leung, Siu Ling. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2009. / Includes bibliographical references (leaves 60-62). / Abstracts in English and Chinese. / Table of Contents / ACKNOWLEDGEMENT --- p.4 / List of Figures --- p.8 / Chapter 1. --- Introduction --- p.11 / Chapter 1.1 --- Background --- p.11 / Chapter 1.2 --- Project Objective --- p.12 / Chapter 1.3 --- Organization of the Thesis --- p.13 / Chapter 2. --- Literature Review --- p.14 / Chapter 2.1 --- Overview of the Colloidal Gold --- p.14 / Chapter 2.2 --- Dielectrophoresis (DEP) --- p.14 / Chapter 2.2.1 --- CM factor of Single Shell Model --- p.16 / Chapter 2.3 --- Double Layer and AC Electroosmosis --- p.18 / Chapter 2.3.1 --- Double Layer --- p.18 / Chapter 2.3.2 --- AC Electroosmosis --- p.19 / Chapter 2.4 --- Electrothermal Body Force --- p.19 / Chapter 3. --- Theoretical Analysis of DEP Manipulation --- p.21 / Chapter 3.1 --- Particle Manipulation by DEP Force --- p.21 / Chapter 3.2 --- Electric Induced Fluid Flow --- p.22 / Chapter 3.2.1 --- Double Layer and AC Electroosmosis --- p.22 / Chapter 3.2.2 --- Electrothermal Body Force --- p.24 / Chapter 3.3 --- DEP Manipulation against Fluid Flow --- p.25 / Chapter 4. --- Fabrication of AuNP based Sensors --- p.28 / Chapter 4.1 --- Fabrication of Arrays of Microelectrodes --- p.28 / Chapter 4.2 --- Formation of AuNP based Pearl Chains across Microelectrodes --- p.30 / Chapter 4.2.1 --- Formation Circuit --- p.30 / Chapter 4.2.2 --- Microspotting System --- p.31 / Chapter 4.2.3 --- Results and Discussion --- p.32 / Chapter 5. --- Exploring the Critical Parameters in Controlling AuNP Pearl Chain Formation (PCF) --- p.35 / Chapter 5.1 --- Exploring the Optimum Frequencies --- p.35 / Chapter 5.1.1 --- Analyzing the observation of pearl chain formation under specific frequency ranges --- p.36 / Chapter 5.1.2 --- Conclusion on the Optimum Frequency for PCF --- p.40 / Chapter 5.2 --- Exploring the Optimum Voltages --- p.41 / Chapter 5.3 --- Influence of the Particle size on the Formation Rate --- p.43 / Chapter 6. --- Characteristics of the AuNP based Pearl Chain --- p.44 / Chapter 6.1 --- I-V Characteristics --- p.44 / Chapter 6.2 --- Thermal Sensitivities --- p.45 / Chapter 7. --- Application of the AuNP based Sensor - Airflow Sensor --- p.48 / Chapter 7.1 --- Experimental Setup --- p.48 / Chapter 7.2 --- Experimental Results --- p.49 / Chapter 7.2.1 --- Sensor Response to Air --- p.49 / Chapter 7.2.2 --- Sensor Response to Nitrogen Gas --- p.50 / Chapter 7.2.3 --- Control Experiment --- p.51 / Chapter 7.3 --- Discussions --- p.53 / Chapter 7.3.1 --- Relationship between the Measured Electric Response and Temperature --- p.54 / Chapter 7.3.2 --- Pressure-Temperature Relationship of the Sensor --- p.55 / Chapter 8. --- Conclusion --- p.57 / Chapter 9. --- Future Work --- p.58 / Chapter 9.1 --- DEP Manipulation of 2nm diameter gold nanoparticles --- p.58 / References --- p.60 / List of Publications --- p.63 / APPENDIX-I / The Clausius-Mossoti (CM) Factor --- p.64 / Chapter I-1 --- The CM factor of homogeneous dielectric spheres --- p.64 / Chapter I-2 --- The CM factor of a single shell sphere --- p.65 / APPENPIX-II / Estimating the Minimum Voltage for Electrolysis by the Nernst Equation [39] --- p.67 / Chapter II-l --- Gibb´ةs Free Energy and the Nernst Equation --- p.67 / Chapter II-2 --- Minimum Voltage Required for Electrolysis of Water with Different pH --- p.67 / Appendix-III / Temperature-Voltage Relationship of the K-type Thermocouple [40] --- p.69 / Appendix-IV / Mathlab Program --- p.70 / Chapter IV-1. --- Fluid velocity induced by AC electroosmosis --- p.70 / Chapter IV-2. --- Voltage drop across the double layer --- p.70 / Chapter IV-3. --- Fluid velocity induced by electrothermal force --- p.71 / Chapter IV-4. --- CM Factor Simulation --- p.72 / Chapter IV-5. --- Particle velocity induced by DEP force --- p.73

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Precision measurements of the Debye-Waller factor of Fe57 in Au using the wide black absorber technique have been made in the temperature range from room temperature to 830 K. The major source of error arises from Au Ly x-rays which are unresolved by the radiation detection system from the 14.4 KeV gamma ray. The K absorption edge of Br has been used to correct for the presence of x-rays. These measurements have revealed the existence of two nonequivalent lattice sites which the Co57 impurity (parent of Fe57) may occupy. One of the sites has been populated by quenching the source from temperatures greater than 1150 K and has been identified as a substitutional lattice site. From an analysis of the Mössbauer spectrum it is concluded that some of the substitutional sites may be in the vicinity of dislocations. It has been determined that the impurity-host force constant for Fe57 atoms in the substitutional site is about the same as the host-host force constant; the experimental value of the anharmonicity parameter ɛ (-2) for Fe57 in the Au is nearly the same as calculated values of ɛ (-2) for pure Au. The second site forms very slowly upon annealing the source at intermediate temperatures and has been identified as being interstitial in character. The slow rate of formation of the interstitial site indicates that diffusion is a primary mechanism in its formation. The second site must therefore be more complicated than an ordinary interstitial. It is proposed that this site is a split, or dumbbell, interstitial formed by substituting two impurity atoms for one of the Au atoms.

New cycloaurated complexes have been synthesised and characterised. The biological and catalytic activity (in the addition of 2-methylfuran to methyl vinyl ketone) of selected complexes was evaluated. New complexes reported in this thesis where fully characterised by NMR (¹H, ¹³C and ³¹P when appropriate) and IR spectroscopy, ESI-mass spectrometry and elemental analysis. The simple cycloaurated iminophosphoranes (2-AuCl₂C₆H₄)Ph₂P=N-R (R = (R,S)-CHMePh, (S)-CHMePh, p-C₆H₄F or But) were synthesised by the reaction of the appropriate ortho-mercurated compound with [Me₄N][AuCl₄] and [Me₄N]Cl in acetonitrile; the complex (2-AuCl₂C₆H₄)Ph₂P=N-(S)-CHMePh was structurally characterised. The cis chloride ligands on the complexes were replaced by chelating dianionic ligands such as thiosalicylate and catecholate - the resulting bis-metallacyclic complexes have a better anti-tumour activity (against P388 murine leukemia cells) than the parent dichlorides. The nitrogen-gold coordinate bond is relatively robust and is not cleaved by cyanide or dithiocarbamate ligands. The reaction of (2-AuCl₂C₆H₄)Ph₂P=N-Ph with PPh₃ results in substitution of the chloride ligand trans to the nitrogen (shown by an X-ray crystal structure). Both the endo ((2-AuCl₂C₆H₄)Ph₂P=NC(O)Ph) and exo ((2-AuCl₂C₆H₄)C(O)N=PPh₃) cycloaurated isomers of the stabilised iminophosphorane Ph₃P=NC(O)Ph were synthesised and structurally characterised. Cycloaurated Ph₃P=S and Ph₃P=Se were synthesised by a transmetallation reaction from 2-Hg[(C₆H₄)P(E)Ph₂]₂ (E = S or Se). The synthesis of cycloaurated Ph₃P=O by an analogous method was unsuccessful. PhP(S)(NEt₂)₂ was also cycloaurated via a transmetallation reaction. X-ray crystallography confirmed the sulfur (not the nitrogen) was coordinated to the gold centre. The complexes show a similar stability and reactivity to the C,N cycloaurated species - the cis chloride ligands can be replaced by the chelating thiosalicylate ligand. Again the bis-metallacyclic species showed better biological activity than the parent dichloride. The direct reaction of the 2-pyridyl sulfonamide ligands 2-(C₅H₅N)CH₂NHSO₂R (R = p-tolyl, Ph or Me), 2-(C₅H₅N)CH₂CH₂NHSO₂R (R = p-tolyl or Ph) or 8-(p-tosylamino)quinoline with refluxing aqueous H[AuCl₄] gave N,N' coordinated complexes containing a five- or six-membered cycloaurated ring. The cycloaurated complexes derived from the ligands 2-(C₅H₅N)CH₂NHSO₂Me and 8-(p-tosylamino)quinoline were structurally characterised. The cycloaurated N,N' systems were not as stable as the C,N systems - reaction with reducing agents led to reduction of Au(III) to Au(I) and elemental gold. The 2-pyridine thiocarboxamide ligands 2-(C₅H₅N)C(S)NHR (R= p-tolyl, CH₂Ph, Me, p-C₆H₅OMe) also underwent direct cycloauration upon reaction with H[AuCl₄]. Coordination via the pyridyl nitrogen and sulfur atom was confirmed by an X-ray crystal structure of cycloaurated 2-(C₅H₅N)C(S)NHCH₂Ph. The N,S cycloaurated systems show poor stability in solution and decompose relatively quickly so applications are limited. The ligand with a 2 pyridyl substituent reacted with H[AuCl₄] in a different manner. Instead of cycloauration, the ligand was oxidised and an internal cyclisation occurred to give a 1,2,4-thiadiazolo[2,3-a]pyridinium heterocyclic ring. The reaction of the cycloaurated dichloride complexes (2-benzylpyridine)AuCl₂ and (2-AuCl₂C₆H₄)Ph₂P=N-Ph with the tripodal Kläui ligands (Na[(C₅H₅)Co{P(O)R₂}₃], R = OMe or OEt) and Tl[BF₄] resulted in the formation of cationic gold(III) salts. In the solid state the Kläui ligand is strongly coordinated through two of the three oxygen atoms, and weakly by the third, giving the gold a distorted square pyramidal geometry. In solution there is rapid interchange between the coordinated and non-coordinated oxygen atoms.

Rich gold-telluride lodes (steeply dipping and flatly dipping) and minor gold-quartz stockwork mineralization characterize the Kalgoorlie gold-field. The origin of these gold deposits, the relationship between deposits and then nature of the host rocks are the major problems considered in this thesis. Extensive diamond drilling at the essentially unmineralized southern end of the field provided excellent material for stratigraphic studies and for country rock analysis whilst ore samples were obtained from both mines and drill core.

Rich gold-telluride lodes (steeply dipping and flatly dipping) and minor gold-quartz stockwork mineralization characterize the Kalgoorlie gold-field. The origin of these gold deposits, the relationship between deposits and then nature of the host rocks are the major problems considered in this thesis. Extensive diamond drilling at the essentially unmineralized southern end of the field provided excellent material for stratigraphic studies and for country rock analysis whilst ore samples were obtained from both mines and drill core.

Thesis (M.S.)--University of Wisconsin--Madison, 1984. / Typescript. Title from title screen (viewed Mar. 27, 2007). Includes bibliographical references (leaves 47-50). Online version of the print original.

Six distinct types of mafic igneous rocks are present within the ca. 2714-2690 Ma Woolyeenyer Formation of the Norseman Terrane, East Central Yilgarn Superterrane (ECYS), Yilgarn Block, Western Australia. (1) Tholeiitic basalts and gabbros comprise the bulk of the formation, and are characterized by flat to slightly depleted mantle-normalized incompatible element patterns, and å_Nd values of +2 to +3. (2) High-MgO tholeiite dykes (HMT) with normalized REE and multielement patterns like those of tholeiites, albeit at slightly lower abundances. (3) Enriched high-MgO tholeiite dikes (EHMT) with MgO, Cr similar to HMT but with extreme Al-depletion, enrichment in incompatible elements and HREE depletion, and å_Nd values of -2.0 to -1.2. (4) High-MgO tholeiites with characteristics transitional to HMT and EHMT (THMT). Incompatible element enriched tholeiites transitional between HMT, HMT and tholeiite, subdivided into (5) ET1, characterized by enrichment in incompatibleelements and LREE, with relatively flat HREE patterns and ENd values ranging from -0.1 to 1.0, and (6) ET2, characterized by Al-depletion and pronounced HREE depletion. The HMT and tholeiites are comagmatic, and positive ENd values and comparable normalized trace element patterns suggest derivation of these rocks from a similar depleted source. Conversely, detailed modelling demonstrates that EHMT compositions cannot be generated by alteration or crustal contamination of HMT, Al-undepleted or Al-depleted komatiitic magmas, and require a source (1) that was enriched in incompatible elements by small volume partial melts prior to melting, and (2) where garnet was retained during melting. Generation of the above mafic lithologies require that incompatible element enriched and depleted sources existed at 2.7 Ga in the Norseman Terrane. The EHMT are the first report of such severely Al-depleted 2.7 Ga rocks from ECYS. The Archean lode-gold deposits at Norseman, Western Australia, consist of auriferous quartz veins in dextral-reverse ductile shear zones within tholeiitic metabasalts of upper-greenschist to amphibolite facies metamorphic grade. Three types of deposits (northern, central, southern) are delineated on the basis of their spatial distribution, veining style, alteration mineralogy and metamorphic grade of host rocks. All deposits exhibit variable ductile deformation of veins and contiguous alteration haloes, implying a syn-deformational genesis at high temperatures. From Northern to Southern deposits, the alteration assemblages are indicative of higher temperatures, and there are progressively greater degrees of dynamically recovered textures in quartz. Initial Pb isotope compositions of galena and altaite from lode gold deposits of the Norseman Terrane yield the most variable initial Pb-isotopic compositions for these minerals of any Archean lode gold deposit. Interpreted initial Pb isotope compositions of galena and altaite are systematically more radiogenic with increasing proximity to felsic intrusive rocks and older crust.

For more than a decade nanomaterials have attained huge attraction owing to the exceptionally different and excellent characteristics as compared to their bulk form. In the present research, we focus on understanding the properties and performance of nanocomposites in solid and liquid states. There are three major areas involved in this thesis research. Firstly, we will identify effective methods or techniques to evaluate nanomaterials. Conventional and non-conventional techniques will be implied. The second part is to study the interfacial reactions between nanoparticles (NPs) and fluid molecules. This is to obtain basic understanding of nanoparticles and their interactions with matrix materials. Thirdly, we will investigate the mechanical properties of nanocomposites. Experimental results showed that the mechanical properties of nanocomposites measured at macroscale exhibited differences when the shape and size of gold NPs were changed. The morphological characteristics of the material were shown effectively at the nanoscale based on the NPs' shape and size. The properties of NPs influenced the properties of gold colloid. Such changes were the result of the interfacial interaction of gold NPs and the host material.