This research investigated the tribological performance of a composite material, formed from an ultra high molecular weight polyethylene (UHMWPE) matrix and quasicrystalline Al-Cu-Fe alloy powders. An evaluation was conducted for the microstructure, material properties, and tribological performance of quasicrystalline materials formed from Al-Cu-Fe alloys. Arc melting was used as the fabrication technique for these alloys, and some samples were additionally heat treated in an argon environment. Vickers microhardness testing was done to make comparisons to wear rate behavior of the various alloys. Tribological studies were conducted using a linear pinon- desk configuration to evaluate friction and wear. Research indicated the annealed samples of Al-Cu-Fe that formed icosahedral quasicrystalline phases, where the quasicrystalline phase was most dominant of the observed alloys, displayed the greatest wear resistance and hardness. Abrasive wear was observed in each of the samples, as the brittle, hard nature of the quasicrystalline phase would not allow for the ductile adhesion. The addition of small amounts of Al-Cu-Fe quasicrystalline particles, crushed and pulverized from the arc-melted ingots, reduced the coefficient of friction and wear rate of UHMWPE, when added to the polymer.

The objective of this thesis is to explore new reactivities and to improve luminescent properties of 7-azaindole-containing metal complexes. Selectivity for the activation of toluene and ethyl benzene has been investigated with two cationic Pt(II)(N,N-L) complexes, where N,N-L = 1,2-bis(1-N-7-azaindolyl)benzene (BAB) or bis(1-N-7-azaindolyl)methane (BAM). A high regioselectivity toward toluene and ethyl benzene benzylic C-H activation and a distinct diastereoselectivity for ethyl benzene benzylic C-H activation are demonstrated. Detailed mechanistic studies have been performed, leading to the establishment of both the intermediacy of the η3-benzylic Pt(II) complexes in the reactions and the ligand steric impacts as origins for the distinct diastereoselectivity. A PtMe2 complex of 1-N-(pyridin-2-yl)-7-azaindole (NPA) has been synthesized and found to undergo facile transformation at ambient temperature, resulting in the quantitive formation of a neutral Pt4 molecular square. The mechanism of the transformation process has been examined, establishing a distinct intramolecular C-H driven self-assembly process. The geometrical impacts of the BAB and BAM ligands on the structure and stability of their fac-Pt(IV)Me3 complexes has been investigated. The BAB ligand is more effective than the BAM ligand in stabilizing the five-coordinate Pt(IV)Me3 complexes. With the BAB ligand, a five-coordinate fac-Pt(IV)Me3 complex is obtained; with the BAM ligand, two six-coordinate fac-Pt(IV)Me3 complexes are obtained. In solution, the methyl groups in the BAB complex exchange slowly, but those in the BAM complexes exchange rapidly. Several new 7-azaindolyl derivative ligands via either modifying or altering the BAM and BAB bridging groups have been developed. The syntheses, structures and reactivities of their Pt(II) complexes have been examined, leading to the finding of an unconventional C-Sn oxidative addition reaction. The modification of the NPA ligand via the incorporation of a triarylboron group has been carried out. Several novel Pt(II) and Cu(I) complexes have been synthesized and studied. A Cu(I) complex is found to display exceptionally bright ambient temperature phosphorescence. A series of dinuclear Cu(I) compounds of the 1,2,3,4-tetra(1-N-7-azaindolyl)benzene (TTAB) ligand have been synthesized and examined. The close contacts between the TTAB bridging phenyl ring and the Cu(I) centers are present in the complexes. / Thesis (Ph.D, Chemistry) -- Queen's University, 2008-05-21 18:10:58.628

The objective of this thesis is to examine the photophysical and structural properties of Cu(I) complexes of 2-(2’-pyridyl)benzimidazolyl based ligands and Cu(I), Pd(II) and Pt(II) complexes of 2-(2’-pyridyl)indolyl based ligands, for possible use as phosphorescent emitters in OLEDs. The discovery of the atropisomeric 3,3’-bis(2-(2’-pyridyl)indolyl based ligands led to the examination of C-C coupling reactions and the investigation of the new chiral ligands with transition metal ions. Cu(I) complexes of 2-(2’pyridyl)benzimidazolyl-benzene with varying phosphine ligands were prepared. The structures were studied with X-ray crystallography and NMR. Experimental and computational results established that steric and electronic properties of the phosphine ligands influence the photophysical properties of the Cu(I) complexes. Polynuclear Cu(I) complexes with 2-(2’-pyridyl)benzimidazolyl based ligands and two PPh3 ancillary ligands were synthesized, the photoluminescent and electroluminescent properties were examined. A series of 2-(2’-pyridyl)indolyl based ligands; 2-(2’-pyridyl)indolyl-benzene (pib), 1,4-bis[2-(2’-pyridyl)indolyl]benzene (bib) and 1,3,5-tris[2-(2’-pyridyl)indolyl]benzene) (tib) and the corresponding C-C coupled dimers bis[3,3’(2-(2’-pyridyl)indolyl-benzene)] (bpib), bis[3,3’(1,4-bis[2-(2’-pyridyl)indolyl]benzene (bbib) and bis[3,3’(1,3,5-tris[2-(2’-pyridyl)indolyl]benzene)] (btib) were synthesized in a one-pot reaction with the formation of both C-N and C-C bonds. The photophysical properties of these new molecules were investigated. The dimers display intramolecular exciplex formation. The rotation barrier around the C-C bond in the 3 position of the bis-indole was calculated using DFT which support that bpib is an atropisomeric ligand. Cu(I), Pd(II) and Pt(II) complexes were synthesized with pib and bpib. [Cu(pib)(PPh3)2]+ contains a three-coordinate Cu(I) ion and doesn’t display MLCT but rather 3π-1π phosphorescence. In Pd(pib)(acac) and Pt(pib)(DMSO)Cl the pib ligand forms C,N chelated neutral complexes that display red emission in frozen solution and in solid state. The X-ray crystal structure for [Cu(bpib)2]+ revealed a homo-chiral crystal and for Pd(bpib)Cl2 and Pt(bpib)Cl¬2 show a trans-chelating geometry around the metal centre. Frozen solutions of [Cu(bpib)2]+ and Pd(bpib)Cl2 display MCLT phosphorescence. Finally the atropisomeric ligands bpib and bbib were examined as sensors to determine the enantiomeric excess of Zn(2-bromo-3-methylbutyrate)2 by CD spectroscopy. CD and fluorescent titration experiments verified that these ligands have selective interactions with different Zn(II) carboxylates. DFT computations showed that diastereomeric excess caused by chiral discrimination leads to the CD spectral-response of the atropisomeric ligands toward chiral Zn(II) carboxylates. / Thesis (Ph.D, Chemistry) -- Queen's University, 2008-09-25 09:54:21.464

The plant cell wall contains significant quantities of renewable polymers in the form of cellulose, hemicellulose, and lignin. These three renewable polymers have the potential to complement or replace synthetic polymers in a variety of applications. Rapidly determining the quantities of these polysaccharides in lignocellulosic biomass is important yet difficult since plant biomass is recalcitrant and highly variable in composition. Part of this contribution outlines a novel compositional analysis protocol using infrared spectroscopy and multivariate regression techniques that is rapid and inexpensive. Multivariate regression models based on calibration mixtures can be used to discern between populations of lignocellulosic biomass or to predict cellulose, hemicellulose, and lignin quantities. Thus, the compositional analysis step can be expedited so that other processes, like fractionation of the lignocellulose polymers, can be tuned accordingly to maximize the value of the final product. Hybrid materials were also generated using a variety of polymerization techniques and post-polymerization modifications. A novel controlled/living radical polymerization initiator was synthesized (2-bromo-2-methylpropane hydrazide) containing a hydrazide functionality that was covalently linked to the reducing-end of dextran. Despite the rapid coupling of the hydrazide- based initiator to the reducing-end of dextran, the instability of the alkyl bromide bond resulted in several unsuccessful attempts at Cu(0)-mediated controlled/living radical polymerization. Recommendations were given to improve the stability of this compound; however, an alternative approach to synthesizing hybrid copolymers was also investigated in parallel. Hyperbranched polymers were synthesized using commercially available vinyl and divinyl monomers in the presence of a cobalt(II) complex that enabled control over the size, architecture, and mol% of pendant vinyl groups amenable to post-polymerization modification. Modifying the ratio of divinyl monomer to cobalt(II) complex provided a series of hyperbranched polymers with variable morphology and mol% pendant vinyl groups. The pendant vinyl bonds were subsequently converted to amines via thiol additions with cysteamine. These amine functionalized hyperbranched polymers were then used in a subsequent reductive amination reaction with the reducing-end of dextran to produce the amphiphilic core-shell copolymer poly(methyl methacrylate-co-ethylene glycol dimethacrylate)-b-dextran. These amphiphilic copolymers mimicked the colloidal behaviour of conventional block copolymer micelles without requiring difficult syntheses or tedious self-assembly steps. / Thesis (Master, Chemical Engineering) -- Queen's University, 2012-02-28 11:20:01.568

No description available.

Copper-organonitrogen complexes are studied by threshold photoionization and zero electron kinetic energy photoelectron spectroscopy. These complexes are prepared in pulsed laser vaporization supersonic molecular beams. Adiabatic ionization energies of the neutral species and vibrational frequencies of the neutral and ionic complexes were measured. Metal-ligand bond dissociation energies were obtained from the theoretical calculations or the experiments. More importantly, by combining the spectroscopic measurements, quantum chemical calculations, and spectral simulations, metal-ligand bonding structures are determined for copper complexes of diamines, pyridine, diazines, aminopyridines, polypyridines, and imidazole. The Cu-ethylenediamine, -(1,3-propanediamine), and -(1,4-butenediamine) complexes have been determined to be in a hydrogen-bond stabilized monodentate configuration. However, Cu atom binds to both two nitrogens in the methyl-substituted ethylenediamines. The change of the Cu binding from the monodentate to the bidentate mode arises from the competition between copper coordination and hydrogen bonding. Although pyridine, diazines, and imidazole molecules can function as a s-donor through the nitrogen atom, a p-acceptor or p-donor through six-membered or five-membered aromatic ring, only the s bonding mode is predicted by the theory and identified by the ZEKE spectroscopy. For aminopyridine molecules, s bonding through the sp2 or sp3 hybrid electron lone pair and p bonding through the pyridine ring are possible. Yet, the s bonding through the sp2 electron donation is calculated to be the strongest, and the Cuaminopyridine complexes formed by such bonding mechanism are identified by the experiments. Moreover, monodentate Cu-(4,4'-bipyridine), bidentate Cu-(2,2'-bipyridine) and Cu-(1,10-phenanthroline), and tridentate Cu-(2,2':6',2?-terpyridine) are established to be the most stable structure and are observed by experiments. It is surprising to find that the tridendate planar structure of Cu-(2,2':6',2?-terpyridine) changes to a twisted Cs structure upon ionization.

No description available.

The West Ansil deposit was the first Cu discovery in 25 years in the Noranda Central Camp. It has a combined indicated and inferred resource of ~1.2 Mt. Grades for the indicated resource are 3.4% Cu, 0.4% Zn, 1.4 g/t Au and 9.2 g/t Ag. The bulk of the resource is located in three massive sulphide lenses (Upper, Middle and Lower) that are entirely within the Rusty Ridge Formation above the Lewis exhalite. The mineralization in all three ore lenses consists of massive pyrrhotite + chalcopyrite + magnetite. Semi-massive sphalerite is restricted to the upper and lower parts of the Middle lens. Massive magnetite occurs at the center of the Upper and Middle lenses, where it replaces massive pyrrhotite. A striking feature of West Ansil is the presence of abundant colloform and nodular pyrite (+marcasite) in the massive sulphides. Late-stage replacement of massive pyrrhotite by colloform pyrite and marcasite, occurs mostly along the upper and lower contacts of the lenses.

Homogenization of alloying elements is desired during sintering of powder metallurgy components. The redistribution processes such as penetration of liquid phase into the interparticle/grain boundaries of solid particles and subsequent solid-state  diffusion of alloy element(s) in the base powder, are important for the effective homogenization of alloy element(s) during liquid phase sintering of the mixed powders. The aim of this study is to increase the understanding of alloy element redistribution processes and their effect on the dimensional properties of the compact by means of numerical and experimental techniques. The phase field model coupled with Navier-Stokes equations is used for the simulations of dynamic wetting of millimeter- and micrometer-sized metal drops and liquid phase penetration into interparticle boundaries. The simulations of solid particle rearrangement under the action of capillary forces exerted by the liquid phase are carried out by using the equilibrium equation for a linear elastic material. Thermodynamic and kinetic calculations are performed to predict the phase diagram and the diffusion distances respectively. The test materials used for the experimental studies are three different powder mixes; Fe-2%Cu, Fe-2%Cu-0.5%C, and Fe-2%(Cu-2%Ni-1.5%Si)-0.5%C. Light optical microscopy, energy dispersive X-ray spectroscopy and dilatometry are used to study the microstructure, kinetics of the liquid phase penetration, solid-state diffusion of the Cu, and the dimensional changes during sintering. The wetting simulations are verified by matching the spreading experiments of millimeter-sized metal drops and it is observed that wetting kinetics is much faster for a micrometer-sized drop compared to the millimeter-sized drop. The simulations predicted the liquid phase penetration kinetics and the motion of solid particles during the primary rearrangement stage of liquid phase sintering in agreement with the analytical model. Microscopy revealed that the C addition delayed the penetration of the Cu rich liquid phase into interparticle/grain boundaries of Fe particles, especially into the grain boundaries of large Fe particles, and consequently the Cu diffusion in Fe is also delayed. We propose that the relatively lower magnitude of the sudden volumetric expansion in the master alloy system could be due to the continuous melting of liquid forming master alloy particles. / <p>QC 20140515</p>

The limitations of the conventional Cu/low-k interconnect technology for use in future ultra-scaled integrated circuits down to 7 nm in the year 2020 are investigated from the power/performance point of view. Compact models are used to demonstrate the impacts of various interconnect process parameters, for instance, the interconnect barrier/liner bilayer thickness and aspect ratio, on the design and optimization of a multilevel interconnect network. A framework to perform a sensitivity analysis for the circuit behavior to interconnect process parameters is created for future FinFET CMOS technology nodes. Multiple predictive cell libraries down to the 7‒nm technology node are constructed to enable early investigation of the electronic chip performance using commercial electronic design automation (EDA) tools with real chip information. Findings indicated new opportunities that arise for emerging novel interconnect technologies from the materials and process perspectives. These opportunities are evaluated based on potential benefits that are quantified with rigorous circuit-level simulations and requirements for key parameters are underlined. The impacts of various emerging interconnect technologies on the performances of emerging devices are analyzed to quantify the realistic circuit- and system-level benefits that these new switches can offer.