Nanochannel devices have been explored over the years with wide applications in bio/chemical analysis. With a dimension comparable to many bio-samples, such as proteins, viruses and DNA, nanochannels can be used as a platform to manipulate and detect such analytes with unique advantages. As a prerequisite to the development of nanochannel devices, various nanofabrication techniques have been investigated by many researchers for decades. In this dissertation, three different fabrication approaches for nanochannels are discussed, including a novel scanning coaxial electrospinning process, a heat-induced stretching approach and a standard contact photolithography process. The scanning coaxial electrospinning process is established based on conventional electrospinning process. A coaxial jet, with the motor oil as the core and spin-on-glass-coating/PVP solution as the shell, is deposited on the rotating collector as oriented coaxial nanofibers. These nanofibers are then annealed to eliminate the core material and form the hollow interior. Silica nanochannels with an inner diameter as small as 15 nm were obtained. The heat-induced stretching approach includes using commercially available fused silica tubings to create nanochannels by thermal deforming. This method and the electrospinning technique both focus on fabricate one-dimensional nanochannels with a circular opening. Fluorescent dye was used as a testing sample for single molecule detection and electrokinetic analysis in the resultant nanochannels. Another nanochannel device described in this dissertation has a deep-shallow step structure. It was fabricated by standard contact lithography, followed by etching and bonding. This device was applied as a powerful detection platform for surface-enhanced Raman spectroscopy (SERS). The experiment results proved that it is able to highly improve the sensitivity and efficiency of SERS. The SERS enhancement factor obtained from the device is 108. Moreover, the molecule enrichment effect of this device provides an extra 105 enhancement. The detection can be efficiently finished within minutes after simply loading the mixture of analytes solution and gold nanoparticles in the device. The sample consumption is in micro-liter range. Potential applications in diagnostics, prognositics and water pollutants detection could be achieved using this device.

It is generally believed that the Si technology is going to hit a road block soon. Amongst all the potential candidates, graphene shows the most promise as replacement material for the aging Si technology. This has caused a tremendous stir in the scientific community. This excitement stems from the fact that graphene exhibits unique electronic properties. Physically, it is a two-dimensional network of sp₂bonded carbon atoms. The unique symmetry of two equivalent sublattices gives rise to a linear energy dispersion for the charge carriers. As a consequence, the charge carriers behave like massless Dirac particles with a constant speed of c/300, where c is the speed of light. The sublattice symmetry gives rise to unique half-integer quantum hall effect, Klein's paradox, and weak antilocalization. In this research work, I was able to successfully study the growth and electronic structure of EG on SiC(0001), in ultra-high vacuum and low-vacuum furnace environment. I used STM to study the growth at an atomic scale and macroscopic scale. With STM imaging, I studied the distinct properties of commonly observed interface region (layer 0), first graphene layer, and the second graphene layer. I was able to clearly resolve graphene lattice in both layer 1 and 2. High resolution imaging of the defects showed a unique scattering pattern. Raman spectroscopy measurements were done to resolve the layer dependent signatures of EG. The characteristic Raman 2D peak was found to be suppressed in layer 1, and a single Lorentzian was seen in layer 2. Ni metal islands were grown on EG by e-beam deposition. STM/ STS measurements were done to study the changes in doping and the electronic structure of EG with distance from the metal islands.

<p>This thesis describes the synthesis, structure, equilibriaand other properties of novel thallium(III) monomeric andplatinum-bonded complexes with nitrogen donor ligandsethylenediamine, diethylenetriamine, triethylenetetramine,porphyrin, 2,2'-bipyridine and 1,10-phenanthroline in solutionand in solid.</p><p>The existence of three complexes withthe general formula[Tl(en)_n]³⁺(n = 1-3) and their overall stability constantshave been established in pyridine. All three complexes wereidentified by their²⁰⁵Tl and¹H NMR chemical shifts and²⁰⁵Tl-¹H coupling constants. The formation process of thecomplexes was followed by¹H NMR spectroscopy. The crystal structure of[Tl(en)₃](ClO₄)₃was determined; the thallium(III) ion isN-coordinated in a distorted octahedral geometry. Two [Tl(dien)_n]³⁺(n = 1-2) complexes were proved to exist insolution and the structure of the bis-complex [Tl(dien)₂]²⁺in<i>u-facial</i>isomers was determined in solid. In addition,crystal structures of [Tl(en)₂CN](ClO₄)₂with cyanide bridging between two Tl(en)₂units forming an infinite chain structure and of[Tl(tren)₂(CN)₂](ClO₄) with a distorted pseudo-octahedral coordinationaround thallium were determined. Thallium(III) complexes with2,2'-bipyridine and 1,10-phenanthroline have been studied inDMSO using²⁰⁵Tl,¹³C and¹H NMR spectroscopy. In addition, aseven-coordinated thallium was found in the crystal structureof [Tl(bipy)₃(dmso)](ClO₄)₃, and six-coordinated thallium in pseudo-octahedralgeometry in [Tl(phen)₂Cl₂](ClO₄).</p><p>The solvated complex [Tl(dmso)₆]³⁺has been prepared using concentrated aqueoussolution of Tl(ClO₄)₃by a solvent replacement reaction in DMSO, and thewater-free solid compound [Tl(dmso)₆](ClO₄)₃was crystallized from DMSO. The structure of thecomplex [Tl(dmso)₆]³⁺is a regular octahedron with the Tl-O bonddistance 2.224(3) Å. It represents an easy and secure wayto introduce water-free Tl(III) into organic phase withoutreduction.</p><p>Through several reactions, novel heteronuclear Pt-Tlcomplexes with the composition [(NC)₅Pt-Tl(tpp)]^2-, [(NC)₅Pt-Tl(thpp)]^2-, [(NC)₅Pt-Tl(bipy)_n](n = 1-2), [(NC)₅Pt-Tl(en)_n-1](n = 1-3) and [(NC)₅Pt-Tl(phen)_n](n = 1-2), have been synthesized in solution.Multinuclear NMR (¹⁹⁵Pt,²⁰⁵Tl,¹³C and¹H), Raman spectroscopy and X-ray diffraction dataare fully compatible with formation of unsupported Pt-Tl bondedcomplexes both in solution and in solid. The huge¹J(¹⁹⁵Pt-²⁰⁵Tl) spin-spin coupling constants (48-66 kHz) wereobserved by both¹⁹⁵Pt and²⁰⁵Tl NMR spectroscopy in solution and they providea strong evidence of formation of the Pt-Tl bond in solution.In all six determined crystal structures of the Pt-Tl compoundsa very short Pt-Tl bond is found with distances2.6117(5)-2.6375(5) Å. The calculated values of Pt-Tlforce constants (1.38-1.91 N/cm) are characteristic for asingle metal-metal bond.</p><p>In the Pt-Tl compounds, the oxidation state of the metalions is intermediate between the stable states Pt^II/Pt^IVand Tl^III/Tl^I, respectively, and this is reflected by their¹⁹⁵Pt and²⁰⁵Tl chemical shifts. It turns out that N-donorligands can really stabilize the Pt-Tl bond both in solutionand in solid. The character of the metal-metal bond anditstheoretical basis are discussed.</p><p><b>Keywords:</b>Thallium, Platinum, Cyanide, N-donor ligand,Metal-metal bond, Multinuclear NMR, Raman spectroscopy, X-raydiffraction, Equilibrium, Spin-spin coupling.</p>

<p>Rechargeable batteries play an important role as energycarriers in our modern society, being present in wirelessdevices for everyday use such as cellular phones, video camerasand laptops, and also in hybrid electric cars. The batterytechnology dominating the market today is the lithium-ion(Li-ion) battery. Battery developments, in terms of improvedcapacity, performance and safety, are major tasks for bothindustry and academic research. The performance and safety ofthese batteries are greatly influenced by transport andstability properties of the electrolyte; however, both haveproven difficult to characterise properly.</p><p>The specific aim of this work was to characterise and modelthe electrolytes used in Li-ion batteries. In particular, themass transport in these electrolytes was studied throughcharacterisation and modelling of electrolyte transport in bulkand in porous electrodes. The characterisation methodology assuch was evaluated and different models were tested to find themost suitable. In addition, other properties such aselectrochemical stability and thermal properties were alsostudied.</p><p>In the study of electrochemical stability it wasdemonstrated that the electrode material influenced thevoltammetric results significantly. The most versatileelectrode for probing the electrolyte stability proved to beplatinum. The method was concluded to be suitable for comparingelectrolytes and the influences of electrolyte components,additives and impurities, which was also demonstrated for a setof liquid and polymer containing electrolytes.</p><p>A full set of transport properties for two binary polymerelectrolytes, one binary liquid and the corresponding ternarygel were achieved. The transport was studied both in the bulkand in porous electrodes, using different electrochemicaltechniques as well as Raman spectroscopy. In general, theconductivity, the salt and solvent diffusivity decreasedsignificantly when going from liquid to gel, and to polymerelectrolyte. Additionally, low cationic transport numbers wereachieved for the polymer and gel and significant salt activityfactor variations were found. The results were interpreted interms of molecular interactions. It was concluded that both theionic interactions and the influences from segmental mobilitywere significant for the polymer containing electrolytes. Thecharacterisation methods and the understanding were improved bythe use of a numerical modelling using a model based on theconcentrated electrolyte theory. It was concluded thatelectrochemical impedance spectroscopy and Raman spectroscopywere insufficient for determining a full set of transportproperties. It was demonstrated that the transport is veryinfluential on electrochemical impedance as well as batteryperformance.</p><p><b>Keywords:</b>lithium battery, electrolyte, mass transport,stability, modelling, characterisation, electrochemical, Ramanspectroscopy, impedance</p>

Das Ziel der vorliegenden Arbeit ist die bessere Verarbeitung von Polyanilin (PANI), da dies bisher ein großer Nachteil unter leitfähigen Polymeren war. Dazu wird ein sperriges Tensid und Dotand, Dodecylbenzensulfonsäure (DBSA) verwendet. Zur Synthese der PANI kommen zwei verschiedene Methoden zur Anwendung, die in dieser Dissertation in zwei Kapiteln beschrieben werden. Im ersten Teil wurden in einem kleinen Reaktionsvolumen (250 mL) PANI-DBSA-Suspensionen synthetisiert, wobei mit einem binären Gemisch aus 2-Propanol und Wasser als Lösungsmittel gearbeitet wird um die Löslichkeit zu unterstützen. Die micellenunterstützte Synthese produziert grüne Dispersionen, welche nach länger als einem Jahr noch keine sichtbare Ausscheidung zeigen. Eine detaillierte spectroelektrochemische Untersuchung der PANI-DBSA-Nanokolloide wurde durchgeführt und gibt eine bessere Erklärung der Charge-Transfer-Prozesse zwischen PANI-Kolloiden und Elektrodenoberfläche. In einem alkalischen Medium ist das UV-Vis-Spektrum von der Beweglichkeit der Anionen und von einem elektrokinetischen Phänomen abhängig. Um den „metal-to-insulator”-Übergang zwischen PANI-Kolloiden, welcher durch pH-Wert-Änderung des Mediums geschehen kann, zu zeigen, wurden UV-Vis- und pre-resonanz-Raman-Spektroskopie verwendet. Im zweiten Teil der Dissertation wird zur Polymerisation von Anilin sowie seinen Copolymeren mit o-Toluidin eine neue Technik der Polymerisation beschrieben, welche durch inverse Emulsion erfolgt. Diese benutzt Benzoylperoxid, ein ungewöhnlicheres organisches Oxidationsmittel. Die erhaltenen PANI sind in gebräuchlichen organischen Lösungsmitteln, wie in Chloroform, vollständig löslich. Mit einer klar-transparenten, grünen Lösung von PANI können metallische Oberflächen oder Glas leicht tropfenbeschichtet werden. Zyklische Voltammetrie und spektroelektrochemische Verfahren kamen zum Einsatz, um die Elektroaktivität, das UV-Vis-Verhalten und die „metal-to-insulator”-Übergänge der chemisch synthetisierten PANI als Funktion des verwendeten Elektrodenpotentials zu untersuchen. Die elektrische Leitfähigkeit der Materialien ist relativ hoch (R = 10 ). SEM-Untersuchungen zeigen, dass die Menge des zugesetzten DBSA die Morphologie des Polymers stark beeinflusst. Aus in situ UV-Vis-spektroskopischen Messungen lässt sich eine gute elektrochromische Reversibilität des Polymers erkennen. DBSA kann Poly(o-toluidin) (POT) effektiv dotieren, auch wenn von der Methylgruppe eine sterische Hinderung ausgeht. Die spektroskopischen Untersuchungen, wie UV-Vis, FT-IR, Raman-Spektroskopie und zyklische Voltammetrie, zeigen deutlich, dass wirkliche Copolymere gebildet werden und die Möglichkeit von Kompositen nicht in Betracht kommt. Das entstandene Poly(anilin-co-o-toluidin) (PAT) ist in schwach polaren Lösungsmitteln wie Chloroform löslich. Wie erwartet, sind die elektrischen Leitfähigkeiten der Copolymere viel kleiner als die Leitfähigkeit von PANI-DBSA.

Thesis (M. Phil.)--University of Hong Kong, 2001. / Includes bibliographical references (leaves 80-85).

Thesis (M. Phil.)--University of Hong Kong, 2001. / Includes bibliographical references (leaves 81-86).

Thesis (Ph. D.)--University of California, Riverside, 2009. / Includes abstract. Available via ProQuest Digital Dissertations. Title from first page of PDF file (viewed March 12, 2010). Includes bibliographical references (p. 96-107). Also issued in print.

Long range stand-off Raman and Laser-Induced Breakdown Spectroscopy (LIBS) lidar signal simulations have been carried out using a modified UV-visible atmospheric transmission program and a modified lidar equation. The Hitran-PC atmospheric transmission program which normally operates over the wavelength range of 400 nm to the far-IR was modified to provide UV atmospheric attenuation (200 nm -- 400 nm) using the optical cross section data contained in the HITRAN database. The two-way lidar equation was modified in order to simulate the one-way propagation of the Raman and LIBS spectral, and thus provide calculations of the expected Raman or LIBS signal as a function of range. Estimation of the LIBS and Raman spectral intensity was then calculated for several remote sensing cases. In particular, the atmospheric attenuation spectra generated with the modified Hitran-PC program were combined with the calculated LIBS and Raman lidar emission spectra at the remote excitation site using a modified lidar equation to determine for the first time to our knowledge the power and S/N ratio versus range of the LIBS and Raman Lidar complete spectrum as a function of wavelength in the UV -- IR region. Previous simulations had only made S/N versus range calculations at a single wavelength or for the total integrated emission. These results are important as they can be used for future design of stand-off LIBS and Raman lidar systems, and for comparisons with experimental measurements. In particular, we are planning to use our simulations for comparison of 266 nm excited LIBS and Raman lidar measurements of energetic compounds at ranges of a few tens of meters.

Continual scaling of devices and on-chip wiring has brought significant challenges for materials and processes beyond the 32-nm technology node in microelectronics. Recently, three-dimensional (3-D) integration with through-silicon vias (TSVs) has emerged as an effective solution to meet the future interconnect requirements. Among others, thermo-mechanical reliability is a key concern for the development of TSV structures used in die stacking as 3-D interconnects. In this dissertation, thermal stresses and interfacial reliability of TSV structures are analyzed by combining analytical and numerical models with experimental measurements. First, three-dimensional near-surface stress distribution is analyzed for a simplified TSV structure consisting of a single via embedded in a silicon (Si) wafer. A semi-analytic solution is developed and compared with finite element analysis (FEA). For further study, the effects of anisotropic elasticity in Si and metal plasticity in the via on the stress distribution and deformation are investigated. Next, by micro-Raman spectroscopy and bending beam technique, experimental measurements of the thermal stresses in TSV structures are conducted. The micro-Raman measurements characterize the local distribution of the near-surface stresses in Si around TSVs. On the other hand, the bending beam technique measures the average stress and viii deformation in the TSV structures. To understand the elastic and plastic behavior of TSVs, the microstructural evolution of the Cu vias is analyzed using focused ion beam (FIB) and electron backscattering diffraction (EBSD) techniques. To study the impacts of the thermal stresses on interfacial reliability of TSV structures, an analytical solution is developed for the steady-state energy release rate as the upper bound of the driving force for interfacial delamination. The effect of crack length and wafer thickness on the energy release rate is studied by FEA. Furthermore, to model interfacial crack nucleation, an analytical approach is developed by combining a shear lag model with a cohesive interface model. Finally, the effects of structural designs and the variation of the constituent materials on TSV reliability are investigated. The steady state solutions for the energy release rate are developed for various TSV designs and via materials (Al, Cu, Ni, and W) to evaluate the interfacial reliability. The parameters for TSV design optimization are discussed from the perspectives of interfacial reliability. / text