Confocal microscopy has been used as a tool for studying adsorption of biomolecules to individual chromatographic adsorbent particles. By coupling a fluorescent dye to protein molecules, their penetration into single adsorbent particles could be observed visually at different times during batch uptake. By relating the relative fluorescence intensity obtained at different times to the value at equilibrium, the degree of saturation versus time could be constructed. The use of two different fluorescent dyes for protein labeling and two independent detectors, allowed direct observation of a two-component adsorption process. The confocal technique was also applied for visualization of nucleic acids. Plasmid DNA and RNA were visualized with fluorescent probes that binds to double stranded DNA and RNA respectively. Confocal measurements following single component adsorption to ion exchange particles, revealed an interesting phenomenon. Under certain experimental conditions, development of "inner radial concentration rings" (i.e. adsorbed phase concentrations that are higher at certain radial positions within the particle) were observed. Some examples are given that show how such concentration rings are formed within a particle. Methods were also developed for measurement of the spatial distribution of immobilized functional groups. Confocal microscopy was used to investigate the immobilization of trypsin on porous glycidyl methacrylate beads. Artefacts relating to optical length differences could be reduced by use of "contrast matching". Confocal microscopy and confocal micro-Raman spectroscopy, were used to analyze the spatial distribution of IgG antibodies immobilized on BrCN-activated agarose beads. Both these measurement methods indicate an even ligand distribution. Finally, confocal Raman and fluorescence spectroscopy was applied for measurement of the spatial distribution of iminodiacetic- and sulphopropyl groups, using Nd3+ ions as fluorescent probes. Comparison of different microscope objectives showed that an immersion objective should be used for measurement of wet adsorbent particles. Direct experimental information from the interior of individual adsorbent particles will increase the scientific understanding of intraparticle mass transport and adsorption mechanisms, and is an essential step towards the ultimate understanding of the behaviour of chromatographic adsorbents.

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. 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. 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. 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. <b>Keywords:</b>lithium battery, electrolyte, mass transport,stability, modelling, characterisation, electrochemical, Ramanspectroscopy, impedance

In this thesis, volumetric, optical and vibrational properties of H2O were studied at high pressures by combining techniques of Raman spectroscopy, interferometry and optical imaging. Pressures up to 7 GPa were generated in the diamond anvil cell (DAC), entering the stability fields of liquid water and ices VI, VII and VIII. A new integrated system for Raman, interferometric and optical-imaging studies has been built up. Utilizing the interferometric patterns formed between closely-spaced diamond anvils, the system allowed the complete monitoring and control of pVT-conditions of studied ices, as well as the determination of their dispersive properties in the visible range using the Airy equation and Cauchy formulation. This setup and technique thus represent a novel tool for the precise determination of equations of state (EOSs) of transparent materials, including fluids and low-Z materials. Data-sets on thermal pressure were obtained from heating/cooling experiments carried out on the liquid water and used for checking the mutual consistency between published EOSs. A pVT-EOS for ice VIII and room temperature isotherms for ices VI and VII at 300 K were derived by combined methods of interferometry and imaging. While the agreement with the available EOSs of ices VII and VIII is very good, some inconsistent EOSs of ice VI were identified in the present study. The technique of micro-Raman spectroscopy was applied for the monitoring of phase transformations, identification of various ice phases and for studying the response of vibrational symmetry modes to varying conditions. Analysis based on the combination of the pT-dependencies of the vibrational frequencies with the pVT-EOSs showed that, in the studied ices, the implicit volume-driven contributions dominate over the explicit phonon effects in the total temperature-induced changes in vibrational frequencies. The results provide valuable insight on the anharmonic effects and interactions in these molecular solids.

AlₓGa₁₋ₓN (x>0.6) based Ultraviolet Light Emitting Diodes (UV LEDs) emit in the UV C range of 200 - 290 nm and suffer from low external quantum efficiencies (EQEs) of less than 3%. This low EQE is representative of a large number of non-radiative recombination events in the multiple quantum well (MQW) layers, which leads to high device temperatures due to self-heating at the device junction. Knowledge of the device temperature is essential to implement and evaluate appropriate thermal management techniques, in order to mitigate optical degradation and lifetime reduction due to thermal overstress. The micro-scale nature of these devices and the presence of large temperature gradients in the multilayered device structure merit the use of several indirect temperature measurement techniques to resolve device temperatures. This work will study UV LEDs with AlₓGa₁₋ₓN active layers, grown on sapphire or AlN growth substrates, and flip-chip mounted onto submounts and package configurations with different thermal properties. Thermal metrology results will be presented for devices with different electrode geometries (i.e., interdigitated and micropixel), for bulk and thinned growth substrates. The body of this work will present a comparative study of optical techniques such as Infrared (IR), micro-Raman and Electroluminescence (EL) spectroscopy for the thermal metrology of UV LEDs. The presence of horizontal and vertical temperature gradients within the device layers will be studied using micro-Raman spectroscopy, while the occurrence of thermal anomalies such as hotspots and shorting paths will be studied using IR spectroscopy. The Forward Voltage (Vf) method, an electrical junction temperature measurement technique, will also be investigated. The Vf method will be applied to the Thermal Resistance Analysis by Induced Transient (TRAIT) procedure, whereby electrical data at short time scales from an operational device will be used to discretize the junction-to- package thermal resistance pathway from the total junction- to-ambient heat path. The TRAIT procedure will be conducted on several LEDs, for comparison. The scope and applicability of each thermal metrology technique will be examined, and the merits and demerits of each technique will be exhibited.

Botryococcus braunii (Chlorophyta, Botryococcaceae) is a colony-forming green microalga that produces large amounts of liquid hydrocarbons, which can be converted into transportation fuels. While B. braunii has been well studied for the chemistry of the hydrocarbon production, very little is known about the molecular biology of B. braunii. As such, this study developed both apparatus and techniques to culture B. braunii for use in the genetic and biochemical characterization. During genetic studies, the genome size was determined of a representative strain of each of the three races of B. braunii, A, B, and L, that are distinguished based on the type of hydrocarbon each produces. Flow cytometry analysis indicates that the A race, Yamanaka strain, of B. braunii has a genome size of 166.0 +/- 0.4 Mb, which is similar to the B race, Berkeley strain, with a genome size of 166 +/- 2.2 Mb, while the L race, Songkla Nakarin strain, has a substantially larger genome size at 211.3 +/- 1.7 Mb. Phylogenetic analysis with the nuclear small subunit (18S) rRNA and actin genes were used to classify multiple strains of A, B, and L races. These analyses suggest that the evolutionary relationship between B. braunii races is correlated with the type of liquid hydrocarbon they produce. Biochemical studies of B. braunii primarily focused on the B race, because it uniquely produces large amounts of botryococcenes that can be used as a fuel for internal combustion engines. C30 botryococcene is metabolized by methylation to generate intermediates of C31, C32, C33, and C34. Raman spectroscopy was used to characterize the structure of botryococcenes. The spectral region from 1600?1700 cm^-1 showed v(C=C) stretching bands specific for botryococcenes. Distinct botryococcene Raman bands at 1640 and 1647 cm^-1 were assigned to the stretching of the C=C bond in the botryococcene branch and the exomethylene C=C bonds produced by the methylations, respectively. A Raman band at 1670 cm^-1 was assigned to the backbone C=C bond stretching. Finally, confocal Raman microspectroscopy was used to map the presence and location of methylated botryococcenes within a living colony of B. braunii cells.

Plasmonic nanoparticles and their assembly have the potential to serve as a platform in practical applications such as photonics, sensing, and nano-medicine. To use plasmonic nanoparticles in these applications, it is important to understand their optical properties and find methods to control their optical response. Using polarization-sensitive dark-field spectroscopy to study self-assembled nanoparticle rings on substrates with different permittivities I show that the interaction between collective plasmon resonances and the substrate can control the spatial scattering image. Using liquid crystals as an active medium that can be controlled with an external electric field I show that the Fano resonance of an asymmetric plasmonic assembly can be actively controlled utilizing the polarization change of scattered light passing through the liquid crystal device. Furthermore, utilizing the strong electromagnetic field enhancement of coupled plasmonic “nanospikes” on the surface of gold nanoshells with a silica core, I show the use of single spiky nanoshells as surface-enhanced Raman spectroscopy substrates. Individual spiky nanoshells give surprisingly reproducible surface-enhanced Raman spectroscopy intensities with a low standard deviation compared to clusters of nanoparticles. In summary, the work presented here provides understanding of the plasmonic response for assembled nanoparticles on different substrates, illustrated a new method to actively control the optical response of plasmonic nanoparticles, and characterizes spiky nanoshells as surface-enhanced Raman scattering platform.

Ion irradiation of carbon nanotubes is a tool that can be used to achieve modification of the structure. Irradiation stability of carbon nanotubes was studied by ion and electron bombardment of the samples. Different ion species at various energies were used in experiments, and several defect characterization techniques were applied to characterize the damage. Development of dimensional changes of carbon nanotubes in microscopes operated at accelerating voltages of 30 keV revealed that binding energy of carbon atoms in CNs is much lower than in bulk materials. Resistivity measurements during irradiation demonstrated existence of a quasi state of defect creation. Linear relationship between ID/IG ratio and increasing irradiation fluence was revealed by Raman spectroscopy study of irradiated carbon buckypapers. The deviations from linear relationship were observed for the samples irradiated to very high fluence values. Annealing of irradiated samples was able to reduce the value of ID/IG ratio and remove defects. However, annealing could not affect ID/IG ratio and remove defects in amorphized samples. The extracted value of activation energy for irradiated sample was 0.36 ±0.05 eV. The value of activation energy was in good agreement with theoretical studies.

Research in nanoparticle-reinforced composites is predicated by the promise for exceptional properties. However, to date the performance of nanocomposites has not reached its potential due to processing challenges such as inadequate dispersion and patterning of nanoparticles, and poor bonding and weak interfaces. The main objective of this dissertation is to improve the physical properties of polymer nanocomposites at low nanoparticle loading. The first step towards improving the physical properties is to achieve a good homogenous dispersion of carbon nanofibers (CNFs) and single wall carbon nanotubes (SWNTs) in the polymer matrix; the second step is to manipulate the well-dispersed CNFs and SWNTs in polymers by using an AC electric field. Different techniques are explored to achieve homogenous dispersion of CNFs and SWNTs in three polymer matrices (epoxy, polyimide and acrylate) without detrimentally affecting the nanoparticle morphology. The three main factors that influence CNF and SWNT dispersion are: use of solvent, sonication time, and type of mixing. Once a dispersion procedure is optimized for each polymer system, the study moves to the next step. Low concentrations of well dispersed CNFs and SWNTs are successfully manipulated by means of an AC electric field in acrylate and epoxy polymer solutions. To monitor the change in microstructure, alignment is observed under an optical microscope, which identifies a two-step process: rotation of CNFs and SWNTs in the direction of electric field and chaining of CNFs and SWNTs. In the final step, the aligned microstructure is preserved by curing the polymer medium, either thermally (epoxy) or chemically (acrylate). The conductivity and dielectric constant in the parallel and perpendicular direction increased with increase in alignment frequency. The values in the parallel direction are greater than the values in the perpendicular direction and anisotropy in conductivity increased with increase in AC electric field frequency. There is an 11 orders magnitude increase in electrical conductivity of 0.1 wt% CNF-epoxy nanocomposite that is aligned at 100 V/mm and 1 kHz frequency for 90 minutes. Electric field magnitude, frequency and time are tuned to improve and achieve desired physical properties at very low nanoparticle loadings.

A nanofluidic biosensor using surface-enhanced Raman scattering (SERS) was developed to detect the β-amyloid (Aβ) protein, one of the biomarkers of Alzheimer’s disease (AD). Recent studies have indicated that investigating changes in relative concentrations of structure specific Aβ oligomers in cerebral spinal fluid (CSF) during the progression of AD could be important indicators for diagnosing AD pre-mortem. However, there is no definitive pre-mortem diagnosis of AD thus far because of the lack of technology available for sensitive Aβ detection. Hence, the development of a system for detecting the structure specific Aβ oligomers, along with the concentrations of these oligomers in CSF, would be useful in the investigation of the molecular mechanisms of Aβ cytotoxicity associated with AD. In this thesis, a nanofluidic trapping device trapping system for detecting biomolecules at sub-picomolar concentrations was developed for using SERS. The device, with a microchannel leading to a nanochannel, carries out dual functions: encouraging sizedependent trapping of gold nanoparticles (60nm) at the entrance of the nanochannel as well as restricting the target molecules between the gaps created by the aggregated nanoparticles. Initially, the trapping capability of the nanofluidic device was tested using fluorescent polystyrene and gold nanoparticles. UV-vis absorption spectroscopy was used to characterize the gold nanoparticle clusters at the entrance to the nanochannel. The device established controlled, reproducible, SERS active sites within the interstices of gold nanoparticle clusters and shifted the plasmon resonance to the near infrared, in resonance with incident laser light. Two strongly Raman active molecules, adenine and Congo red, were used to test the feasibility of the SERS nanofluidic device as a platform for the detection of multiple analytes. The results showed that strong SERS signals were obtained from the nanoparticle clusters at the nanochannel entrance. Once the feasibility of the approach was determined with strong Raman molecules, Aβ was detected using this nanofluidic SERS platform. Distinct surface-enhanced Raman spectra of Aβ was observed in different conformational states as a function of concentration and structure (monomer versus oligomer form) due to Aβ refolding from α-helical to a predominantly β-pleated sheet form. The sensor was also shown to potentially distinguish Aβ from insulin and albumin, confounder proteins in cerebral spinal fluid. Thus, a novel platform was developed to detect picomoler levels of Aβ with the ultimate goal of facilitating the diagnosis and understanding of Alzheimer’s disease by means of detecting structure specific oligomers of Aβ.

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.