Green liquor dreg (GLD) is a residual product that could be a solution to the problem with acid rock drainage. More information about how this material reacts and is affected when in contact with acid rock drainage (ARD) is needed. Different acidic media was used to investigate trace element leaching and the possible spectral changes using FTIR. It was possible to detect changes between samples based on the exposure for different acidic conditions. Most peaks were found below 1 500 cm-1 which complicates the interpretation. For enabling the use of multivariate analysis the spectral data needed to be pre-treated and after this it was possible to see groupings and directions based on exposure. Different tendencies are seen for the trace elements, where some element leaching increased at lower pH and some elements decreased leaching at lower pH. This could partly be due to the formation of salts with low solubility such as gypsum and anglesite when leached with sulphuric acid.

Deeper understanding and technological progress in materials physics demand exploration of soft and hard matter at their relevant length scales. This research focuses on the nanometer length scale investigation of structural changes required for membrane fusion in virus nanoparticles and nano-spectroscopic investigation of layered material surfaces implementing scattering type scanning near-field optical microscopy (s-SNOM). Spectroscopy and imaging experiments were deployed to investigate the chemical and structural modifications of the viral protein and lipid bilayer under various environmental pH variations. It has been shown that breakage of viral membrane could occur even without the presence of a targeting membrane, if the environment pH is lowered. This is in contrary to the current viral fusion model, which requires virus binding to a host cell membrane for forming the fusion pore to release the viral genome. The fusion inhibitor compound 136 can effectively prevent the membrane breakage induced by low pH. The chemical surface stability and degradation of black phosphorus (BP) under ambient conditions have been studied using s-SNOM. We found that the degraded area and volume on the surface of black phosphorus increase with time slowly at the start of degradation and enlarge rapidly (roughly exponentially) afterward and reach saturation growth following S-shaped growth curve (sigmoid growth curve). The theoretical model presented suggests that the degraded sites in the adjacent surrounding causes the experimentally observed exponential growth of degraded area at the initial stage. By studying the BP surfaces coated by Al2O3, boron nitride (BN) and hybrid BN/Al2O3 layers through the period up to 6 months, it has been concluded that ~5 nm thin hybrid layer of BN/Al2O3 helps the surface passivation of BP flakes of thickness ~30 nm. This is supported by the electrical characterization results of BP field effect transistor coated with a BN/Al2O3 layer. We have performed infrared nano-spectroscopy on muscovite mica exfoliated on silicon and silicon dioxide substrates. We show that the near-field profile in s-SNOM can penetrate down to several hundreds of nanometers and enable spectroscopy of buried structures. We found spectral broadening of mica as its thickness increases revealing clearly the effect of size on the absorption response.

L’insuffisance rénale chronique (IRC) et l’une des pires maladies chroniques dans les pays développés. Les grades de l’IRC sont principalement basés sur la mesure ou l’estimation du taux de filtration rénale (GFR). Cependant, cette méthode est peu sensible sur les premiers stades de la pathologie et n’apporte donc pas de valeur diagnostique. La détection de la pathologie à des stades précoces et son traitement peuvent éviter ou limiter les effets délétères de la chronicité. Cette thèse se penche sur le développement de la microscopie IRTF en tant qu’outil diagnostic pour l’identification par histopathologie à l’échelle du glomérule dans un modèle d’IRC. Nous avons développé la technique de reconstruction 3D pour l’imagerie IRTF des modifications biochimiques à l’échelle du glomérule pour déterminer des marqueurs de l’IRC. La déconvolution spectrale et le clustering sont appliqués après analyses IRTF pour distinguer les modèles sains et pathologiques. Ensuite, la microvasculature glomérulaire est révélée par agent de contraste pour en déterminer les anomalies morphologiques. Grâce aux résultats obtenus en 3D et l’utilisation de méthodes statistiques avancées, la microscopie IRTF est utilisée comme une technique fonctionnelle pour déterminer les modifications morphologiques et moléculaires apparaissant au cours du développement de l’IRC. / CKD (Chronic Kidney Disease) is one of the worst public diseases in developing countries. The stages of CKD are mainly based on measured or estimated GFR (Glomerular Filtration Rate). However, this method is not sensitive enough on early stages of the pathology and thus do not offer accurate diagnostic value. Early detection and treatment can often limit or avoid the chronicity effects of the disease. This thesis focuses on the development of FTIR microscopy as a diagnostic tool for the identification by histopathology at glomerulus level of the kidney in CKD model. We developed a technique of 3D reconstruction for the FTIR imaging of biochemical components changes in glomeruli for identifying the pathological marker of CKD. The curve-fitting and spectral clustering are applied on the FTIR microscopy analysis to distinguish between healthy and pathological glomeruli of a kidney. Then, the glomerular microvasculatureis highlighted to reveal the morphological abnormalities by perfusing contrast agents into blood vessels. With advanced 3D statistical methods and 3D image visualization by microscopy, FTIR spectro-imaging can be used as a functional technique to determine the morphological and molecular changes occurring along CKD development.

Overhead conductors used in the transmission of power in grids around the world are generally subjected to ageing, which is the time-based change of their properties. Important properties such as corona discharge, audible noise, hydrophobicity and corrosion are usually considered and investigated. On some conductors such as the aluminium conductor steel reinforced (ACSR), a reduction in audible noise over exposure time to the service environment has been noted to occur. However, the converse has been observed for the gap-type thermal resistant aluminium conductor steel reinforced (GTACSR or “Matthew” conductor), although this conductor is preferred due to its high ampacity. The relationship between conductor hydrophobicity, audible noise, surface contamination and roughness, wettability and corrosion were investigated using All Aluminium Alloy Conductor (AAAC), Aluminium Conductor Composite Core (ACCC) and GTACSR samples. Findings from Fourier Transform Infrared Spectroscopy (FTIR), X-ray Photoelectric Spectroscopy (XPS) and contact angle measurements revealed that carbon, hydrocarbon and silicone contamination was responsible for the hydrophobic nature of the surface. Furthermore, electrochemical investigations and electron microscopy showed that pitting or/and crevice corrosion were the predominant corrosion mechanisms on these conductors. Exposure to simulated industrial and marine environments further confirmed this finding and also showed that general corrosion also occurs on relatively uncontaminated conductors, thereby changing their surface roughness, as seen from the White Light Interferometry results. Corrosion was observed to be accelerated by the presence of surface contaminants such as oils and carbon, as these facilitated water (droplet) retention by reducing the conductor’s surface energy. Reduction/elimination of surface contamination/hydrophobicity were the desired solutions to the problem, and this was achieved by grit blasting. Partial/complete oxidation of the silicones resulted in the reduction/elimination of sample hydrophobicity – this was seen from more contact angles measurements and XPS data. Grit blasting also restored conductor cleanliness and roughened the surface sufficiently to produce surface run-off.

Absorption of octadecanethiol and p-nitrobenzenethiol onto gold surfaces from ethanol solutions has been studied by means of contact angle, optical ellipsometry, angle-resolved XPS (ARXPS), and with grazing angle total reflection FTIR. Growth of the monolayers from dilute solutions has been monitored and Langmuir isotherm adsorption curves were fitted to experimental data. A saturated film is formed within approximately 5h after immersion in solutions of concentrations ranging from 0.0005mM to 0.01mM. We found, that the final density of monolayer depends on the concentration of the solution.

Esta tesis se enmarca en el programa de doctorado realizado por convenio entre la Facultad de Ingeniería de la UNIMET (Caracas) y el Departamento de Proyectos de Ingeniería de la Universidad Politécnica de Valencia. La investigación que se ha planteado consiste en el desarrollo de una metodología predictiva del cumplimiento de requisitos funcionales de los aceites empleados en aviación, con el objetivo de sustituir los actuales análisis fisicoquímicos de los aceites en servicio (que permiten determinar la degradación u oxidación de los aceites mencionados) por modelos estadísticos que parten de la información obtenida por espectroscopia de infrarrojo (FTIR). Se han realizado análisis por FTIR de 4 tipos de aceite (aceites minerales usados, aceites minerales envejecidos en laboratorio, aceites sintéticos usados y aceites sintéticos envejecidos en laboratorio) y aplicado modelos de regresión multivariante para poder predecir la acidez (uno de los principales indicadores de desgaste) de los aceites. De esta forma es posible realizar de manera más rápida y más económica (sin consumo de reactivos) los ensayos que necesitan las aeronaves privadas en Venezuela (y las correspondientes regulaciones de los diferentes países) para mantener el certificado de aeronavegabilidad. El analizar aceites envejecidos en condiciones controladas de laboratorio tiene como interés conocer cómo afecta el tiempo y la temperatura a cada tipo de aceite de manera que pueda garantizarse el perfil FTIR de los aceites usados en condiciones reales. En los modelos elaborados para mejorar la capacidad de predicción de la acidez de los aceites, se ha trabajado especialmente la localización de los rangos del espectro en los que aparecen los principales compuestos de degradación / Leal De Rivas, BC. (2014). Metodología para la caracterización de aceites usados en aviación basada en técnicas espectroscópicas [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/48468 / TESIS

This master’s thesis deals with the plasmon resonance of the nanostructures of several selected tungsten oxides using Fourier transform infrared spectroscopy (FTIR spectroscopy). The physical principles of the plasmonics, the characteristics of the materials used, as well as the principle of operating and measuring on the FTIR spectrometer, are described in the first part of this thesis. The second part is focused on the preparation of samples and performing measurements on the FTIR spectrometer. This part ends by representing the final spectra and the results obtained.

The functional and pathogenic roles of biomolecules are often coupled to the self-association of their basic units into oligomers and aggregates whose structural details are difficult to distinguish because of their insoluble and heterogenous nature. This work focuses on DNA G-quadruplex motifs and amyloid peptides whose oligomers and aggregates are associated with numerous biological roles and human diseases. Infrared (IR) spectroscopy is a powerful tool which probes vibrational transitions whose signatures report on their arrangement within molecules. Advances in two-dimensional infrared (2D IR) spectroscopy have allowed structural characterization in increasingly complex biomolecules that are not amenable to traditional high-resolution techniques. However, careful consideration of the physical phenomena that lead to IR spectra are necessary to make accurate assignments. In the first portion of this work, using FTIR and 2D IR, we determine spectral markers that can differentiate size, metal ion coordination, and topology in DNA G-quadruplex motifs. IR studies aided by isotope labeling define the physical origin of these markers and allow for the construction of a structural landscape in parallel DNA G-quadruplex motifs. It is also shown that 2D IR and isotope editing probes site-specific structural changes in G-quadruplex motifs that can differentiate ion identity and location based on spectral shifts. In the latter portion of this work, we use a combination of spectroscopy and imaging techniques to show that a peptide derived from the human pro-apoptotic protein BAX forms amyloid aggregates whose structure is dependent on the presence of model membranes. Combined, the work in this thesis allows for the formulation of multiple hypotheses based on IR structural assignments regarding disease states and functional mechanisms of these systems.

Amyloid aggregation involves the spontaneous formation of fibers from misfolded proteins. This process requires low energy input, results in robust fibers, and is thus of interest from a materials manufacturing perspective. The effect of glutamine content and hydrophobicity of template peptides on amyloid aggregation of a template-peptide system involving myoglobin was studied at near-physiological conditions by Fourier transform infrared spectroscopy, atomic force microscopy, field emission scanning electron microscopy, and nanoindentation. Hydrophobic interactions were found to be important for controlled hierarchical fiber growth via a cooperative mechanism, with the largest effect in myoglobin mixtures. Hydrophobic packing increased for most systems as aggregation progressed. The largest changes in structure occurred upon drying. When myoglobin was present with the highest glutamine-containing template (P7), the high glutamine peptide was not effective as a template, since it appeared to prefer self-catalysis. A low level of glutamine in some unordered templates was insufficient for amyloid development. However, templating was more important in glutamine-free templates mixed with myoglobin, which formed fibers with a surprisingly high elastic modulus. This may have been due to template patterning. Nanoindentation results confirmed that glutamine blocks were not necessary for strong intermolecular interactions and cooperative fibril formation. / Master of Science

Thesis advisor: Matthias M. Waegele / Studying the adsorption and reaction kinetics of surface-bound chemical species, on different metal catalysts or electrodes, is of paramount importance in the development of inhomogeneous catalytic methodology. Our study of the oxidation of CO on platinum was accomplished by designing a thin layer flow cell in an external reflection configuration. A charge-injection circuit was successfully implemented which decreased the time required to charge the double layer in the electrochemical cell. We were able to obtain a signal via Stark shift spectrum, of the adsorbed CO, using the thin layer cell configuration. Additionally, electrochemical impedance spectroscopy was used as a diagnostic tool to assess the effect of electrode geometry, on the voltage response, in the thin layer cell. The coupling of visible light-driven photoexciation with transition metal catalytic plat- forms is emerging as a synthetic strategy to achieve unique reactivity that has previously been inaccessible. One such example is the iridium/nickel-dipyridyl system discovered recently. Characterizing the interactions between the iridium and nickel catalysts, under reaction conditions, is important to develop a better understanding of the system. In order to apply infrared spectroscopic measurement techniques, in-situ, we made modifications to the synthetic scheme by changing the solvent and by utilizing different iridium catalysts for the synthesis of the desired methyl 4-(benzoyloxy)benzoate product. Using our trans- mission infrared setup we effectively demonstrated in-situ product detection of the aryl- ester coupled product. Additionally, after constructing a transient infrared pump-probe setup, we collected preliminary results of the triplet state lifetime of the iridium dye. The surface morphology of copper has been shown to affect the electrochemical reduction of CO2. Using surface-enhanced Raman spectroscopies, the reversible formation of nanoscale metal clusters on a copper electrode was revealed at sufficiently cathodic potentials where we observed the appearance of a new band at 2080 cm-1 corresponding to C≡O adsorbed to undercoordinated copper defect sites. The formation of new undercoordinated sites additionally resulted in the surface enhancement of the Raman scattering which amplified the intensity of the other spectral bands. / Thesis (MS) — Boston College, 2019. / Submitted to: Boston College. Graduate School of Arts and Sciences. / Discipline: Chemistry.