The solvent-solute interface of a biomolecule is a dynamic but yet highly structured domain that links a chemically diverse solute surface to the chemically homogeneous bulk aqueous phase. The role of the resulting intermediate domain, i.e. the "hydration shell", in regulating DNA structure and recognition has been addressed here by time-resolved infrared spectroscopy. A highly reproducible automated hydration pulse regime was established and implemented for attenuated total reflectance (ATR) Fourier transform infrared (FTIR) spectroscopy to monitor the structural response of DNA to an incremental growth of its hydration shell on its intrinsic time scale of seconds. The transition from the crystallographically defined BI to the BII substate of B-DNA was found to be driven by the increase of water disorder upon growth of the hydration shell, derived from the water OH-stretching absorption frequency and band width changes. 2D correlation analysis was used to identify different water clusters from the temporal behaviour of their water OH stretching frequencies. The results show that BII-stabilizing structural constraints are exerted by strong water-DNA H-bonds in the grooves of B-DNA and are relieved when the groove-bound water merges into a contiguous hydration shell with the less H-bonded PO2- -solvation sphere at ~14 water molecules per DNA phosphate. The H-bond imbalance at the disjunct hydration sites is split symmetrically around the average H-bond strength of bulk water. Thus, merging into a contiguous hydration shell proceeds at little enthalpic cost and homogeneous connectivity to the outer bulk-like H-bond network, such that alteration in the network distant from the DNA can regulate the BI-BII transition in a cooperative manner. The water connectivity is disrupted by DNA-binding peptides. Remarkably, the data show that the replacement of hydration shell water upon ligand biding is crucial in conferring substate specific recognition by peptides that have little intrinsic structural preference. The antibacterial peptide indolicidin secreted from bovine neutrophils dehydrates the non-PO2--bound hydration sites, thereby rendering the unstructured peptide highly specific for the BI state with vibrational signature almost identical to the bacterial minor groove binder netropsin. The proposed dominant role of hydration shell water for DNA conformation was challenged by studying the competing effect of structured water in the coordination-shell of the lanthanide Eu3+ on water structure in the DNA hydration shell. Whereas no effect is seen at low hydration, a hydrogen-like phase is formed at a stoichiometric ratio of Eu3+ :DNA:H2O of 1:10:140, characterized by a strong increase of the molar volume of hydration water. This novel phase appears attractive for lanthanide and possibly actine separation approaches based on biomolecular coordination.

This work reports the elucidation of the structure of a copolymer generated by the cross- catalyzed reactions of PF and pMDI prepolymers.  The electronic behavior of phenolic monomers as perturbed by alkali metal hydroxides in an aqueous environment was studied with 1H and 13C NMR.  Changes in electronic structure and thus reactivity were related to solvated ionic radius, solvent dielectric constant, and their effect on ion generated electric field strength. NMR chemical shifts were used to predict order of reactivity for phenolic model compounds with phenyl isocyanate with good success.  As predicted, 2-HMP hydroxymethyl groups were more reactive than 4-HMP in forming urethane bonds under neutral conditions and 2-HMP hydroxymethyl groups were more reactive than 4-HMP in forming urethane bonds under alkaline conditions. The structure of the reaction products of phenol, benzyl alcohol, 2-HMP, and 4-HMP with phenyl isocyanate were studied using 1H and 13C NMR under neutral organic and aqueous alkaline conditions.  Reactions in THF-d8 under neutral conditions, without catalyst, were relatively slow, resulting in residual monomer and the precipitation of 1,3-diphenyl urea from the carbamic acid reaction.  The reactions of phenol, 2-HMP, and 4-HMP in the presence of TEA catalyst favored the formation of phenyl urethanes (PU). Reactions with benzyl alcohol, 2-HMP, and 4-HMP in the presence of DBTL catalyst favored the formation of benzyl urethanes (BU).  Reactions of 2-HMP and 4-HMP led to formation of benzylphenyldiurethane (BPDU).  DBTL catalysts favored formation of BDPU strictly by a benzyl urethane pathway, while TEA favored its formation mostly via phenyl urethane, although some BU was also present.  Under aqueous alkaline conditions, 2-HMP was more reactive than 4-HMP, exhibiting an enhanced reactivity that was attributed to intramolecular hydrogen bonding and a resulting resonance stabilization of the phenolic aromatic ring. ATR-FTIR spectroscopic studies generated real time structural information for model compound reactions of the cross-catalyzed system, differentiating among reaction peaks generated by the carbamic acid reaction, PU and BU formation.  ATR-FTIR also permitted monitoring of propylene carbonate hydrolysis and accelerated alkaline PF resole condensation.  ATR-FTIR data also showed that the overall reaction stoichiometry between the PF and pMDI components drove copolymer formation.  Benzyl urethane formation predominated under balanced stoichiometric conditions in the presence of ammonium hydroxide, while phenyl urethane formation was favored in its absence.  Accelerated phenolic methylene bridge formation became more important when the PF component was in excess in the presence of sufficient accelerator.  A high percentage of free isocyanate was present in solid copolymer formed at ambient temperature. The combination of ammonium hydroxide and tin (II) chloride synergistically enhanced the reactivity of the materials, reducing the residual isocyanate. From 13C CP/MAS NMR of the copolymer, the presence of ammonium hydroxide and tin (II) chloride and the higher PF concentration resulted in substantial urethane formation.  Ammonium hydroxide favored formation of benzyl urethane from the 2-hydroxymethyl groups, while phenyl urethane formed in its absence.  The low alkalinity PF resole with ammonium hydroxide favored benzyl urethane formation.  Comparison of these results with the 13C NMR model compound reactions with phenyl isocyanate under alkaline conditions confirmed high and low alkalinity should favor phenyl and benzyl urethane formation respectively.  These cross catalyzed systems are tunable by formulation for type of co-polymer linkages, reactivity, and cost. / Ph. D.

Die Ablagerung von Siliziumdioxid ist ein verbreitetes Phänomen, das mit der Toleranz von Pflanzen gegenüber Belastungen korreliert. Die Pflanzen akkumulieren das amorphe Siliziumdioxid in mikroskopischen Partikeln, den Phytolithen, jedoch ist der exakte Mechanismus nicht vollständig aufgeklärt. Um ein besseres Verständnis über die Ablagerung von Siliziumdioxid zu erlangen, wurden verschiedene spektroskopische Techniken an Sorghumblättern und molekularen Modellen angewandt. Festkörper Kernspinresonanz und thermogravimetrische Analysen zeigen, dass die Siliziumdioxidstruktur von der Phytolithe-Extraktion abhängt. Basierend auf Raman- und IR-Daten einzelner Phytolithe lassen sich die Änderungen dieser Strukturen ermitteln. Das deutet auf unterschiedliche biologische Prozesse der Ablagerung des Siliciumdioxids hin. Die Pflanzengewebe in denen Siliciumdioxid abgelagert ist, wurden mit einem multimodalen Ansatz charakterisiert, welcher Fluoreszenz-, Hellfeld- und Rasterelektronenmikroskopie beinhaltet. Die chemische Zusammensetzung der Pflanzengewebe wurden mit Raman- und FTIR-Mikrospektroskopie kartiert. Ein neuartiger Ansatz zur Untersuchung von Pflanzengeweben wurde verwendet, basierend auf der optischen Nahfeldmikroskopie im mittleren IR-Bereich. Dieser ermöglicht eine kombinierte Analyse von mechanischen Materialeigenschaften sowie der chemischen Zusammensetzung und Struktur. Um die Rolle der organischen Matrix zu verstehen, wurden Modellverbindungen betrachtet, die die Ablagerung von Kieselsäure in den Pflanzen induzieren können. In-vitro-Reaktionen konnten eine gleichzeitige Präzipitation von Lignin und Siliciumdioxid sowie eine Polymerisation zusammen mit Peptiden simulieren. Die Ergebnisse lassen starke Wechselwirkungen zwischen diesen Verbindungen vermuten. Neben einem besseren Verständnis verschiedener Aspekte der Silifizierung von Pflanzen werden in dieser Arbeit neue Methoden zur Charakterisierung von Pflanzenproben vorgeschlagen. / Silica deposition is a common phenomenon that correlates with plant tolerance to various stresses. Plants accumulate amorphous silica in microscopic particles termed phytoliths, through yet unclear mechanisms. With the aim to gain better understanding of the processes that govern silica deposition, different vibrational techniques were used on sorghum leaves and molecular models to obtain chemical and structural information addressing different length scales. Solid-state Nuclear Magnetic Resonance and thermogravimetric analysis showed that phytolith extraction methods affect silica structure. Nevertheless, Raman and IR analysis of individual phytoliths revealed differences in the structure and composition between phytolith types, suggesting the existence of different biological pathways for silica deposition. The environment of sorghum tissues where silica is deposited was assessed using a multimodal approach consisting of fluorescence, brightfield and scanning electron microscopies, while chemical composition was mapped using Raman and Fourier transformed Infrared microspectroscopy. Scattering-type near-field optical microscopy in the mid-infrared region was used to characterize the plant tissues, in both fixed and native plant samples. The nano-IR images and the mechanical phase image enabled a combined probing of mechanical material properties together with the chemical composition and structure of both the cell walls and the phytolith structures. In vitro reactions simulating lignin-silica co-precipitation and silica polymerization with peptides revealed strong interaction between these compounds and silica, and their possible involvement in silica deposition in the plant. This thesis provides a better understanding of the chemical process that control plant silicification, suggests new methodologies to characterize plant samples, and evaluates the current methods used in plant science.

Det är allmänt känt att stora mängder kemikalier används i textilindustrin och även om det är att föredra att återanvända och återvinna textil kommer oönskade kemikalier stanna kvar i det cirkulära kretsloppet. Vid sortering av textil behöver de varor med giftiga, miljö- och hälsofarliga ämnen sorteras bort och uteslutas ur kretsloppet. Det finns ännu ingen icke destruktiv portabel metod utvecklad för att skilja på textil med respektive utan farliga kemikalier. I det här arbetet har analysmetoderna Fourier transform infrarödspektroskopi (FTIR) och röntgenfluorescensdetektion (XRF) undersökts för möjlighet till användning i en sorteringsprocess. Testerna som utfördes var oförstörande tester, utan provberedning, på textila prover. Obehandlade samt färgade respektive fluorkarbonbelagda prover testades. I analyserna av testresultaten jämförs de behandlade proverna med de obehandlade. De testade proverna har också matchats mot två olika befintliga generella materialbibliotek, för att identifiera provets materialinnehåll. Ett materialbibliotek uppfördes med alla de textila material som testats. Mot detta bibliotek matchades ett antal använda klädesplagg med syfte att undersöka potentialen för ett textilanpassat materialbibliotek. FTIR-tester utfördes på ett stationärt instrument medan det för XRF användes ett portabelt instrument, dock finns båda teknikerna att tillgå som handhållna, portabla instrument. Testresultaten visar att XRF inte kan detektera textila fibrer men kan detektera kemikalier innehållande vissa tyngre grundämnen. Däremot gick det inte i testerna att indikera svavelinnehåll i ullproverna, vilket hade förväntats på förhand. Testerna med FTIR visade att det går att skilja på de vanligaste fibrerna inom fiberklasserna cellulosa, protein och syntet; bomull, ull och polyester. Däremot går det inte att skilja olika cellulosafibrer från varandra, vilket även inkluderar regenererade fibrer. Polyamid och polyester är mycket olika och går att skilja åt, dock är polyamid svår att skilja från silke och ull då deras kemiska struktur är mycket lika varandra. I undersökningarna gick det inte att se någon skillnad mellan de färgade proverna och deras respektive referensprov, inte heller gick det att skilja det fluorkarbonbelagda provet från ett obelagt. Matchningarna av de använda kläderna mot det textila materialbiblioteket visade goda resultat då majoriteten av plaggen matchades mot önskat material.

Self-assembly of colloidal microparticles is one of the strategies for making characteristic patterns. These versatile self-assemblies provide a route to elevate the efficiency of an electronic device. Silsesquioxane particles with various functionalities were synthesized by a modified Stöber condensation method. This thesis describes the synthesis of benzylchloride silsesquioxanes, benzylchloride-amine silsesquioxanes and amine-functionalized silsesquioxane particles with multi-fluorescent tags. The size and morphology of the particles were controlled by varying the concentration of base and anhydrous ethanol (solvent). The size distribution of particles was controlled by adjusting the molar ratios of organotrialkoxy silane, base, and ethanol concentrations. Through selective post-functionalization with fused arenes of anthracene and rhodamine, multifluorescent particles were obtained. Morphologies and optical properties of particles were characterized by TEM, SEM, fluorescence optical microscopy, and absorption and fluorescence spectroscopies. The composition of silsesquioxanes was confirmed by FTIR, thermogravimetric analysis, and elemental analysis. A versatile technique was developed for the self-assembly of particles on different polymer substrates by changing the colloidal suspension concentration and the polymer substrate.

Cleaning validation, in which cleaned surfaces are analysed for residual material, is an important process in pharmaceutical manufacturing and research facilities. Current procedures usually consist of either swab or rinse-water sampling followed by analysis of the samples. The analysis step is typically either rapid but unselective (conductivity, pH, total organic carbon, etc.), or selective but time-consuming (HPLC). This thesis describes the development of an in situ surface-spectroscopic analysis that removes the need for swab sampling and is both rapid and selective. This method has the potential to complement existing analyses to increase the efficiency of cleaning-validation protocols. The spectrometric system consists of a Fourier-transform infrared (FTIR) spectrometer coupled to a fibre-optic grazing-angle reflectance probe, and allows the measurement of infrared reflection-absorbance spectra (IRRAS) from flat surfaces in ~10 s. Multivariate chemometric methods, such as partial least squares (PLS) regression, are used to exploit the high information content of infrared spectra to obtain selective analyses without physical separation of the analyte or analytes from whatever interfering species may be present. Multivariate chemometric models require considerably more effort for calibration and validation than do traditional univariate techniques. This thesis details suitable methods for preparing calibration standards by aerosol deposition, optimising and validating the model by cross- and test-set validation, and estimating the uncertainty by resampling and formula-based approaches. Successful calibration models were demonstrated for residues of acetaminophen, a model active pharmaceutical ingredient (API), on glass surfaces. The root-mean-square error of prediction (RMSEP) was ~0.07 µg cm⁻². Simultaneous calibration for acetaminophen and aspirin, another API, gave a similar RMSEP of 0.06 µg cm⁻² for both compounds, demonstrating the selectivity of the method. These values correspond to detection limits of ~0.2 µg cm⁻², well below the accepted visual detection limit of ~1-4 µg cm⁻². The sensitivity of the method with a stainless steel substrate was found to depend strongly on the surface finish, with highly polished surfaces giving more intense IRRAS. RMSEP values of 0.04- 0.05 µg cm⁻² were obtained for acetaminophen on stainless steel with three different finishes. For this system, severe nonlinearity was encountered for loadings 1.0 µg cm⁻². From the results presented in this thesis, it is clear that IRRAS has potential utility in cleaning validation as a complement to traditional techniques.

Economic utilisation of biogas arising from sewage sludge is hampered by the need to remove siloxanes, which damage gas engines upon combustion. This thesis applies on-line Fourier transform infrared spectroscopy to measure siloxanes in biogas upstream and downstream of the activated carbon vessels designed to adsorb siloxanes. On-line analysis provides accurate measurement of siloxane concentrations with a detection limit below the siloxane limits set by engine manufacturers, high data intensity and timely identification of breakthrough. Cost savings of up to £0.007 kWh- 1 may be realised compared to existing grab sampling. Using on-line analysis, the performance of full-scale and bench-scale carbon vessels were measured. Full-scale carbon contactors are typically operated at Reynold’s numbers close to the boundary between the laminar and transitional regimes (Re = 40 - 55). This thesis demonstrates, at full- and bench-scale, that increasing the Reynold’s number to site the adsorption process in the transitional regime increases media capacity, by 36% in dry gas and by 400% at 80% humidity. It is postulated that the change in gas velocity profile which occurs as Reynold’s number increases reduces the resistance to siloxane transport caused by gas and water films around the carbon particles, and therefore increases the rate of the overall adsorption process. In the laminar regime (Re = 31) increasing humidity from zero to 80% led to the classical stepwise reduction in adsorption capacity observed by other researchers, caused by the increasing thickness of the water film, but in the transitional regime (Re = 73) increasing humidity had no effect as no significant water film develops. It is therefore recommended that siloxane adsorption vessels should be designed to operate at Reynold’s numbers above 55. By choosing a high aspect ratio (tall and thin) both Reynold’s number and contact time can be optimised.

O amido é o mais abundante dos polissacarídeos de armazenamento de energia de plantas, usualmente depositado na forma de grânulos no citoplasma das células. Também é a principal fonte de energia para o homem, compondo 80-90% dos polissacarídeos da dieta humana, e é o principal responsável pelas propriedades tecnológicas que caracterizam grande parte dos produtos processados. O presente trabalho teve como objetivo a aplicação da ressonância paramagnética eletrônica (RPE) e espectroscopia de Infravermelho por transformada de Fourier (FTIR) ao estudo de amidos irradiados. Amostras em pó de dois amidos naturais, batata (bulbo) e milho (cereal) e farinha de mandioca fermentada ou polvilho azedo (raiz) foram submetidos à ação da radiação ionizante de fonte de 60Co Gammacell 220 com doses de 10, 20 e 30 kGy, taxa de dose de 1kGy h-1. Foram registrados e comparados os espectros de RPE dos três tipos de amidos irradiados e não irradiados. Os amidos apresentaram espectros de RPE semelhantes variando apenas na intensidade do sinal de radicais livres que acompanhou o incremento da dose. Foram estabelecidas as curvas de decaimento para cada um dos amidos ensaiados. No caso de amido de batata o decaimento do sinal apresentou excepcionalmente um comportamento linear quando a dose utilizada foi de 20 kGy. Foi obtido de maneira experimental o valor do fator g, que variou de 2,06062 a 1,94661, sendo o valor teórico g = 2,0023. Foram também estabelecidas as modificações radioinduzidas na estrutura molecular das amostras através da análise dos espectros de absorção no infravermelho por FTIR. / Starch is the most abundant plant energy storage polysaccharide, usually deposited in the form of granules in the cytoplasm of cells. It is also the main source of energy for man, making up 80-90% of polysaccharides in the human diet, and is mainly responsible for the technological properties that characterize most processed products. The present work aimed to the application of electronic paramagnetic resonance and Fourier Transform Infrared Spectroscopy to the study of irradiated starches. Powdered samples of two natural starches, potato (bulb) and corn (cereal) and fermented cassava flour or sour cassava (root) were subjected to the action of ionizing radiation from a 60Co Gammacell 220 at doses of 10, 20 and 30 kGy, dose rate of 1kGy h-1. The electronic paramagnetic resonance spectra of the three types of irradiated and non-irradiated starches were recorded and compared. The starches showed similar electronic paramagnetic resonance spectra varying only in the intensity of the free radical signal that accompanied the dose increase. The decay curves were established for each of the tested starches. In the case of potato starch, signal decay showed an exceptionally linear behavior when the dose used was 20 kGy. The value of factor g was obtained experimentally, ranging from 2.06062 to 1.94661, with the theoretical value g = 2.0023. The radioinduced modifications in the molecular structure of the samples were also established by the analysis of the infrared absorption spectra by Fourier Transform Infrared Spectroscopy.

O amido é o mais abundante dos polissacarídeos de armazenamento de energia de plantas, usualmente depositado na forma de grânulos no citoplasma das células. Também é a principal fonte de energia para o homem, compondo 80-90% dos polissacarídeos da dieta humana, e é o principal responsável pelas propriedades tecnológicas que caracterizam grande parte dos produtos processados. O presente trabalho teve como objetivo a aplicação da ressonância paramagnética eletrônica (RPE) e espectroscopia de Infravermelho por transformada de Fourier (FTIR) ao estudo de amidos irradiados. Amostras em pó de dois amidos naturais, batata (bulbo) e milho (cereal) e farinha de mandioca fermentada ou polvilho azedo (raiz) foram submetidos à ação da radiação ionizante de fonte de 60Co Gammacell 220 com doses de 10, 20 e 30 kGy, taxa de dose de 1kGy h-1. Foram registrados e comparados os espectros de RPE dos três tipos de amidos irradiados e não irradiados. Os amidos apresentaram espectros de RPE semelhantes variando apenas na intensidade do sinal de radicais livres que acompanhou o incremento da dose. Foram estabelecidas as curvas de decaimento para cada um dos amidos ensaiados. No caso de amido de batata o decaimento do sinal apresentou excepcionalmente um comportamento linear quando a dose utilizada foi de 20 kGy. Foi obtido de maneira experimental o valor do fator g, que variou de 2,06062 a 1,94661, sendo o valor teórico g = 2,0023. Foram também estabelecidas as modificações radioinduzidas na estrutura molecular das amostras através da análise dos espectros de absorção no infravermelho por FTIR. / Starch is the most abundant plant energy storage polysaccharide, usually deposited in the form of granules in the cytoplasm of cells. It is also the main source of energy for man, making up 80-90% of polysaccharides in the human diet, and is mainly responsible for the technological properties that characterize most processed products. The present work aimed to the application of electronic paramagnetic resonance and Fourier Transform Infrared Spectroscopy to the study of irradiated starches. Powdered samples of two natural starches, potato (bulb) and corn (cereal) and fermented cassava flour or sour cassava (root) were subjected to the action of ionizing radiation from a 60Co Gammacell 220 at doses of 10, 20 and 30 kGy, dose rate of 1kGy h-1. The electronic paramagnetic resonance spectra of the three types of irradiated and non-irradiated starches were recorded and compared. The starches showed similar electronic paramagnetic resonance spectra varying only in the intensity of the free radical signal that accompanied the dose increase. The decay curves were established for each of the tested starches. In the case of potato starch, signal decay showed an exceptionally linear behavior when the dose used was 20 kGy. The value of factor g was obtained experimentally, ranging from 2.06062 to 1.94661, with the theoretical value g = 2.0023. The radioinduced modifications in the molecular structure of the samples were also established by the analysis of the infrared absorption spectra by Fourier Transform Infrared Spectroscopy.

In this research work different textile materials were buried in soil and their biodegrading pattern will be studied after different specific period of times. / Program: Master Programme in Textile Technology