The goal of this project was to study the behavior of copper oxide nanoparticles in soil environments. Copper oxide nanoparticles have antimicrobial properties and may also be used in agricultural settings to provide a source of copper for plant health, but accidental or misapplication of these nanoparticles to soil may be damaging to the plant and its associated bacteria. Dissolved soil organic matter that is present in soil pore waters dissolved nanoparticles, but did not dissolve the expected amounts from a geochemical model because the geochemical model did not take into account surface chemistry or coating of the nanoparticles by dissolved organic matter. Wheat grown in soil pore water increased the solubility of the nanoparticles. The nanoparticles and dissolved copper were harmful to wheat, but dissolved soil organic matter remediated a portion of the damage. These studies were conducted with Utah soils and wheat, a highly valuable Utah crop. These results suggest that contamination of soils by copper oxide nanoparticles will be partially mitigated by the organic matter content of the soil. Producers of fertilizers and fungicides may use various forms of organic matter to deliver products that are targeted to specific plants or pathogens and avoid damage to non-target organisms.

Microalgae are increasingly involved in the diet due to their beneficial effects on human health and therefore they are more often studied. Nowadays, there is a trend of using nanotechnology. The undesirable effects of copper oxide nanoparticles (CuO) attract more and more attention today. Since, there is an increasing demand for fossil fuels and simultaneously the amount of CO2 is increasing in the air, microalgae could serve in future as renewable fuels thanks to its rapid grow properties. In the diploma thesis, I dealt with the amount of carotenoid and polyphenolic substances in the algae Chlorella vulgaris after the influence of CuO nanoparticles. Experimental part of this work summarizes the results, revealing that CuO nanoparticles caused decrease of chlorophyle a by up to 60 % with CuO nanoparticles concetration of 25 mg/l, together with significant decrease of chlorophyle b and carotenoids. The amount of polyphenols and flavonoids in biomass has been changed only minimaly. In contrast, with usage of increasing concentration of CuO nanoparticles I found out by the SPOT test the increase of biomass in algae. Significant changes in selected secondary metabolites has been observed. The greatest statistically significant (p<0,01) growth with concetration 5 mg/l (1,08 ± 0,05 µg/g dry weight) has been observed for pOHbenzaldehyde, with increase by 42 % compared to control. In contrast rapid decrease has been noted with concentration 25 mg/l (0,06 ± 0,04 µg/g dry weight)

L’objectif de ce travail est l’étude et la modélisation d’un capteur de gaz à base d’oxyde métallique semiconducteur de type p (cas de CuO). Pour cela, des couches minces de CuO ont été élaborées dans l‘équipe microcapteurs de IM2NP à partir de deux techniques différentes : la pulvérisation cathodique réactive magnétron radio-fréquence et l’oxydation thermique des couches minces de cuivre déposées par évaporation thermique sous vide. Différentes techniques de caractérisation ont été mises en oeuvre pour évaluer les propriétés des couches minces obtenues en vue de les optimiser pour l’application capteur. La microscopie à force atomique (AFM) et la microscopie électronique à balayage (MEB) ont révélé une nanostructure homogène dont la morphologie présente la porosité désirée. Les analyses par diffraction de rayons X (DRX) ont montré que ces couches minces présentent une monophase de CuO avec une orientation préférentielle (111), les études optiques par ellipsométrie dans le domaine visible ont permis d’estimer les pourcentages de porosité dans chaque couche. Ces couches possèdent la cristallinité et la pureté requises pour l'utilisation en capteurs de gaz. Les performances de ces couches minces de CuO ont été évaluées pour la détection de l’ozone et de l’éthanol. Sur la base de ces résultats, un modèle dynamique a été développé simulant la réaction entre les espèces oxygénées ionisées adsorbées à la surface d'un semiconducteur de type p avec un gaz, qui permet d’évaluer l’influence des paramètres de fonctionnement (Température de fonctionnement, pression d’oxygène et concentration de gaz). / The objective of this work is to study and model a gas sensor based on a p-type metal oxide semiconductor (case of CuO). For this, thin layers of CuO have been developed in the microsensor team at the IM2NP laboratory from two different techniques: radio frequency reactive magnetron sputtering and thermal oxidation of thin copper films deposited by thermal evaporation under vacuum. Different characterization techniques have been implemented to evaluate the properties of the thin films obtained in order to optimize them for sensor applications. Atomic force microscopy (AFM) and scanning electron microscopy (SEM) revealed a homogeneous nanostructured morphology which has the desired porosity. Diffraction analysis (XRD) showed that these thin films have a single phase of CuO with a preferred orientation (111). Optical studies by ellipsometry in the visible spectral region were used to estimate the percentage of porosity in each layer. These layers have the crystallinity and purity required for use in gas sensors. The performances of these thin layers of CuO were evaluated for the detection of ozone and ethanol. Based on these results, a dynamic model was developed to simulate the reaction between the ionized oxygen species adsorbed on the surface of a p-type semiconductor with a gas, which is used to evaluate the influence of operating parameters (working temperature, oxygen concentration and gas pressure).

Cette thèse présente les résultats expérimentaux relatifs à l'étude des couches de GaN et de CuO déposées par la technique PLD (dépôt par laser à impulsions) sur des substrats de saphir, SrTiO3, quartz et MgO. Nous avons étudié les effets de plusieurs paramètres qui jouent sur la cristallisation et la morphologie des surfaces des films déposés, à savoir, la température du substrat, la pression au fond, la distance entre le substrat et la cible, la densité d'énergie du laser et la position du substrat. Les couches ont été caractérisées par XRD, microscopie à force atomique et Le microscope électronique à balayage, RHEED et RAMAN. Les résultats montrent que la rugosité et la qualité de la surface des films déposés par PLD dépendent de l'énergie cinétique de déposition des espèces chimiques. L'épaisseur du film, la cristallinité, l'homogénéité et la rugosité sont étroitement liés aux conditions de dépôt / The thesis presents experimental results related to the Pulsed Laser Deposition (PLD) of GaN and CuO thin films using sapphire, SrTiO3, quartz and MgO substrates. The evolution of crystallization and surface morphology of the as-deposited films were studied to investigate the influence of the process conditions such as: substrate heating, background pressure, target-substrate distance, laser energy density, and substrate location, which were systematically varied. The as-deposited films were characterized by X-ray diffraction, atomic force microscopy and scanning electron microscopy, X-ray photoelectron spectroscopy, RHEED and RAMAN techniques. The results convincingly demonstrate that the enhancement in film growth quality - the reduction in roughness and the delay of epitaxial breakdown - is related to the control of PLD species kinetics. The films thickness, crystallinity, homogeneity and surface roughness are strongly dependent on deposition conditions

Nanoparticles (NP) offer great merits over controlling thermal, chemical and physical properties when compared to their micro-sized counterparts. The effectiveness of the dispersion of the NP is the key aspect of the applications in nanotechnology. The project studies the characterization and modification of functional NPs aided by the means of large scale molecular thermal dynamic computerized dispersing simulations, in the level of Nanoclusters (NC). Carrying out NP functionality characterisation in fluids can be enhanced, and analysed through computational simulation based on their interactions with fluidic media; in terms of thermo-mechanical, dynamic, physical, chemical and rheological properties. From the engineering perspective, effective characterizations of the nanofluids have also been carried out based on the particles sizes and particle-fluids Brownian motion (BM) theory. The study covered firstly, investigation of the pure CuO NP diffusion in water and hydrocarbon fluids, secondly, examination of the modified CuO NP diffusion in water. In both cases the studies were put under experiments and simulations for data collection and comparison. For simulation the COMPASS forcefield, smoothed particle hydrodynamic potential (SPH) and discrete particle dynamics potential (DPD) were implemented through the system. Excellent prediction of BM, Van der Waals interaction, electrostatic interaction and a number of force-fields in the system were exploited. The experimental results trend demonstrated high coherence with the simulation results. At first the diffusion coefficient was found to be 1.7e-8m2/s in the study of CuO NC in water based fluidic system. Secondly highly concurrent simulation results (i.e. data for viscosity and thermal conductivity) have been computed to experimental coherence. The viscosity trend of MD simulation and experimental results show a high level of convergence for temperatures between 303-323K. The simulated thermal conductivity of the water-CuO nanofluid was between 0.6—0.75W•m−1•K−1, showing a slight increase following a rise in temperature from 303 to 323 K. Moreover, the alkane-CuO nanofluid experimental and simulated work was also carried out, for analysing the thermo-physical quantities. The alkane-CuO nanofluid viscosity was found 0.9—2.7mpas and thermal conductivity is between 0.1—0.4W•m−1•K−1. Finally, the successful modification of the NPs on experimental and simulation platform has been analysed using different characterization variables. Experimental modification data has been quantified by using Fourier Transformation Infrared (FTIR) peak response, from particular ranges of interest i.e. 1667-1609cm-1 and 1668-1557cm-1. These FTIR peaks deduced Carboxylate attachment on the surface of NPs. Later, MD simulation was approached to mimic experimental setup of modification chemistry and similar agglomerations were observed as during experimental conditions. However, this approach has not been presented before; therefore this study has a significant impact on describing the agglomeration of modified NPs on simulation and experimental basis. Henceforth, the methodology established for metal oxide nanoparticle dispersion simulation is a novelty of this work.

Thesis (M.A.)--Si li Zhongguo wen hua xue yuan, 1965. / On double leaves. Includes bibliographical references (leaves 169-170).

Ce travail de thèse porte sur la compréhension et la modélisation de la combustion de mélange de nanoparticules composée d'aluminium et d'oxydes métallique. Dans ce cadre, nous avons développé un modèle cinétique, reposant sur un ensemble de phénomènes élémentaires : diffusion, réactions, condensations, évaporations et décompositions. Nous avons montré que ce modèle permet de prédire l'évolution de la pression généré en fonction de nombreux paramètres : la compaction, la proportion d'aluminium et d'oxyde métallique et la taille des particules du mélange. Enfin, ce modèle a été couplé à une description des transferts thermiques lors de la combustion, afin d'étudier l'effet des pertes thermiques dans une chambre de combustion. / This thesis work deals with understanding and modeling the combustion of a mixture of nanoparticle made of aluminum and metal oxide. In this context, we developed a kinetic model, based on multiple elementary phenomena : diffusion, reaction, condensation, vaporization and decomposition. We showed that this model allows to predict the evolution of the pressure generated during the combustion as a function of multiple parameters : packing, proportion of aluminum and metal oxide, and particle sizes. Finally, this model have been coupled with a description of the thermal transport, in order to study the effect of heat losses in a combustion chamber.

京都大学 / 0048 / 新制・課程博士 / 博士(エネルギー科学) / 甲第17795号 / エネ博第278号 / 新制||エネ||58(附属図書館) / 30602 / 京都大学大学院エネルギー科学研究科エネルギー社会・環境科学専攻 / (主査)教授 石原 慶一, 教授 東野 達, 准教授 奥村 英之 / 学位規則第4条第1項該当 / Doctor of Energy Science / Kyoto University / DFAM

The aim of the study is to evaluate the ability of non-noble metal catalysts to function as the commercially used noble metal catalyst. The exhaust gas that was used in the project is generated from a heater developed by ReformTech AB with diesel as fuel. The compound that was focused on is carbon monoxide that has a concentration of 300-750 ppm. The catalysts that were tested are MnO/CeO2, CuO/CeO2 and a Pt/CeO2 catalyst used to compare the non-noble metal catalyst with. The sensitivity against sulfur poisoning was also analyzed by mixing sulfur into the fuel. Analysis of the exhaust gas was done with a micro-GC and the catalysts were also analyzed with SEM before and after exposure of sulfur.   The manganese catalyst with a loading of 7 wt-% did not show any activity against carbon monoxide oxidation. The copper catalysts contained two different loadings of active material, 7 and 14 wt-% and monoliths with 400 and 600 cpsi were used. Both loadings showed good activity against carbon monoxide oxidation.   The most prominent catalyst was the 14 wt-% CuO/CeO2 catalyst with a 600 cpsi monolith because of an increase in surface area. The SEM analysis showed that sulfur was present on the surface when the heater was using diesel with 300 ppm sulfur. The sulfur caused complete deactivation of the non-noble metal catalysts and a small decrease in activity was shown on the noble metal Pt catalyst.

La miniaturisation des appareils électroniques et la multiplication de leur fonctionnalités explique l’intérêt croissant porté aux microsources d’énergie telles que les microbatteries au lithium. Ces dernières sont principalement conçues pour une utilisation rechargeable, mais des systèmes non rechargeables peuvent également êtes envisagés pour certaines applications. Actuellement, la principale limitation de ces systèmes est leur capacité surfacique, n’excédant pas 200 µAh.cm-2. Afin d’obtenir une forte capacité surfacique, nous nous sommes intéressés à CuO, un matériau réagissant avec le lithium suivant un mécanisme de conversion, et présentant une capacité volumique théorique élevée (425 µAh .cm-2.µm-1). Des couches minces de CuO ont ainsi été préparées par pulvérisation radiofréquence à cathode magnétron sous atmosphère réactive (Ar + O2). L’influence des paramètres de dépôts (concentration d’oxygène, pression totale, température des substrats, distance cible-substrat, configuration de la cible) sur leurs propriétés chimiques, morphologiques et structurales a été étudiée. Ces dernières ont également été corrélées à leurs performances électrochimiques, obtenues avec un électrolyte liquide ou un électrolyte solide. / The miniaturization of electronic components and their increasing number of functionalities induce a great interest for energy microsources such as thin films batteries. There are mainly developed for secondary systems, even if primary systems are also convenient for some applications. Currently, the main limitation is their specific capacity which does not exceed 200 µAh.cm 2.µm 1. In order to get a system having a high surfacic capacity, we focused on CuO, which react with lithium according to a conversion mechanism and exhibit a large theoretical capacity (425 µAh .cm-2.µm-1). CuO thin films were prepared by radiofrequency magnetron sputtering in a reactive mixture (Ar + O2). The influence of some deposition parameters (oxygen concentration, total pressure, substrate-target distance, the intentional heating or not of the substrates, target configuration) on their chemical, morphological and structural properties were investigated. The latter were also linked to their electrochemical performances, obtained with a liquid electrolyte or a solid electrolyte.