Thesis (PH. D.)--University of Nebraska, 1934. / Bibliography: p. 34-35. Also issued in print.

Thesis (Ph. D.)--Oregon State University, 2009. / Printout. Includes bibliographical references. Also available on the World Wide Web.

Thesis (PH. D.)--University of Nebraska, 1934. / eContent provider-neutral record in process. Description based on print version record. Bibliography: p. 34-35.

Thesis (Ph. D.)--University of Hong Kong, 1999. / Includes bibliographical references (leaves 138-152).

Thesis (Ph. D.)--University of Wisconsin--Madison, 1958. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.: leaves 82-84.

Thesis (M.Sc.) -- Memorial University of Newfoundland. / Typescript. Bibliography : leaves 73-76. Also available online.

Thesis (M.S.)--University of Texas at El Paso, 2007. / Title from title screen. Vita. CD-ROM. Includes bibliographical references. Also available online.

Dans ce travail avons mis en évidence l’influence de la puissance radio-fréquence (RF) sur les différentes propriétés microstructurales, optiques, électriques, paramagnétiques ainsi que la morphologie des films minces polymérisés par PECVD capacitive, en utilisant la vapeur du cyclohexane comme précurseur.A faible puissance RF les surfaces de nos films sont poreuses et fortement hydrogénées. Elles possèdent un caractère hydrophile. L’augmentation de la puissance RF (à partir de 120 W) engendre une microstructure moins hydrogénée des couches et favorise les réarrangements atomiques entre les atomes de carbone et notamment, la formation de liaisons de type C=C (C-sp²). Dans cette gamme de puissance nous avons réussi à augmenter le caractère conducteur de nos films polymérisés. Ces résultats sont en bon accord avec les mesures optiques qui montrent qu'à forte puissance RF les films obtenus sont plus durs (augmentation de n avec la puissance) et leur gap optique est de plus en plus faible. Cette diminution du gap optique a été interprétée en termes de distorsions, de graphitisation et de réorganisation des sites C-sp2 pour former des amas plus grands et mieux organisés. Il apparaît, en combinant ces mesures avec celles obtenues sur la microstructure (Raman et Infrarouge), que l’augmentation de la conductivité électrique et la diminution du gap optique correspondent à une augmentation du nombre des doubles liaisons C=C, c’est-à-dire, une « graphitisation » du film favorisant ainsi le caractère conducteur.Néanmoins, la conductivité électrique reste faible, ce qui est expliqué par les mesures de résonance paramagnétique électronique (RPE), qui montrent qu’il existe des défauts au sein des sites C-sp2 et que la densité de spins augmente avec la puissance RF, indiquant que la densité de défauts augmente dans les films minces déposés à forte puissance RF. De plus le rétrécissement des raies RPE lorsque la puissance RF augmente, indique la diminution de l’interaction d’échange entre les spins suite à leur délocalisation dans les structures des liaisons . / In this work we have shown the influence of the radio frequency (RF) power on the microstructural, optical, electrical, electronic and morphological properties of thin films polymerized by capacitive PECVD using cyclohexane as precursor gas.At low RF power, the surfaces of our films are porous and highly hydrogenated. They have a hydrophilic character. The increase in the RF power (above 120 W) generates less hydrogenated microstructure and promotes atomic rearrangements between the carbon atoms, including the formation of C = C (C-sp²) bonds. In this RF power range we observed an increase of the conductor character of our polymerized films. These results are in good agreement with optical measurements, show that high RF power induces harder deposited films (increase of n with RF power) and a decrease in the optical gap. This decrease in the optical gap was interpreted in terms of distortions, graphitization and reorganization of the C-sp2 sites, which form larger and better organized clusters. It appears, by combining these measurements with those obtained on the microstructure (Raman and FTIR), that the increase in the electrical conductivity and the decrease of the optical gap is associated with the increase in the number of C = C double bonds, that is to say a "graphitization" of the film, promoting the conductive nature.However, the electrical conductivity values are still a little low, which is explained by the electron paramagnetic resonance (EPR) measurements, which showed the presence of defects within the C-sp2 sites, and that the spin density increases with RF power, suggesting an increase in the defect density in the thin films deposited at high RF power. Furthermore, the narrowing of the EPR lines when the RF power increases indicates a decrease in the exchange interaction between spins as a result of delocalization phenomena in the  bond structures.

M.Sc. / The main objective of this study was to identify and optimise the homogeneous catalytic systems for Pd(II) catalysed alkene acetoxylation in acetic acid to directly yield allyl or vinyl acetates as opposed to the usual aldehydes or ketones. Part of the intention of this study was to investigate potentially suitable re-oxidants and reaction conditions suitable for industrial application. The synthesis of butenyl acetate (via 1-butene acetoxylation) in particular is regarded as a potential value-adding opportunity for solvents producers. For safety considerations the study was performed with liquid alkenes (cyclohexene, cyclopentene, cycloheptene, cyclooctene and 1-hexene). Cyclohexene was used for the bulk of these studies. One of the most important and pioneering reactions in this field is the similar system for the oxidation of alkenes to ketones (the Wacker process). The related reaction, oxidative acetoxylation, is the result of the discovery of the Wacker process. The problems associated with both these reactions is the difficulty in re-oxidising the catalyst Pd once it has been reduced in the catalytic process from Pd(II) to Pd(0). Various reaction systems have been developed to improve these processes. Some of the systems that have been developed in the acetoxylation of alkenes were investigated. From the studies it has become obvious that for ease of Pd(0) re-oxidation a co-catalyst, benzoquinone, is essential for the catalytic process. This system employing a co-catalyst required another oxygen efficient re-oxidant to oxidize hydroquinone once reduced from benzoquinone in the oxidation of Pd(0). The re-oxidant would in turn be oxidized by oxygen. Various types of re-oxidants such as Cu(II) salts, heteropolyacids and metal macrocycles (e.g. Schiff base complexes and phthalocyanine metal complexes) were investigated in the multi-step electron transfer process. The most promising of the systems was the Pd(OAc)2/ benzoquinone/ heteropolyacid (H5PMo10V2O40 .34H2O)/ O2 system. From the studies it was apparent that the type of the re-oxidant can influence the yield of the product. Various other parameters were found to influence the reaction outcome. The type of Pd(II) salt was found to be influential in the reaction, for instance Pd(OAc)2 was found to be a better catalyst than Pd(CF3CO2)2. The catalyst loading was found to improve the yield iv when increased whilst this was not trivial since Pd is expensive the system needed to have as low catalyst loading as possible. The type of alkene used dictated the rate of the reaction and the product distribution. It was found that the conditions used for cyclohexene were not transferable to other alkenes without changing certain parameters to suit the alkene in question. Cycloalkenes acetoxylation was found to proceed without the addition of the strong nucleophile additive NaOAc, whilst for 1-hexene acetoxylation the reaction did not proceed without the additive. The product distribution was found to also differ between cycloalkenes and 1-hexene. For cyclohexene the by-products observed were the disproportionation products cyclohexane and benzene. In the case of 1-hexene the by-products were 2-hexanone (the Wacker reaction) and 2-hexenes (isomerisation). The operating temperature also played a role in the reaction outcome. In some instances the increase in reaction temperature negatively affected the reaction whilst in other cases it improved the reaction. Oxygen pressure also influenced the reaction to a lesser extent, with an increase in pressure favouring the reaction.

No description available.