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Novel Studies on the Formation and Chemical Reactivity of Compound Clusters and Their Precursors in the Gas and Liquid Phase James A. Bradshaw 139 Pages Directed by Dr. Robert L. Whetten Presented are four separate and unique studies on molecular and nanoscale systems: Atmospheric hydration and aggregation of NaCl clusters, highly water-soluble aurous-thiolate oligomers, water-soluble gold clusters from aurous-thiolate oligomer precursors, and gold iodide clusters. Adsorption of water on cationic and anionic sodium chloride clusters is investigated to elucidate active sites of molecular interaction as well as primary aggregate formation kinetics. Considered an exceptionally abundant atmospheric species, experiments are conducted to further quantify gas phase chemistry and hydration/solvation of alkali halides. Currently the most soluble of all known gold-thiolates, para-mercaptobenzoic acid-based (pMBA) aurous-thiolate oligomers are investigated and physical and chemical properties quantified. Solubility, structural conformation, and poly-dispersity of higher homologs are observed with the goal of further applications in clusters research, medical and biomedical, and industry. Gold thiolate clusters, synthesized using pMBA-based oligomers, are investigated through reductive formation in solution. UV-VIS and UV-VIS-NIR spectroscopy is undertaken to assign structures based on predictions of the HOMO-LUMO gap and other electronic transitions. Gold iodide is investigated in relation to the common thiolate-halide analogy. Synthesis and characterization of a solid precursor as well as anion and cation cluster formation is presented as part of an ongoing collaboration.

Diffusion of linear and cyclic poly(oxyethylene) (POE) oligomers in poly(methyl methacrylate) (PMMA) matrix was investigated in situ using attenuated total reflectance (ATR) infrared (IR) spectroscopy technique. The temperatures of studies were 60 oC, 85 oC and 110 oC. A film of PMMA was solution-cast onto an ATR zinc selenide crystal and POE was added to the surface. The IR peak at 1109 cm-1 characteristic to ether bond present in POE was used for quantitative analysis. Deconvolution of this peak from IR spectra allowed us to determine the absorbance of diffusing component as a function of interdiffusion time. The data were fit using appropriate mathematical models from where the interdiffusion constants were extracted and used in diffusion interpretation. By looking at different molecular weight of cyclic and linear POE oligomers diffusing into high molecular weight PMMA matrix, it was possible to analyze how penetrant topology and its molecular weight are influencing the diffusion process. The results indicated that cyclic POE moves faster than linear analogous one and an increase in penetrant molecular weight slows down the interdiffusion. The knowledge gained from this study gives us a deeper understanding of transport behavior of low-molecular-weight additives, such as oligomers into polymer matrices and, in particular the influence of topology on diffusion.

Diss. (sammanfattning) Stockholm : Karol. inst., 2004. / Härtill 5 uppsatser.

Diss. (sammanfattning) Stockholm : Karol. inst., 2005. / Härtill 5 uppsatser.

Thesis (Ph.D.) -- University of Western Sydney, Nepean, 1999. / Bibliography : p. 144-150.

Thesis (Ph.D.)--University of Wollongong, 2005. / Typescript. Includes bibliographical references.

Diss. (sammanfattning)--Stockholm : Karol. inst., 2006. / Härtill 4 uppsatser.

Diss. (sammanfattning) Stockholm : Karolinska institutet, 2006. / Härtill 6 uppsatser.

Thesis (Ph.D.)--Ohio University, June, 2007. / Includes bibliographical references (leaves 186-191)