Thesis (Ph. D.)--University of Oregon, 2001. / Typescript. Includes vita and abstract. Includes bibliographical references (leaves 198-209). Also available for download via the World Wide Web; free to University of Oregon users.

No description available.

Thesis (MScIng)--University of Stellenbosch, 2008. / Bibliography. Also available via the Internet.

Thesis (M.S.)--Marshall University, 2004. / Title from document title page. Abstract included. Document formatted into pages; contains viii, 96 p. including illustrations. Includes abstract. Includes bibliographical references (p. 95-96).

Thesis (Ph.D.)--University of Delaware, 2009. / Principal faculty advisor: Brian G. Willis, Dept. of Chemical Engineering. Includes bibliographical references.

Thesis (M.S.)--University of Florida, 2004. / Title from title page of source document. Document formatted into pages; contains 158 pages. Includes vita. Includes bibliographical references.

Thesis (M.S.)--Miami University, Dept. of Physics, 2005. / Title from first page of PDF document. Document formatted into pages; contains [1], xvi, 202 p. : ill. Includes bibliographical references (p. 183-184).

The full potential of Langmuir Blodgett (LB) Technology will only be realised in the development of sensors, such as coated metal electrodes, if the problems related to film stability in an aqueous environment can be overcome. To this end, the ac admittance technique has been applied to characterise LB films of Barium Stearate and Poly-ButylMethacrylate, deposited onto platinum, copper and aluminium electrodes immersed in a range of electrolytes. Cyclic voltammetry was used as a complementary characterisation technique for the coatings on platinum. Equations were derived to relate the measured cell admittance to the equivalent circuit parameters. Approximations to these equations, valid for limited frequency ranges, enable parameter estimates to be made from the double log plots of capacitance and loss against frequency. The admittance data was analysed in terms of an equivalent circuit model adapted from the work of Macdonald (1952,1971,1973,1974,1976,1985). This treatment enables the electrical measurements to be related to the electrical double layer, electrolyte and deposited film and represents the first attempt to characterise LB films in this way. The equivalent circuit model was rigorously applied to the characterisation of i) PCB electrodes spin coated with PVC and ii) sputtered copper electrodes coated with Barium Stearate using the LB Technique. Several processes are found to contribute to the molarity, electrolyte and time dependent changes in coating admittance. For example, ionic uptake leads to an increase in coating admittance which can introduce a marked frequency dependent dispersion. For less stable coatings, film reorientation and desorption and changes in the oxide of the metal electrode can also affect the measured admittance. LB films of PBMA deposited onto platinum were sufficiently stable for immobilising electroactive species. Valinomycin incorporated in an LB film of PBMA and deposited onto platinum exhibited a reversible tt [K+] dependent conductance.

This dissertation presents detailed studies of the electronic structures of two molecular systems, iron monocarbide (FeC) and rhenium mononitride (ReN). There had been no research on either molecule prior to the present investigation. FeC is the first 3d transition metal carbide to have been characterized spectroscopically. The ground electronic state of FeC has been established in our studies to be an inverted ³Δ (³δσ¹) state, based on the experimental observations and molecular orbital considerations. Laser-induced-fiuorescence signals originating from the two lowest spin components of the ground X³Δ₁ state were observed. Investigation of the excitation spectrum of the molecule revealed two ³Δ₃ states and two ³Δ₂ states. A strongly perturbed band at 448nm was also rotationally analyzed and deperturbed. It involves three vibronic states with Ω=3.... / Graduate

The electrical properties of metal-molecular nanoparticle networks are studied both theoretically and experimentally. Benzenedithiol-aluminum cluster linear chains, Y-shaped and H-shaped networks are modeled with semi-empirical methods to study the electronic properties of such structures. The HOMO (highest occupied molecular orbital)-LUMO (lowest unoccupied molecular orbital) gaps of the benzenedithiol-Al cluster networks decrease several eV compared to the isolated benzenedithiol molecule. Frontier energy levels become more closely spaced as the size of the molecular networks increase, accompanied with an increased HOMO energy and decreased LUMO energy, indicating a decreased energy barrier to electron transport. Delocalized spatial distribution of the frontier orbitals indicates a high probability for electron transmission and corresponds well with peaks near the HOMO-LUMO gap in the electronic density of states. Self-assembled molecular networks consisting of dithiol/thiol molecules and 30 nm colloidal gold nanoparticles are fabricated with a solution-based method. Electrical measurements performed on these nanostructures show a typically linear current-voltage characteristic while nonlinear I-V curves are also observed for networks built of benzenedithiol or hexane/octanethiol molecules. Further analysis with atomic force microscopy shows that the network’s conductance is determined by the molecule’s conductivity and network dimensions. Circuit model consisting of networked molecular resistors is applied to study the interconnections between the particles within the network and the simulated values of the network’s conductance is consistent with the measured values. Theoretical and experimental study on the electrical properties of metal-molecular nanoparticle networks reveals the influence of molecules and metallic particles on determining the network’s conductivity. Such self-assembled networks can be used to implement several circuit elements, such as resistors, diodes, etc., and more complicated computation components such as nanocells, memristors, etc. The electrical properties of the networks can be tuned by proper choice of molecules, metallic particles and network geometry making them promising for future molecular electronic circuits. / Graduate