Thesis (Ph. D.)--University of Hong Kong, 2006. / Title proper from title frame. Also available in printed format.

A novel dual-plasma process for the synthesis of organic layer-coated metal nanoparticles is presented. Metal nanoparticles are synthesized by the low-pressure pulsed arc evaporation of a metal cathode surface, followed by the in-flight deposition of a thin organic layer by capacitively-coupled radio-frequency (CCRF) plasma polymerization from a gaseous hydrocarbon monomer. The system is simple to operate and can be designed for high throughput. The combination of the synthesis and surface treatment of metal nanoparticles in the whole system avoids newly produced metal nanoparticles from being contaminated by surrounding environment. / A home-made self-oscillatory pulsed power supply has been designed and built for the arc evaporation of metal sources. The stability of the pulsed arc system and the cathode erosion rate are discussed. The inductor present in the discharge loop is shown to have a stabilizing effect on the train of pulsed arcs. It was shown that the erosion rate was strongly dependent on peak arc currents due to the increased emission of macroparticles with peak arc currents, and the yield of metal nanoparticles was found to be slightly influenced by the peak arc current. / The produced coated copper nanoparticles were characterized by field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), Fourier-transform infrared spectroscopy (FT-IR), and X-ray photoelectron spectroscopy (XPS). It was revealed that the coated copper nanoparticles have a metal core of size ranging from a few to 50 nm, and that the thickness of the organic layer ranges from 3 to 10 nm. The smallest copper nanoparticles are crystalline, while the organic coating has a macromolecular structure and shows a hydrophobic behavior. The XPS results showed that the plasma polymer film is chemically adsorbed onto the surface of the copper nanoparticle. / The effects of operating conditions such as reactor pressure and inert gas flow rate on the average size of the produced bare copper nanoparticles were studied. It was demonstrated that the metal nanoparticle size tends to decrease with decreasing reactor pressure, while inert gas flow rate has little influence on the mean nanoparticle size. / The morphology of the plasma polymer coating was revealed to be strongly dependent on the RF plasma power, reactor pressure, and inert gas flow rate. Two kinds of organic films were produced: a smooth, uniform and dense polymer film and a liquid polymer film. Based on a series of experiments, a "characteristic map" for the in-flight plasma polymerization from the C2H 6 monomer generating an organic layer onto the Cu nanoparticles was developed. A simplified free-radical mechanism was proposed for the plasma polymerization from ethane. / Other metal sources such as iron and aluminum were used as cathodes in the arc evaporation reactor. Transmission electron microscopy confirmed the production of coated nanoparticles similar in morphology to the ones obtained with the copper cathode. Lastly, ethylene glycol vapor were introduced as an alternative monomer into the plasma polymerization region. A non-uniform coating was observed on the metal nanoparticle surface.

This thesis is concerned with the development of ab-initio molecular dynamics (AIMD) using density functional theory, and its application to simple diatomics and small sodium clusters. The approach follows Car and Parrinello and the local spin density (LSD) approximation is taken as a starting point for the description of the electronic states in these systems. An improvement to LSD by correcting for the spurious self-interaction terms (SIC), as proposed by Perdew and Zunger, and the way in which this can be implemented is considered. The SIC corrected LSD is tested on simple diatomic molecules, and is shown, especially for the case of H₂, to significantly improve on the LSD description of the potential energy curve and the spin pairing/unpairing transition. LSD and SIC are then compared for small sodium clusters, for which the geometries, binding energies, and polarizabilities are determined, as well as vibrational frequencies for two clusters. Conclusions are hampered by the lack of experimental data, and uncertainties due to the pseudopotential. However SIC gives a more accurate description of the binding energies, and the unique SIC orbitals allow a description of the bonding which accurately predicts the relative stabilities of the clusters and rationalises their geometries. The problems of breakdown of the Car-Parrinello (CP) method due to "nonadiabatic" effects is considered and it is shown that the problems arising during bond formation and bond breaking, as illustrated by the case of Na₂, can largely be overcome by applying an external thermostat to the fake degrees of freedom. This method is then tested using the dynamics of small sodium clusters. In particular the dynamics of the pseudorotation of Na₃ is studied and it is shown that the mechanism and information about the kinetics can be determined. Finally other methods for improving upon LSD are considered. It is shown that gradient corrections using a plane wave basis set have inherent problems in implementation. Implementation of the exact Hartree-Fock exchange is considered, and this in conjunction with a form of self-interaction correction on the correlation is shown give very accurate results for simple diatomics which are cheaper than using full configuration interaction methods.

Thesis (M.Eng.). / Written for the Dept. of Chemical Engineering. Title from title page of PDF (viewed 2008/03/12). Includes bibliographical references.

Thesis (M.Eng.). / Written for the Dept. of Chemical Engineering. Title from title page of PDF (viewed 2008/04/12). Includes bibliographical references.

Thesis (Ph.D.)--York University, 2009. Graduate Programme in Physics & Astronomy. / Typescript. Includes bibliographical references (leaves 179-198). Also available on the Internet. MODE OF ACCESS via web browser by entering the following URL: http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&res_dat=xri:pqdiss&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&rft_dat=xri:pqdiss:NR51495

Thesis (Ph. D.)--Chemistry and Biochemistry, Georgia Institute of Technology, 2007. / Whetten, Robert, Committee Member ; Wang, Z.L., Committee Member ; Perry, Joe, Committee Member ; El-Sayed, Mostafa A., Committee Chair ; Orlando, Thomas, Committee Member.

No description available.

Thesis (Ph. D.)--University of Nevada, Reno, 2005. / "August, 2005." Includes bibliographical references. Online version available on the World Wide Web. Library also has microfilm. Ann Arbor, Mich. : ProQuest Information and Learning Company, [2005]. 1 microfilm reel ; 35 mm.

published_or_final_version / abstract / toc / Chemistry / Master / Master of Philosophy