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Articles 1 - 7 of 7
Full-Text Articles in Physical Sciences and Mathematics
Manganese Oxide Mineral Phases Produced At Room Temperature Under Acidic Conditions Investigated With Xrd, Tem, Sem, Eds, And Bet, Nancy R. Birkner
Manganese Oxide Mineral Phases Produced At Room Temperature Under Acidic Conditions Investigated With Xrd, Tem, Sem, Eds, And Bet, Nancy R. Birkner
UNLV Theses, Dissertations, Professional Papers, and Capstones
This thesis concerns characterization of synthetic manganese oxides belonging to mineral phases known as Birnessite and Cryptomelane. Presented here are the results of an experiment designed to examine the influence of sodium, potassium, chloride, and sulfate ions on the reduction of potassium permanganate under acidic conditions at room temperature to produce Birnessite and Cryptomelane. The experiments used KMnO4 as the source of Mn and the resulting Birnessite and Cryptomelane precipitates were washed with 18 Mn/cm NANOpure water at the end of syntheses. Several state-of-the-art solid state techniques were used to characterize the Mn-based oxide mineral phases. Based on the literature …
Plasmonic Enhancement Of Forster Energy Transfer Between Two Molecules In The Vicinity Of A Metallic Nanoparticle: Nonlocal Optical Effects, P.T. Leung, H. Y. Xie, H. Y. Chung, D. P. Tsai
Plasmonic Enhancement Of Forster Energy Transfer Between Two Molecules In The Vicinity Of A Metallic Nanoparticle: Nonlocal Optical Effects, P.T. Leung, H. Y. Xie, H. Y. Chung, D. P. Tsai
Physics Faculty Publications and Presentations
The problem of Forster resonance energy transfer (FRET) between two molecules in the vicinity of a metallic nanoparticle such as a nanoshell is studied within a phenomenological model which takes into account the nonlocal optical response of the metal. This model allows for arbitrary locations and orientations of the two molecular dipoles with respect to the metal particle which can be of ultrasmall sizes (nm) and for which nonlocal effects are of high significance. In particular, for the nanoshell case, the molecules can be located both outside, both inside, or one inside and one outside the shell. Also, the case …
Nanostructured Semiconductor Heterojunctions From Quantum Dot Layers, Rolf Könenkamp, Robert Campbell Word, Athavan Nadarajah
Nanostructured Semiconductor Heterojunctions From Quantum Dot Layers, Rolf Könenkamp, Robert Campbell Word, Athavan Nadarajah
Physics Faculty Publications and Presentations
We report the deposition of conformal thin layers of 10?50 nm thickness from II-VI quantum dot suspensions on ZnO nanowire substrates. Smooth polycrystalline films of high electronic quality can be obtained from CdSe quantum dots after annealing at moderate temperatures. The electronic properties are adequate for detector and solar cell applications. The growth and annealing temperatures permit deposition on light-weight and flexible substrates. Some elemental diffusion of Se across the CdSe/ZnO interface occurs in the film formation. A comparison with CdS/ZnO junctions indicates that the low Se diffusion rates are essential for efficient charge transfer.
Optical Properties Of Multilayer-Polyelectrolyte Films With Incorporated Gold Nanomaterials (Solid Nanoparticles And Hollow Nanoshells), Robert Watson Day
Optical Properties Of Multilayer-Polyelectrolyte Films With Incorporated Gold Nanomaterials (Solid Nanoparticles And Hollow Nanoshells), Robert Watson Day
Honors Theses
The growth of various multilayer‐polymer multilayer‐nanoparticle films was successfully achieved. Multilayer‐polymer multilayer‐nanoparticle films with 1, 3, and 5 polymer layers between nanoparticle layers exhibit significantly different optical properties due to the differences in magnitude of particle plasmon coupling. These film systems were also successfully extended to hollow gold nanoshells, which have significantly enhanced optical properties in comparison to solid gold nanoparticles of similar sizes. A proposal for utilizing this increased sensitivity of the gold nanoshells to explore the ‘microenvironments’ for optimizing potential sensing applications is also presented.
A Photochemically Initiated Chemistry For Coupling Underivatized Carbohydrates To Gold Nanoparticles, Xin Wang, Olof Ramström, Mingdi Yan
A Photochemically Initiated Chemistry For Coupling Underivatized Carbohydrates To Gold Nanoparticles, Xin Wang, Olof Ramström, Mingdi Yan
Chemistry Faculty Publications and Presentations
The sensitive optoelectronic properties of metal nanoparticles make nanoparticle-based materials a powerful tool to study fundamental biorecognition processes. Here we present a new and versatile method for coupling underivatized carbohydrates to gold nanoparticles (Au NPs) via the photochemically induced reaction of perfluorophenylazide (PFPA). A one-pot procedure was developed where Au NPs were synthesized and functionalized with PFPA by a ligand-exchange reaction. Carbohydrates were subsequently immobilized on the NPs by a fast light activation. The coupling reaction was efficient, resulting in high coupling yield as well as high ligand surface coverage. A colorimetric system based on the carbohydrate-modified Au NPs was …
Nanocomposite Thin Films Of Au Nanoparticles Embedded In Yttria-Stabilized Zirconia For Plasmonic-Based Harsh Environment Gas Detection, Phillip Henry Rogers
Nanocomposite Thin Films Of Au Nanoparticles Embedded In Yttria-Stabilized Zirconia For Plasmonic-Based Harsh Environment Gas Detection, Phillip Henry Rogers
Legacy Theses & Dissertations (2009 - 2024)
Increased health concerns due to the emission of gases linked to the production of tropospheric ozone by petroleum based fuel burning engines has resulted in the codification of more stringent emissions regulations domestically. Emissions regulations on commercial jetliners are one of the areas to be met with stricter standards. Currently there is not a sensing technology that can detect the emissions gases in the exhaust stream of a jet turbine engine with lower detection limits that meet these standards.
Polyelectrolyte-Linked, Multi-Layer Film Assemblies Of Aqueous Nanoparticles And Nanoshells, Anne Galyean
Polyelectrolyte-Linked, Multi-Layer Film Assemblies Of Aqueous Nanoparticles And Nanoshells, Anne Galyean
Honors Theses
Multi-layer films of nanoparticles and nanoshells featuring various polymeric linkage molecules have been assembled and their optical properties characterized. The growth dynamics, including molecular weight effects, and stability of the various nanoparticle film constructions, using both single polymer as well as combinations of alternating charge polyelectrolytes as linking mechanisms, are presented. The polymeric linkers studied include poly-L-lysine, poly-L-arginine, poly(allylamine hydrochloride), and polyamidoamine dendrimers. Significantly air stable films were achieved with the use of multi-layered polymeric bridges between the nanoparticles and nanoshells. Optical sensitivity normally observed with these nanomaterials in solution was observed for their corresponding film geometries, with the nanoshell …