Nanoscience and Nanotechnology Commons^™

Infrared Energy Conversion In Plasmonic Fields At Two-Dimensional Semiconductors, Gregory Thomas Forcherio

Graduate Theses and Dissertations

Conversion of infrared energy within plasmonic fields at two-dimensional, semiconductive transition metal dichalcogenides (TMD) through plasmonic hot electron transport and nonlinear frequency mixing has important implications in next-generation optoelectronics. Drude-Lorentz theory and approximate discrete dipole (DDA) solutions to Maxwell’s equations guided metal nanoantenna design towards strong infrared localized surface plasmon resonance (LSPR). Excitation and damping dynamics of LSPR in heterostructures of noble metal nanoantennas and molybdenum- or tungsten-disulfide (MoS2; WS2) monolayers were examined by parallel synthesis of (i) DDA electrodynamic simulations and (ii) near-field electron energy loss (EELS) and far-field optical transmission UV-vis spectroscopic measurements. Susceptibility to second-order nonlinear frequency …

Characterization Of Coupled Gold Nanoparticles In A Sparsely Populated Square Lattice, Roy Truett French Iii

Graduate Theses and Dissertations

Metal nanoparticles deposited in regular arrays spaced at optical wavelengths support a resonance due to a coherent coupling between localized surface plasmon mode and lattice diffraction allowing for engineering of tunable devices for use in biological sensors, nanoantennae, and enhanced spectroscopy. Techniques such as electron beam lithography, focused ion beam lithography, nanosphere lithography, and nanoimprint lithography are used for fabrication but are limited by cost, device throughput, and small deposition. Polymer soft lithography and continuous dewetting of particles is a potentially viable alternative showing promise in all of those areas. This thesis developed the fabrication of a refined hydrophilic nanoimprinted …

Morphology Controlled Synthesis Of Copper Based Multimetallic Nanostructures And Their Electrocatalytic Properties For Methanol Oxidation Reaction, Leanne Elizabeth Mathurin

Graduate Theses and Dissertations

This research focuses on the development of shape-controlled synthesis of Cu NM, Cu-based bimetallic and trimetallic nanostructures, and their electrocatalytic properties for methanol oxidation reaction (MOR). Copper nanomaterials (Cu NM) with specific surface facets can tailor their catalytic activity. Understanding reagents responsible for Cu NM growth is important for morphology-controlled synthesis of the nanostructures. This research studies the halide influence on Cu NM growth and morphology in an oil-based synthesis. The morphology of the Cu NM varies with the halide type (i.e., Cl-, Br-, I-), and the halide concentration. Additionally, the type of Cu precursor also influenced the morphology of …

Exploring Thermoresponsive Affinity Agents To Enhance Microdialysis Sampling Efficiency Of Proteins, Thaddeus Vasicek

Graduate Theses and Dissertations

Affinity agents increase microdialysis protein relative recovery, yet they have not seen widespread use within the microdialysis community due to their additional instrumentation requirements and prohibitive cost. This dissertation describes new affinity agents for microdialysis that require no additional instrumentation to use, have nearly 100% particle recovery, are 7 times more cost efficient than alternatives, and have low specificity enabling their use for a wide variety of proteins. Initially gold nanoparticles were chosen as an affinity ligand support due to their high surface area/volume ratio and colloidal stability. Poly (N-isopropylacrylamide) was immobilized to the gold nanoparticles, which served to sterically …

Synthesis, Characterization, And Activity Of Co/Fe Alumina/Silica Supported Ft Catalysts And The Study Of Promoter Effect Of Ruthenium, Sunday Azubike Esumike

Doctoral Dissertations

The alumina and hybrid alumina-silica FT catalyst were prepared by one-step solgel/oil-drop methods using metal-nitrate-solutions (method-I), and nanoparticle-metaloxides (method-2). The nanoparticle-metal-oxides did not participate in solubility equilibria in contrast to metal nitrate in method-1 causing no metal ion seepage; therefore, method-2 yields higher XRF metal loading efficiency than method-1. The thermal analysis confirmed that the metal loading by method-1 and method-2 involved two different pathways. Method-1 involves solubility equilibria in the conversion of metal-nitrate to metal- hydroxide and finally to metal-oxide, while in method-2 nanoparticle-metal-oxide remained intact during sol-gel-oil-drop and calcination steps.

The alumina supported catalysts were dominated by γ-alumina …

Plasmon-Mediated Energy Conversion In Metal Nanoparticle-Doped Hybrid Nanomaterials, Jeremy Dunklin

Graduate Theses and Dissertations

Climate change and population growth demand long-term solutions for clean water and energy. Plasmon-active nanomaterials offer a promising route towards improved energetics for efficient chemical separation and light harvesting schemes. Two material platforms featuring highly absorptive plasmonic gold nanoparticles (AuNPs) are advanced herein to maximize photon conversion into thermal or electronic energy. Optical extinction, attributable to diffraction-induced internal reflection, was enhanced up to 1.5-fold in three-dimensional polymer films containing AuNPs at interparticle separations approaching the resonant wavelength. Comprehensive methods developed to characterize heat dissipation following plasmonic absorption was extended beyond conventional optical and heat transfer descriptions, where good agreement was …