Physical Sciences and Mathematics Commons^™

Formation And Analysis Of Zinc Oxide Nanoparticles And Zinc Oxide Hexagonal Prisms And Optical Analysis Of Cadmium Selenide Nanoparticles, Jared M. Hancock

Theses and Dissertations

In this dissertation, methods to synthesize ZnO are reported. First, zinc oxide nanoparticles were synthesized with small amounts of transition metal ions to create materials called dilute magnetic semiconductors (DMS). We employed a low temperature sol-gel method that produces ZnO nanoparticles of reproducible size and incorporates cobalt, nickel, and manganese ions into the nanoparticles. Conditions were controlled such that a range of amounts of Co, Ni, and Mn were incorporated. The incorporation was tracked by color changes in the white ZnO powder to blue for Co, green for Ni and yellow for Mn. XRD measurements showed the nanoparticles were on …

Laser Vaporization Methods For The Synthesis Of Metal And Semiconductor Nanoparticles; Graphene, Doped Graphene And Nanoparticles Supported On Graphene, Parichehr Afshani

Theses and Dissertations

The major objective of the research described in this dissertation is the development of new laser vaporization methods for the synthesis of metal and semiconductor nanoparticles, graphene, B- and N-doped graphene, and metal and semiconductor nanoparticles supported on graphene. These methods include the Laser Vaporization Controlled Condensation (LVCC) approach, which has been used in this work for the synthesis of: (1) gold nanoparticles supported on ceria and zirconia nanoparticles for the low temperature oxidation of carbon monoxide, and (2) graphene, boron- and nitrogen-doped graphene, hydrogen-terminated graphene (HTG), metal nanoparticles supported on graphene, and graphene quantum dots. The gold nanoparticles supported …

Size-Based Separation Of Bioparticles Using Planar Nanofluidic Devices, Jie Xuan

Theses and Dissertations

Nanofluidic devices are structures having at least one dimension in the submicron range, which is of the same order of magnitude as the sizes of biomolecules and bioparticles such as proteins and viruses. As a result, size-selective separations are important applications for nanofluidics. Well-defined micro or nano device structures fabricated via micromachining have greatly reduced sample consumption and enabled separations in a parallel fashion, promising significant speed and resolution advantages over conventional size separation techniques, such as gel electrophoresis and size exclusion chromatography. In collaboration with others, I have developed a size separation method using nanofluidic devices consisting of an …

Electrochemiluminescence Of Thienyltriazoles, Iridium Complexes, Au25 Clusters And Pbs Nanoparticles, Kalen N. Swanick

Electronic Thesis and Dissertation Repository

Electrogenerated chemiluminescence or electrochemiluminescence (ECL), produces light in the vicinity of a working electrode by the excited species of a luminophore formed via electron transfer between radical cations and anions, which are electrogenerated. In order for the ECL system to be efficient, the radicals must be stable in solution. This can be enhanced by adding co-reactants such as benzoyl peroxide (BPO) and tri-n-propylamine (TPrA) that produce strong oxidizing or reducing radicals upon redox reactions. ECL pairs electrochemical and spectroscopic methods and is a powerful analytical technique that is highly sensitive and selective.

A comprehensive, mechanistic study of ECL …

Polysaccharide-Based Nanocarriers For Improved Drug Delivery, Nan Zhang

Dissertations - ALL

The field of drug delivery has provided a solution to the limited efficacy and high toxicity of many drugs. Nano-sized drug carriers are popular because their size allows for selective accumulation in the diseased area. Polysaccharides are non-toxic and biodegradable natural polymers that can serve as the basis for these nano-sized carriers. Polysialic acid (PSA) is such a polysaccharide with strong hydrophilicity that may reduce uptake by the reticuloendothelial system and prolong drug circulation. In this study, we developed PSA-based nanocarriers, specifically micelles and nanoparticles, for improved drug delivery with improved efficacy and minimized toxicity. PSA-based micelle systems were developed …

Stability And Precipitation Of Diverse Nanoparticles, Chintal Desai

Dissertations

Nanotechnology is a rapidly growing industry that is exploiting the novel characteristics of materials manufactured at the nanoscale. Carbon based nanomaterials such as Carbon Nanotubes (CNTs) and Detonation Nanodiamond (DND) possess unique properties and find a wide range of industrial applications. With the advent of mass production of such materials, there is a possibility of contamination of water resources. Depending on the surface properties and structures, they might aggregate and settle down, or be dispersed and transported by the water. Therefore, there is a need to develop an understanding of the fate of such materials in aqueous media. The understanding …

Plasmonic Nanostructures For The Absorption Enhancement Of Silicon Solar Cells, Nathan Matthias Burford

Graduate Theses and Dissertations

In this work, computational investigation of plasmonic nanostructures was conducted using the commercial finite element electromagnetics solver Ansys® HFSS. Arrays of silver toroid nanoparticles located on the surface of an amorphous silicon thin-film absorbing layer were studied for particle sizes ranging from 20 nm to 200 nm in outer diameter. Parametric optimization by calculating an approximation of the photocurrent enhancement due to the nanoparticles was performed to determine optimal surface coverage of the nanoparticles. A comparison was made between these optimized nanotoroid arrays and optimized nanosphere arrays based on spectral absorption enhancement and potential photocurrent enhancement in an amorphous silicon …

Nanoparticle Filled Polymeric Systems For Gas Barrier And Flame Retardant Properties, Yingji Wu

Dissertations

Polymer composite gas barrier and fire retardant properties were studied in this investigation. An increase in the gas barrier property was observed by adding silicate nanotubes or clay nanoparticles into polymeric systems. Oxygen permeability, diffusivity, solubility and water vapor permeability were determined for polyimide/silicate nanocomposites with 0 to 9.99% (vol/vol) filler loading. Both oxygen and water vapor permeability for the system gradually decreased when adding increasing amounts of nanofiller up to 4.50% (vol/vol) and increase again after that. The permeability decrease was caused by both the diffusivity and solubility coefficient changes, although diffusivity (the tortuous factor) is the main reason …

The Effects Of Physicochemical Properties Of Ceo2 Nanoparticles On Toxicity To Soil Denitrification Processes, Jessica Dahle

All Theses

Due to the rise of nanotechnology in industry, the concentrations of engineered metal oxide nanoparticles being released to the environment are increasing daily. Cerium-based compounds such as nanoparticulate ceria (NP CeO2) have received much attention in the last several years due to their popular applications (e.g., mischmetal, pharmaceuticals, nanotechnology) in industrial and commercial uses. Like many emerging pollutants, NP CeO2 is often released to the environment, where its toxicological effects are not well known. Though several environmental exposure pathways have been identified for CeO2 NPs, a major route of NP introduction to the environment is via biosolids application to agricultural …

Study And Identification Of Environmental Nanoparticles In Governors State University (Gsu's) Agricultural Fields, Ekta Desai

All Capstone Projects

Main purpose of this project is to study nanoparticles in Governors State University’s agricultural field and design experimental protocol for the same. Nanoparticles have one dimension that measures between 1 - 100 nanometers or less. Nanoparticles are widely used in day to day life such as in medicines, textiles, manufacturing and cosmetics. Due to their wide use, they can enter environment through many ways such as accidental spills during handling. Waste water treatment plant disposal serves as a main source of their entrance into the environment. Analysis of nanoparticles in environmental samples presents a number of challenges, including separation and …

Light-Matter Interactions Of Plasmonic Nanostructures, Jennifer Reed

Electronic Theses and Dissertations

Light interaction with matter has long been an area of interest throughout history, spanning many fields of study. In recent decades, the investigation of light-matter interactions with nanostructures has become an intense area of research in the field of photonics. Metallic nanostructures, in particular, are of interest due to the interesting properties that arise when interacting with light. The properties are a result of the excitation of surface plasmons which are the collective oscillation of the conduction electrons in the metal. Since the conduction electrons can be thought of as harmonic oscillators, they are quantized in a similar fashion. Just …

Impact Of Cerium Oxide Nanoparticles On Cilantro (Coriandrum Sativum), Maria Isabel Morales

Open Access Theses & Dissertations

Studies have shown that plants exposed to ENPs suffer different types of stress. Other studies have revealed that plants can take up and accumulate CeO2 NPs without modification. Thus, these NPs could enter the food chain through edible plants, posing a threat for human health. Cilantro (Coriandrum sativum) is a worldwide culinary and medicinal plant consumed either as a fresh herb or a spice. In this research, cilantro plants were germinated and cultivated for 30 days in organic soil treated with CeO2 NPs at concentrations varying from 0 to 500 mg kg!1. Subsequently, plant organs were analyzed by using spectroscopic …

Two-Photon Microscopy Of Nanoparticles And Biotissues, Judith Noemi Rivera

Open Access Theses & Dissertations

Biomedical Imaging is an important tool in medical research and clinical practice. From understanding the fundamental processes involved in our biological makeup to its use in diagnostics in helping determine what ails us, the advancements in imaging and microscopy have helped shape our view of the world and nature. Microscopy in particular is often used to study the smallest of cells and their dynamical properties while attempting to minimally change the sample being studied. My research objective is largely divided into two parts. The first part consists of designing a video-rate raster scanning two-photon microscope that is faster than current …

The Effect Of Nanostructure On The Electrical Properties Of Metal Oxide Materials, Philip Zachary Rice

Legacy Theses & Dissertations (2009 - 2024)

Resistive random access memory (ReRAM) is a potential replacement technology for Flash and other memory implementations. Advantages of ReRAM include increased scalability, low power operation, and compatibility with silicon semiconductor manufacturing. Most of the ReRAM devices described to date have utilized thin film based metal oxide dielectrics as a resistive switching matrix. The goal of this dissertation project has been to investigate the resistive switching behavior of nanoparticulate metal oxides and to develop methods to utilize these materials in ReRAM device fabrication. To this end, nanoparticles of TiO₂ and HfO₂ were synthesized under a variety of conditions resulting …

Luminescence Studies : Part I. Lanthanide Nanogumbos Part Ii. Near Infrared Photothermal Nanogumbos, Jonathan Carver Dumke

LSU Doctoral Dissertations

Group of Uniform Materials Based on Organic Salts (GUMBOS) are a class of molten salts that have been focused to be specifically tailored towards applications. Primitively, from Davy to Walden molten salts were desirable for organic synthesis due to the properties. GUMBOS have been synthesized into nanoparticles (nanoGUMBOS) by various methods to be used for lanthanide luminescence and hyperthermal cancer therapeutics. Lanthanide photochemistry has been frequently studied for its high luminescence intensity, narrow emission band, and stable luminescent lifetime decay. Aerosol-derived europium nanoGUMBOS were characterized using electron microscopy (39.5 ± 8.4 nm), XPS, and spectroscopic techniques. Spectroscopic measurements indicated intense …

Analysis Of Protein Aggregates And Synthetic Nanoparticles Using Capillary Electrophoresis With Light Scattering And Fluorescence Detection, Suresh Chandra Regmi

LSU Doctoral Dissertations

The goal of the research presented in this dissertation is to develop capillary electrophoresis (CE) based analysis techniques for the characterization of individual particles including amyloid beta (Aâ) peptide aggregates and to apply these methods to study the aggregation of Aâ peptides. Protein self-assembly into ordered aggregates is a common and important process in normal biological function, but this process is also involved in several diseases. Amyloid beta peptide aggregation is linked to Alzheimer’s disease. Thioflavin T (ThT) has been used as a fluorescent probe for the detection of Aâ aggregation. Based on previous observations of false positive fluorescent signals …

Single-Crystal Metal Oxides And Supported Metal Nanoclusters As Model Catalyst Sytems, Matthew C. Patterson

LSU Doctoral Dissertations

We have investigated the morphology and electronic structure of two basic classes of systems: metal oxide surfaces that catalyze the formation of environmentally persistent free radicals (EPFRs) from aromatic precursors, and Au and Cu nanoparticles that may be suitable catalysts for the catalytic oxidation of CO or hydrogenation of CO2. First, we examine the adsorption behavior of phenol on rutile TiO2(110) and ultrathin films of alumina prepared on a NiAl(110) substrate. Electron paramagnetic resonance studies show that exposure of both γ-alumina and titania powder to phenol at 250°C results in the formation of persistent phenoxyl radicals. EELS studies of phenol …

Abiotic Reduction Of Nitrite And Nitrate By Nanoscale Chemogenic Magnetite: Pathways For Significant Greenhouse Gas Production, Adam Charles Burdsall

Browse all Theses and Dissertations

The biogeochemical cycling of nitrogen in terrestrial systems is a major source of nitrous oxide (N₂O), which is among key greenhouse gases (GHG). While biotic processes are commonly accepted as the major drivers of N₂O production, the role of abiotic processes is less understood, and their importance may be underestimated. This study investigates abiotic reactions in the formation and breakdown of N trace gases, including nitric oxide (NO) and nitrous oxide (N₂O) by naturally occurring nanoscale magnetite in soil as denitrification (reduction of nitrite) intermediates. Nitrogen biogeochemical cycling has been studied extensively with respect …

Synthesis And Properties Of Polymer Nanocomposites With Tunable Electromagnetic Response, Kristen Lee Stojak

USF Tampa Graduate Theses and Dissertations

Multifunctional polymer nanocomposites (PNCs) are attractive for the design of tunable RF and microwave components such as flexible electronics, attenuators, and antennas due to cost-effectiveness and durability of polymeric matrices. In this work, three separate PNCs were synthesized. Magnetite (Fe3O4) and cobalt ferrite (CFO) nanoparticles, synthesized by thermal decomposition, were used as PNC fillers. Polymers used in this work were a commercial polymer provided by the Rogers Corporation (RP) and polyvinylidene fluoride (PVDF). PNCs in this thesis consist of Fe3O4 in RP, CFO in RP, and Fe3O4 in PVDF. Characterization techniques for determining morphology of the nanoparticles, and their resulting …

Model Pt- And Pd-Based Electrocatalysts For Low Temperature Fuel Cells Applications, Selasi Ofoe Blavo

USF Tampa Graduate Theses and Dissertations

In the search for alternative energy technologies, low temperature fuel cells continue to feature as technologies with the most promise for mass commercialization. Among the low temperature fuel cells, alkaline and proton exchange membrane fuel cells are the most popular. Alkaline fuel cells have typically been used for water generation as well as auxiliary power for space shuttles. Their bulkiness however makes them undesirable for other applications, especially in automobiles, where there is a great demand for alternative technologies to internal combustion engines. Proton exchange membrane fuel cells on the other hand possess numerous qualities including their compact size, high …

Interaction Of Ceo2 And Zno Nanoparticles Towards The Symbiotic Association Of Alfalfa (Medicago Sativa) And Sinorhizobium Meliloti In Soil, Susmita Bandyopadhyay

Open Access Theses & Dissertations

The production of engineered nanoparticles (ENPs) has rapidly increased due to their wide range of applications in the field of electronics, medicine, chemistry and biology. Consequently, concerns have risen about the environmental release and potential negative impact of NPs. A few reports have described the effects of TiO2 NPs and quantum dots upon nitrogen fixing bacteria. However, the understanding of the interaction of NPs in plant-microbe interface (symbiotic association), like alfalfa (Medicago sativa L.)-Sinorhizobium meliloti, is still in its infancy. Alfalfa is the world's most important forage crop. It grows in association with S. meliloti, which is very important in …

Determination Of The Effects Of Zno And Ceo2 Nanoparticles In Mesquite (Prosopis Juliflora) And Soybean (Glycine Max): Synchrotron And Spectroscopic Approaches, Jose Angel Hernandez Viezcas

Open Access Theses & Dissertations

The rapid growth of nanotechnology is exposing the environment to abnormal concentrations of engineered nanoparticles (NPs). There is concern about the unknown consequences of NPs on the environment and human health. This Dissertation has relied significantly on Synchrotron and other spectroscopic techniques to give insights on the effects, speciation and distribution of two metal oxide nanoparticles (ZnO, CeO2) on two plant species (Mesquite and Soybean). We evaluated the effects of ZnO (10 nm) and CeO2 (8 nm) NPs on a plant species native to the semi-arid regions of North America, Mesquite (Prosopis juliflora velutina). Mesquite plants grown in hydroponic culture …