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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 …

Processing, Structure, And Properties Of Nanoparticle Reinforced Nonwoven Sandwich Composites, Josh Griffith Fogle

Doctoral Dissertations

Shockwaves produced from ballistic impacts and improvised explosive devices are capable of causing severe internal trauma to soldiers. Current antiballistic materials give adequate protection to soldiers from high velocity impacts, however they are insufficient at absorbing and dissipating shockwave energy generated by these impacts and explosive blasts. The goal of this research was to develop shockwave absorbing protective materials which can be used as liners in conjunction with current antiballistic materials by reinforcing thermoplastic polyurethane nonwovens with high modulus nanoparticles

To determine the appropriate TPU for the application, a series of TPUs of shore hardness ranging from 60D to 85A …

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 …

Coalescence Kinetics Of Lipid Based Bicelles, Andrew Hu

Master's Theses

Uniform nanodisc structures can be self assembled from mixtures of different phospholipids. This study focuses on the theoretical and experimental growth kinetics of phospholipid based nanodiscs. Motivation for this project comes from the nanodisc’s small size and their potential use as a carrier for drug delivery. It was observed that at high total lipid concentration the nanodiscs are stable at approximately 10 nm in radius and can remain stable for a long period of time. However, growth of these nanodiscs are observed at relatively low total lipid concentration. The observed growth mechanism is not well understood. In this thesis dynamic …

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 …

Batch And Continuous Production Of Stable Dense Suspensions Of Drug Nanoparticles In A Wet Stirred Media Mill, Afolawemi Afolabi

Dissertations

One way to improve the bioavailability of poorly water-soluble drugs is to reduce particle size of drug crystals down to nanoscale via wet stirred media milling. An increase in total surface area per mass loading of the drug and specific surface area as well as reduced external mass transfer resistance allow a faster dissolution of the poorly-water soluble drug from nanocrystals. To prevent aggregation of nanoparticles, polymers and surfactants are dissolved in water acting as stabilizers via adsorption onto the drug crystals.

In the last two decades, ample experimental data were generated in the area of wet stirred media milling …

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 …

Designingtargeted F4/80 Antibody Coated Tnf-Α Sirna Loaded Nanoparticles: A Novel Therapeutic Approach To Treat Inflammatory Bowel Disease, Poonam Rakhya

Biology Theses

ABSTRACT

Today, increasing evidences of systemic side effects with the treatments available for IBD limit their therapeutic outcomes. The challenge is to target anti-TNF-α agent to the inflamed tissue. Here, we have demonstrated that TNF-α siRNA can be efficiently loaded into F4-80 antibody (Ab) coated PLA-PEG-Mal nanoparticles (NPs) to target colonic macrophages (MPs). The NPs were characterized for particle size, cytotoxicity, binding characteristics, etc. These NPs are ~600 nm in diameter, non-cytotoxic, and are efficiently taken up by MPs inhibiting TNF-α secretion by the MPs in vitro. In vivo, the release of TNFa siRNA loaded inside F4/80 Ab coated NPs …

Green Manufacturing Of Nanoparticles For Biomedical Applications, Sijia Yi

Doctoral Dissertations

The vast majority of nanomaterials are chemically synthesized, a costly process, that is environmentally risky, and the produced nanoparticles are potentially toxic to patients. Nature-based nanomaterials, however, are proving to be much more biocompatible with lower environmental toxicity. Even though a variety of natural nanomaterials have been designed, fabrication technologies for the desired natural nanoparticles with reproducible quality, high productivity and low cost remain a challenge. My objective has been to establish strategies for the isolation, purification and characterization of nanoparticles using a production system based on green tea and fungus (Arthrobotrys oligospora) and also to develop new …

Effect Of Relative Humidity In High Temperature Oxidation Of Ceria Nanoparticles Coating On 316l Austenitic Stainless Steel, Luis Giraldez Pizarro

Theses and Dissertations

A solution of 20 wt. % colloidal dispersion of Cerium Oxide (CeO2) in 2.5% of acetic acid, was used for depositing a coating film on an austenitic stainless steel 316L. Cerium compounds have been distinguished as potential corrosion inhibitors in coatings over several alloys. The oxidation behavior of the cerium oxide coating on 316L austenitic stainless steel alloy was evaluated in dry and humid environments, the weight changes (W/A) was monitored as a function of time using a custom built Thermogravimetrical Analysis (TGA) instrument at temperatures of 750C, 800C and 850C, and different relative humidity levels (0%, 10% and 20%) …

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 …

Efficacy Of Gold Silica Nanoshells And Gold Nanorods For Photothermal Therapy Of Human Glioma Spheroids, Suyog Jung Chhetri

UNLV Theses, Dissertations, Professional Papers, and Capstones

Gold-based nanoparticles including gold-silica nano-spheres and gold nano-rods have been investigated for a number of therapeutic and diagnostic applications. The ability of these nanoparticles to convert light into heat energy makes them particularly appealing for photothermal therapy in which cancer cells are destroyed via light-induced heat generation. The overall objective of the study is to compare the efficacy of gold-silica nano-spheres and gold nano-rods in an in vitro system consisting of human brain tumor (glioma) spheroids.

Delivery of the nanoparticles to the spheroids was accomplished using murine macrophages. Nanoparticles (spheres or rods) were incubated with macrophages for 24 hours. Thereafter, …

Selective Nanoparticles For Antimicrobial Therapies And Mri Diagnostics, Mark Andrew Hoppens

LSU Master's Theses

Early diagnosis and treatment of an infection and the selectivity of the treatment method are three parameters, which if optimized will greatly enhance a patient’s prognosis. Thus these three components have been, and continue to be extensively studied. Advances in biosynthesis and nanofabriciation have provided researchers with new tools with which to improve diagnostic and therapeutic techniques. Of these, inorganic nanoparticles (NPs) have shown great promise. Metallic nanoparticles have been demonstrated to successfully serve as antimicrobials, platforms for the transportation of therapeutic molecules, CT and MRI contrast agents, and thermal ablation. The recent paradigm of theranostics proposes substances that serve …

Dielectrophoretic Precipitation Of Airborne Particles., Joseph D. Duff

Electronic Theses and Dissertations

Experimental and numerical modeling studies of particle separation from a gas stream using a dielectric force have shown that dielectrophoresis is an appropriate mechanism for the filtration of a particulate matter from a particle laden gas stream. Dielectrophoresis technology has the ability to produce high filtration efficiency with highly restive particles. This is the first known work producing a device that demonstrates that dielectrophoresis will separate particles from this type of fluidic system. The testing was conducted using frequencies on the order of 60 Hz, 15 kHz, and DC. The voltage ranged from 100V to 300V and the fluid velocity …

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 …

Tuning The Performance Of Nanocarbon-Based Gas Sensors Through Nanoparticle Decoration, Shumao Cui

Theses and Dissertations

Tin dioxide (SnO₂) is a well–known gas sensing material, but it becomes sensitive only at elevated temperatures (e.g., above 200 °C). Nanoparticles (NPs) combined with nanocarbons, such as carbon nanotubes (CNTs) and graphene, form a new class of hybrid nanomaterials that can exhibit fascinating gas sensing performance due to tunable electron transfer between NPs and nanocarbons induced by gas adsorption. Indeed, sensors made of SnO₂ NPs&ndascoated CNTs have shown outstanding room–temperature sensing performance to various gases, including those that are undetectable by either SnO₂ or CNTs alone.

The objectives of this dissertation study are to synthesize …

Optimal Solution Based Plasmonic Interfaces For Photocurrent Enhancement In Silicon-On-Insulator Devices, Miriam Israelowitz

Electrical Engineering and Computer Science – Theses

Renewable energy sources are a vital topic to the future of growing industrialized nations. Solar cells are a popular potential technology to become a major source of energy supply, with Silicon (Si) being the most common solar cell semiconductor material. To address the cost of bulk Si, thin film amorphous Silicon (a-Si) solar cell technology was developed. The drawback to using thin film a-Si solar cells is the reduction in power efficiency compared to bulk Si cells. In this work we explore the use of local plasmon resonance and nanoparticle interfaces to enhance photocurrent within thin film Si. Silver (Ag) …

Production Of High Yield Gold/Gold-Sulfide Nanoparticles Via Cellulose Membrane., Kurtis T. James

Electronic Theses and Dissertations

The properties of gold nanoparticles (GNP) holds promising potential for drug delivery, diagnostics, plasmonic photothermal therapy of diseases, electronics, catalysis, and photovoltaics (Liu et al., 2006; Huang et al., 2003; Thompson, 2007; Atwater and Polman, 2010). This field is growing at a fast pace with the demand for GNPs ever increasing with slow progress on development of synthesis techniques. The objective of this study was to develop a new synthesis technique that produces gold/gold sulfide (GGS) nanoparticles with a high yield. This process can control the equilibrium shift of the surface plasmon resonance (SPR) of the nanoparticles (Patel, 2012). The …

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 …

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 …

Hydrogen (H2) Sensing And Catalysis With Organic-Stabilized Pd And Pd Alloy Nanoparticles., Monica Moreno

Electronic Theses and Dissertations

This dissertation shows the hydrogen reactivity and stability of solid-state films and solutions of nanoparticles (NPs) for potential applications in hydrogen sensing and homogeneous catalysis of organic reactions. Mainly, this dissertation describes 1) the chemical synthesis of Pd and PdAg nanoparticles coated with various organic ligands and with different metal compositions, 2) the stability of solutions containing Pd and PdAg NPs in the presence of hydrogen, 3) the hydrogen sensing properties of films of NPs deposited onto Au microelectrodes, and 4) the evaluation of the catalytic activity of Pd and PdAg NPs for hydrogenation/isomerization of allyl alcohol. We chemically synthesized …

Development Of Novel Layered Nanoparticles For More Efficient Cancer Treatment., Thomas A. Priest

Electronic Theses and Dissertations

Cancer is the second-most leading cause of death in the United States, with 1.66 million new cases expected to be diagnosed and over 580,000 Americans expected to die of cancer in 2013 alone. (American Cancer Society 2013) Current treatments result in damage to the healthy tissues and incomplete resections of solid tumors, but by harnessing nanotechnology, more effective treatments can be constructed. Gold nanoshells present a promising option for targeted cancer therapy. The anatomy of tumors causes the “enhanced permeability and retention” effect, which means that nano-scale particles will extravasate from the bloodstream and accumulate in the tumors. However, small …

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 …

Application Of Mixed Iron Oxides In Subsurface Remediation Technologies, Saidur Rahman Chowdhury

Electronic Thesis and Dissertation Repository

Heavy metal contamination of soil and groundwater has been a concern in water supply and public health in many countries where the water supply system draws primarily from groundwater. In the present study, mixed maghemite-magnetite nanoparticles have been used as adsorbents for Cr(VI), As and Cd(II) removal. From the study, it is apparent that the removal of Cr(VI ), Cd(II) and As(V) by mixed iron oxide nanoparticles depends on pH, temperature, contact time, solid/liquid ratio and initial concentration of heavy metals. The results showed that Cr(VI) adsorption on mixed maghemite-magnetite was dependent on solution pH between 3 and 6. Theoretical …

Elucidation Of Peptide Sequence Effects That Control The Activity, Size, And Function Of Nanoparticles, Ryan Coppage

Open Access Dissertations

Bio-inspired nanoparticle catalysis offers the opportunity to improve on current catalytic standards with respect to turnover efficiency, organic solvent use, and thermal activation. Unfortunately, projected energy demands will soon outweigh our fuel supplies. The task of creating multifunctional catalysts that both lower thermal activation and possess a number of functions in aqueous conditions is daunting. Similar to these needs, nature has evolved to create a wide range of highly specialized catalytic processes, which incorporate inorganic materials, take place in ambient temperatures, and in an aqueous environment. These specialized biological systems provide inspiration, but are not applicable to current needs. Exploitation …

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 …

Computational Analysis To Enhance Laminar Flow Convective Heat Transfer Rate In An Enclosure Using Aerosol Nanofluids, Andrew Hudson

Electronic Theses and Dissertations

The current research intends to provide a starting point to effectively model aerosol heat transfer in a narrow, enclosed body. This research can lead to future modeling of nano fluids including their heat transfer characteristics and erosion effects on the walls of an enclosure. The model was developed using ICEM CFD for the mesh and FLUENT for the fluid flow modeling. Six different aspect ratio enclosures were developed to study the effects of varying aspect ratio. The natural convection of air was developed first to establish the appropriateness of the models being used. A mesh check was performed using one …

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 …

Development Of Vapor Deposited Silica Sol-Gel Particles For A Bioactive Materials System To Direct Osteoblast Behavior, Katherine Lynn Snyder

Dissertations, Master's Theses and Master's Reports - Open

Tissue engineering and regenerative medicine have emerged in an effort to generate replacement tissues capable of restoring native tissue structure and function, but because of the complexity of biologic system, this has proven to be much harder than originally anticipated. Silica based bioactive glasses are popular as biomaterials because of their ability to enhance osteogenesis and angiogenesis. Sol-gel processing methods are popular in generating these materials because it offers: 1) mild processing conditions; 2) easily controlled structure and composition; 3) the ability to incorporate biological molecules; and 4) inherent biocompatibility. The goal of this work was to develop a bioactive …

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 …