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2010

Nanoparticles

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Full-Text Articles in Engineering

Studies On The Preparation And Luminescence Properties Of Cadmium Selenide Quantum Dots, Their Immobilization, And Applications., Travis Justin Heath Dec 2010

Studies On The Preparation And Luminescence Properties Of Cadmium Selenide Quantum Dots, Their Immobilization, And Applications., Travis Justin Heath

Electronic Theses and Dissertations

Quantum dots are semiconductive particles whose properties are highly influenced by the presence of at least one electron. Cadmium selenide quantum dots were synthesized via colloidal synthesis. Contrary to previous preparations, more focus was placed on the temperature rather than the duration of time at which they form. A series of colored solutions were obtained because the excited quantum dots of various sizes emitted specific wavelengths of light. The emission spectra showed that the temperature-dependent quantum dots were successfully synthesized. The quantum dots were also immobilized on various surfaces, and the luminescence properties were examined. The quantum dots that were …


Intracellular Localisation, Geno- And Cytotoxic Response Of Poly N-Isopropylacrylamide (Pnipam) Nanoparticles To Human Keratinocyte (Hacat) And Colon Cells (Sw 480), Pratap Naha, Kunal Bhattacharya, Tiziana Tenuta, Kenneth Dawson, Iseult Lynch, Amaya Gracia, Fiona Lyng, Hugh Byrne Oct 2010

Intracellular Localisation, Geno- And Cytotoxic Response Of Poly N-Isopropylacrylamide (Pnipam) Nanoparticles To Human Keratinocyte (Hacat) And Colon Cells (Sw 480), Pratap Naha, Kunal Bhattacharya, Tiziana Tenuta, Kenneth Dawson, Iseult Lynch, Amaya Gracia, Fiona Lyng, Hugh Byrne

Articles

PNIPAM nanoparticles, with and without a covalentlylinked fluorescent label, were prepared by a free radical polymerisation technique. The cyto and genotoxicity of PNIPAM nanoparticles were analysed in two representative mammalian cell lines, SW480, a colon, and HaCaT, a dermal cell line. Physical characterisation in terms of particle size and zeta potential of the PNIPAM nanoparticles was carried out both in aqueous solution and in the appropriate cell culture media. Uptake and colocalisation of fluorescently labelled PNIPAM nanoparticles was monitored in both cell lines using confocal laser scanning microscopy. Genotoxicity analysis using the Comet assay was performed in both cell lines …


Providing A Theoretical Basis For Nanotoxicity Risk Analysis Departing From Traditional Physiologically-Based Pharmacokinetic (Pbpk) Modeling, Dirk P. Yamamoto Sep 2010

Providing A Theoretical Basis For Nanotoxicity Risk Analysis Departing From Traditional Physiologically-Based Pharmacokinetic (Pbpk) Modeling, Dirk P. Yamamoto

Theses and Dissertations

The same novel properties of engineered nanoparticles that make them attractive may also present unique exposure risks. But, the traditional physiologically-based pharmacokinetic (PBPK) modeling assumption of instantaneous equilibration likely does not apply to nanoparticles. This simulation-based research begins with development of a model that includes diffusion, active transport, and carrier mediated transport. An eigenvalue analysis methodology was developed to examine model behavior to focus future research. Simulations using the physicochemical properties of size, shape, surface coating, and surface charge were performed and an equation was determined which estimates area under the curve for arterial blood concentration, which is a surrogate …


Programmable Periodicity Of Quantum Dot Arrays With Dna Origami Nanotubes, Hieu Bui, Craig Onodera, Carson Kidwell, Yerpeng Tan, Elton Graugnard, Wan Kuang, Jeunghoon Lee, William B. Knowlton, Bernard Yurke, William L. Hughes Sep 2010

Programmable Periodicity Of Quantum Dot Arrays With Dna Origami Nanotubes, Hieu Bui, Craig Onodera, Carson Kidwell, Yerpeng Tan, Elton Graugnard, Wan Kuang, Jeunghoon Lee, William B. Knowlton, Bernard Yurke, William L. Hughes

Materials Science and Engineering Faculty Publications and Presentations

To fabricate quantum dot arrays with programmable periodicity, functionalized DNA origami nanotubes were developed. Selected DNA staple strands were biotin-labeled to form periodic binding sites for streptavidin-conjugated quantum dots. Successful formation of arrays with periods of 43 and 71 nm demonstrates precise, programmable, large-scale nanoparticle patterning; however, limitations in array periodicity were also observed. Statistical analysis of AFM images revealed evidence for steric hindrance or site bridging that limited the minimum array periodicity.


Phenomena Characterization Of Energy Materials By X-Ray Absorption Spectroscopy, Ming-Yao Cheng, Chun-Jen Pan, Ju-Hsiang Cheng, Bing-Joe Hwang Aug 2010

Phenomena Characterization Of Energy Materials By X-Ray Absorption Spectroscopy, Ming-Yao Cheng, Chun-Jen Pan, Ju-Hsiang Cheng, Bing-Joe Hwang

Journal of Electrochemistry

The aim of this review is to introduce the characterization of energy materials by X-ray absorption spectroscopy (XAS) . This technique allows us to probe changes in the valance state and the local environment of the targeted element in the active material; thereby,leading to a better understanding of its electrochemical behavior,and hopefully showing the way to improved performance. Here,electrocatalysts for fuel cells and active electrode materials for Li-ion batteries are taken as the examples that illustrate the capability of XAS and allow observation and theory to be correlated with electrochemical phenomena.


Fabrication Of Fluorescent Nanoparticle-Polymer Composites For Photoactive-Based Materials, Brett Ellerbrock Aug 2010

Fabrication Of Fluorescent Nanoparticle-Polymer Composites For Photoactive-Based Materials, Brett Ellerbrock

All Theses

Nanocomposites of nanoparticles dispersed throughout a polymer matrix have been studied to great length to improve the overall polymer properties. These enhancements are observed in the thermal, physical, and/or optical characteristics. Being able to harness nanoparticles in such a way may help improve fiber technology into the 21st century.
This work was geared toward synthesizing rare earth doped lanthanum fluoride (LaF3) nanoparticles because good separation in the absorption and emission bands of the material and it fluoresces in the visible to near-infrared range. Terbium ions were added to a LaF3 crystal because of their distinct visible green …


Effect Of Particle Properties And Light Polarization On The Plasmonic Resonances In Metallic Nanoparticles, U. Guler, R. Turan Jul 2010

Effect Of Particle Properties And Light Polarization On The Plasmonic Resonances In Metallic Nanoparticles, U. Guler, R. Turan

U. Guler

The resonance behavior of localized surface plasmons in silver and gold nanoparticles was studied in the visible and near-infrared regions of the electromagnetic spectrum. Arrays of nano-sized gold (Au) and silver (Ag) particles with different properties were produced with electron-beam lithography technique over glass substrates. The effect of the particle size, shape variations, period, thickness, metal type, substrate type and sulfidation were studied via transmission and reflectance measurements. The results are compared with the theoretical calculations based on the DDA simulations performed by software developed in this study. We propose a new intensity modulation technique based on localized surface plasmons …


Experiments And Modelling Of Micro-Jet Assisted Fluidization Of Nanoparticles, J. Ruud Van Ommen, David M. King, Alan Weimer, Robert Pfeffer, Berend Van Wachem May 2010

Experiments And Modelling Of Micro-Jet Assisted Fluidization Of Nanoparticles, J. Ruud Van Ommen, David M. King, Alan Weimer, Robert Pfeffer, Berend Van Wachem

The 13th International Conference on Fluidization - New Paradigm in Fluidization Engineering

The fluidization of nanoparticle agglomerates can be largely improved by using downward pointing micronozzles, creating a high-velocity jet, as experimentally shown. By discrete particle simulations – treating the agglomerates as single particles – we show that the main reason is probably the reduction of the agglomerate size by agglomerate-agglomerate collisions.


Fluidization Of Nanopowders: Experiments, Modeling, And Applications, J. Ruud Van Ommen, Robert Pfeffer May 2010

Fluidization Of Nanopowders: Experiments, Modeling, And Applications, J. Ruud Van Ommen, Robert Pfeffer

The 13th International Conference on Fluidization - New Paradigm in Fluidization Engineering

Nanopowders are applied in a wide range of processes, and their use continues to increase. Fluidization is one of the best techniques available to disperse and process nanoparticles. However, nanoparticles cannot be fluidized individually; they fluidize as very porous agglomerates. Often, it is needed to apply an assisting method, such as vibration or microjets, to obtain proper fluidization. In this paper, we give a brief review of the developments in nanopowder fluidization.


A Reactive Molecular Dynamics Simulation Of The Silica-Water Interface, Joseph C. Fogarty, Hasan Metin Aktulga, Ananth Y. Grama, Adri C. T. Van Duin, Sagar A. Pandit May 2010

A Reactive Molecular Dynamics Simulation Of The Silica-Water Interface, Joseph C. Fogarty, Hasan Metin Aktulga, Ananth Y. Grama, Adri C. T. Van Duin, Sagar A. Pandit

PRISM: NNSA Center for Prediction of Reliability, Integrity and Survivability of Microsystems

We report our study of a silica-water interface using reactive molecular dynamics. This first-of-its-kind simulation achieves length and time scales required to investigate the detailed chemistry of the system. Our molecular dynamics approach is based on the ReaxFF force field of van Duin [J. Phys. Chem. A 107, 3803 (2003)]. The specific ReaxFF implementation (SERIALREAX) and force fields are first validated on structural properties of pure silica and water systems. Chemical reactions between reactive water and dangling bonds on a freshly cut silica surface are analyzed by studying changing chemical composition at the interface. In our simulations, reactions involving silanol …


Sorption Of Bovine Serum Albumin On Nano And Bulk Oxide Particles, Lei Song Jan 2010

Sorption Of Bovine Serum Albumin On Nano And Bulk Oxide Particles, Lei Song

Masters Theses 1911 - February 2014

Manufactured oxide nanoparticles (NPs) have large production and widespread applications, which will inevitably enter the environment. NPs can interact with proteins in living beings due to the fact that NPs can transport into blood or across cell membranes into cells. Conformational change of protein molecules after sorption on oxide NPs has been reported. Therefore, it is important to understand the adsorption mechanism of protein onto oxide NPs surfaces. Although few works have reported protein adsorption behaviors, a general systematic comparison of the effects of particle size and surface groups on protein adsorption by widely studied NPs still needs to be …


Synthesis, Structure, And Catalytic Properties Of Size-Selected Platinum Nanoparticles, Simon Armando Covone Jan 2010

Synthesis, Structure, And Catalytic Properties Of Size-Selected Platinum Nanoparticles, Simon Armando Covone

Electronic Theses and Dissertations

The use of heterogeneous catalysis is well established in chemical synthesis, energy, and environmental engineering applications. Supported Pt nanoparticles have been widely reported to act as catalysts in a vast number of chemical reactions. In this report, the performance of Pt/ZrO2 nanocatalyst for the decomposition of methanol, ethanol, 2-propanol, and 2-butanol is investigated. The potential of each alcohol for the production of H2 and other relevant products in the presence of a catalyst is studied. All the alcohols studied show some decomposition activity below 200°C which increased with increasing temperature. In all cases, high selectivity towards H2 formation is observed. …


Effects From Filtration, Capping Agents, And Presence/Absence Of Food On The Toxicity Of Silver Nanoparticles To Daphnia Magna, H. Joel Allen, Christopher A. Impellitteri, Dana A. Macke, J. Lee Heckman, Helen C. Poynton, James M. Lazorchak, Shekar Govindaswamy, Deborah L. Roose, Mallikarjuna N. Nadagouda Jan 2010

Effects From Filtration, Capping Agents, And Presence/Absence Of Food On The Toxicity Of Silver Nanoparticles To Daphnia Magna, H. Joel Allen, Christopher A. Impellitteri, Dana A. Macke, J. Lee Heckman, Helen C. Poynton, James M. Lazorchak, Shekar Govindaswamy, Deborah L. Roose, Mallikarjuna N. Nadagouda

United States Environmental Protection Agency: Staff Publications

Relatively little is known about the behavior and toxicity of nanoparticles in the environment. Objectives of work presented here include establishing the toxicity of a variety of silver nanoparticles (AgNPs) to Daphnia magna neonates, assessing the applicability of a commonly used bioassay for testing AgNPs, and determining the advantages and disadvantages of multiple characterization techniques for AgNPs in simple aquatic systems. Daphnia magna were exposed to a silver nitrate solution and AgNPs suspensions including commercially available AgNPs (uncoated and coated), and laboratory-synthesized AgNPs (coated with coffee or citrate). The nanoparticle suspensions were analyzed for silver concentration (microwave acid digestions), size …


Micro- To Macroscopic Observations Of Mnalpo-5 Nanocrystal Growth In Ionic-Liquid Media, Eng-Poh Ng Dr. Jan 2010

Micro- To Macroscopic Observations Of Mnalpo-5 Nanocrystal Growth In Ionic-Liquid Media, Eng-Poh Ng Dr.

Eng-Poh Ng

Micro- and macroscopic studies of nucleation and growth processes of MnAlPO-5 nanosized crystals under ionothermal synthesis conditions are reported herein. The samples treated at 150 8C were extracted from the reaction mixture at various stages of crystallization, and characterized by XRD; SEM; thermogravimetric analysis (TGA); 31P and 27Al solid-state magic angle spinning (MAS) NMR, Raman, UV/Vis, and X-ray fluorescence spectroscopy (XRF). The starting raw materials (alumina, manganese, and phosphorous) were dissolved completely in the ionic liquid and transformed into an amorphous solid after 5 h of ionothermal treatment. This amorphous solid then undergoes structural changes over the following 5–25 h, …


Preparation Of Titanium Dioxide Nanoparticles From Electrocoagulated Sludge Using Sacrificial Titanium Electrodes, H K. Shon, S Phuntsho, S Vigneswaran, Jaya Kandasamy, Long Nghiem, G J. Kim, J B. Kim, Jin-Ho Kim Jan 2010

Preparation Of Titanium Dioxide Nanoparticles From Electrocoagulated Sludge Using Sacrificial Titanium Electrodes, H K. Shon, S Phuntsho, S Vigneswaran, Jaya Kandasamy, Long Nghiem, G J. Kim, J B. Kim, Jin-Ho Kim

Faculty of Engineering - Papers (Archive)

A comprehensive investigation of electrocoagulation using sacrificial titanium (Ti) electrodes in wastewater was carried out. The effects of specific process variables, such as initial pH, mixing, current density, initial organic loading, and ionic/electrolyte strength were first optimized to produce recyclable Ti-based sludge. The sludge was incinerated at 600 °C to produce functional TiO2 photocatalyst. X-ray diffraction analysis revealed that TiO2 produced at optimum electrocoagulation conditions was mostly anatase structure. The specific surface area of the synthesized TiO2 photocatalyst was higher than that of the commercially available and widely used Degussa P-25 TiO2. Furthermore, energy dispersive …


Plasmon Enhanced Near-Field Interactions In Surface Coupled Nanoparticle Arrays For Integrated Nanophotonic Devices, Amitabh Ghoshal Jan 2010

Plasmon Enhanced Near-Field Interactions In Surface Coupled Nanoparticle Arrays For Integrated Nanophotonic Devices, Amitabh Ghoshal

Electronic Theses and Dissertations

The current thrust towards developing silicon compatible integrated nanophotonic devices is driven by need to overcome critical challenges in electronic circuit technology related to information bandwidth and thermal management. Surface plasmon nanophotonics represents a hybrid technology at the interface of optics and electronics that could address several of the existing challenges. Surface plasmons are electronic charge density waves that can occur at a metal-dielectric interface at optical and infrared frequencies. Numerous plasmon based integrated optical devices such as waveguides, splitters, resonators and multimode interference devices have been developed, however no standard integrated device for coupling light into nanoscale optical circuits …


Synthesis, Structural Characterization And Magnetic Properties Of Iron Boride Nanoparticles With Or Without Silicon Dioxide Coating, Mislav Mustapic, Damir Pajic, Nikolina Novosel, Emil Babic, Kreso Zadro, Marina Cindric, Josip Horvat, Zeljko Skoko, Mirjana Bijelic, Andrey Shcherbakov Jan 2010

Synthesis, Structural Characterization And Magnetic Properties Of Iron Boride Nanoparticles With Or Without Silicon Dioxide Coating, Mislav Mustapic, Damir Pajic, Nikolina Novosel, Emil Babic, Kreso Zadro, Marina Cindric, Josip Horvat, Zeljko Skoko, Mirjana Bijelic, Andrey Shcherbakov

Faculty of Engineering - Papers (Archive)

Nanoparticles of iron boride (Fe2B, Fe2B coated in SiO2, FexCo2xB coated in SiO2) were synthesized using the reduction of metal ions by sodium borohydride. X-ray diffraction confirms the amorphicity of the coated compounds and scanning electron microscope imaging revealed the nanoparticulated structure of all compounds. The splitting between zero-field-cooled and field-cooled temperature dependent magnetization curves point to the blocking of superparamagnetic particles magnetization. Magnetic hysteresis loops are however consistent with the combined effects of blocked superparamagnetic and ferromagnetic (multidomain) particles. The observed quite complex magnetic behaviour is in …


Antisense Silver Nanoparticles For Photo-Activated Gene Silencing, Paige Kathleen Brown Jan 2010

Antisense Silver Nanoparticles For Photo-Activated Gene Silencing, Paige Kathleen Brown

LSU Master's Theses

The unique properties of noble metal nanoparticles, which include tunable electronic and photonic characteristics, contribute to their potential as novel delivery vectors with enhanced drug stability, cell uptake, and photo-activated functionalities. Silver, as one of best surface-enhancing substrates available for bulk nanostructure synthesis, is a prime choice for investigations of metal nanohybrids as antisense therapy vehicles with special surface plasmon resonance (SPR) enabled functional attributes. The singular photonic properties of silver nanoparticles (SNPs) may contribute to ease of delivery confirmation and in situ photo-activation of protected cargo packed on particle surfaces. Here we show the synthesis and characterization of 40-80nm …


Microbial Reduction Of Uranium Under Iron- And Sulfate-Reducing Conditions: Effect Of Amended Goethite On Microbial Community Composition And Dynamics, H.S. Moon, L. Mcguinness, Ravi K. Kukkadapu, A.D. Peacock, John Komlos, L.J. Kerkhof, P.E. Long, Peter R. Jaffe Jan 2010

Microbial Reduction Of Uranium Under Iron- And Sulfate-Reducing Conditions: Effect Of Amended Goethite On Microbial Community Composition And Dynamics, H.S. Moon, L. Mcguinness, Ravi K. Kukkadapu, A.D. Peacock, John Komlos, L.J. Kerkhof, P.E. Long, Peter R. Jaffe

US Department of Energy Publications

There is a growing need for a better understanding of the biogeochemical dynamics involved in microbial U(VI) reduction due to an increasing interest in using biostimulation via electron donor addition as a means to remediate uranium contaminated sites. U (VI) reduction has been observed to be maximized during iron-reducing conditions and to decrease upon commencement of sulfate-reducing conditions. There are many unknowns regarding the impact of iron/sulfate biogeochemistry on U(VI) reduction. This includes Fe(III) availability as well as the microbial community changes, including the activity of iron-reducers during the uranium biostimulation period even after sulfate reduction becomes dominant. Column experiments …


Far-Field Optical Nanoscopy Based On Continuous Wave Laser Stimulated Emission Depletion, C. Kuang, Wei Zhao, Guiren Wang Jan 2010

Far-Field Optical Nanoscopy Based On Continuous Wave Laser Stimulated Emission Depletion, C. Kuang, Wei Zhao, Guiren Wang

Faculty Publications

Stimulated emission depletion (STED) microscopy is one of the breakthrough technologies that belong to far-field optical microscopy and can achieve nanoscale spatial resolution. We demonstrate a far-field optical nanoscopy based on continuous wave lasers with different wavelengths, i.e., violet and green lasers for excitation and STED, respectively. Fluorescent dyes Coumarin 102 and Atto 390 are used for validating the depletion efficiency. Fluorescent nanoparticles are selected for characterizing the spatial resolution of the STED system. Linear scanning of the laser beams of the STED system along one line of a microscope slide, which is coated with the nanoparticles, indicates that a …


Mesoporous Tin Oxide As An Oxidation-Resistant Catalyst Support For Proton Exchange Membrane Fuel Cells, Peng Zhang, Sheng-Yang Huang, Branko N. Popov Jan 2010

Mesoporous Tin Oxide As An Oxidation-Resistant Catalyst Support For Proton Exchange Membrane Fuel Cells, Peng Zhang, Sheng-Yang Huang, Branko N. Popov

Faculty Publications

Mesoporous catalyst support based on tin oxide (SnO2) is synthesized with high surface area of 205 m2 g−1 and with narrow pore size distribution. Modified polyol method is used to deposit platinum on SnO2. The physical properties of the support and the SnO2-supported Pt catalyst (Pt/SnO2) are characterized by using the Brunauer, Emmett, and Teller method, X-ray diffraction, and transmission electron microscopy. The electrochemical stability and durability of the Pt/SnO2 catalyst are investigated by the accelerated stress tests proposed by the U.S. Department of Energy. Pt/SnO2 catalyst exhibits …


Itraconazole Loaded Poly (Lactic-Co-Glycolic) Acid Nanoparticles For Improved Antifungal Activity, Nipur Rajan Patel Jan 2010

Itraconazole Loaded Poly (Lactic-Co-Glycolic) Acid Nanoparticles For Improved Antifungal Activity, Nipur Rajan Patel

LSU Master's Theses

PLGA (polylactic-co-glycolic acid) nanoparticles containing the hydrophobic antifungal Itraconazole (ITZ) were developed to address the need for more efficient means of treating fungal infections. PLGA-ITZ nanoparticles were synthesized using an oil-in-water emulsion evaporation method. The nanoparticles morphology (TEM), size and size distribution, zeta potential (DLS), encapsulation efficiency (UV-VIS), release profile, and antifungal activity were characterized. The blank NPs and loaded PLGA-ITZ NPs were spherical with diameters of 201±5 nm, 232±1 nm and 223±36 nm at 0%, 12.5% and 25% loadings, respectively. All synthesized particles measured a negative zeta potential ranging from -28 to -33 mV. The maximum encapsulation efficiency of …