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Full-Text Articles in Nanoscience and Nanotechnology

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 …


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.


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 …


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 …


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, …


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 …