Nanoscience and Nanotechnology Commons^™

Pulsed Laser Coating Of Bioceramic (Hap) And Niti Nanoparticles On Metallic Implants, Aayush Goswami, Gary J. Cheng

The Summer Undergraduate Research Fellowship (SURF) Symposium

This research deals with increasing the biocompatibility of the bio implants which have a global market valued more than $94.1 billion . The surface of the metal alloys used for the bone implants need to be coated with bio compatible materials like HAp(Hydroxyapatite), graphene, etc. in order to promote the growth of cells(osteoblasts) on the surface of the implants. Various techniques like plasma spray coating, ion beam sputter coating, etc. have been used before to coat such materials on a substrate, however these have faced problems of coating quality. In order to perfect this coating, that is make it more …

Metal-Assisted Etching Of Silicon Molds For Electroforming, Ralu Divan, Dan Rosenthal '14, Karim Ogando, Leonidas E. Ocola, Daniel Rosenmann, Nicolaie Moldovan

Student Publications & Research

Ordered arrays of high-aspect-ratio micro/nanostructures in semiconductors stirred a huge scientific interest due to their unique one-dimensional physical morphology and the associated electrical, mechanical, chemical, optoelectronic, and thermal properties. Metal-assisted chemical etching enables fabrication of such high aspect ratio Si nanostructures with controlled diameter, shape, length, and packing density, but suffers from structure deformation and shape inconsistency due to uncontrolled migration of noble metal structures during etching. Hereby the authors prove that a Ti adhesion layer helps in stabilizing gold structures, preventing their migration on the wafer surface while not impeding the etching. Based on this finding, the authors demonstrate …

Plasmonics Resonance Enhanced Active Photothermal Effects In Aluminum Nanoenergetics For Propulsion Applications, Jacques Abboud

Doctoral Dissertations

In this dissertation, aluminum nanoparticles (Al NPs) are shown capable to on-demand enhance and control the local photothermal energy deposition, both spatially and temporally, via active photothermal effects initiated by the localized surface plasmon resonance (LSPR) phenomenon, and amplified by the Al exothermal oxidation reactions. Experiments in dry and wet environments along with computational modeling of the photothermal process are very desirable for gaining fundamental understanding, ignition optimization and parameter exploration.

Combined phenomena of motion and ignition of Al NPs are explored first in this study. Both resulting from exposing a pile of the nanoenergetics in hand to a single …

Fluorescence Characterization Of Quantum Dots For Use As Biomarkers, Logan M. Grimes

Materials Engineering

Fluorescence profiles of quantum dots (QDs) were characterized to select the ideal QDs for encapsulation in phospholipids for use as biomarkers to selectively adhere to cancer cells. QDs were synthesized and extracted 0, 30, 60, and 90 seconds after precursor compounds were mixed. These extractions were isolated by extraction time. Portions from each vial were coated in a zinc sulfide shelling procedure, leaving at least half of the QD solution unshelled. These samples were characterized over four days to monitor fluctuations in fluorescence. This was done utilizing an Ocean Optics spectrometer in conjunction with Spectra Suite software. The central wavelength, …

Application Of Quantum Dots Onto Glass Wafers As A Feasibility Test For The Spectral Down Conversion Of Uv Light For Solar Cells, Anthony Fong

Materials Engineering

Quantum dots have the ability to convert high energy photons into multiple lower energy photons. Down conversion of such high energy photons from sources such as UV light can be beneficial for applications on solar cells which waste much of the energy in the form of thermalization. To test this theory, a solar cell was hooked up to an Amprobe Solar Analyzer and tests were run to compare power output with and without the presence of quantum dots. Additionally, quantum dots were spin coated onto a glass wafer to determine its adhesion ability. Spectrometer readings were taken of the wafer …

Modeling Complex Properties Of Ferroelectric Nanocomposites, Raymond T. Walter

Raymond Walter

No abstract provided.

Micro-Mechanical Assessment Of The Local Plastic Strain Invoked During A Splined Mandrel Flow Forming Operation, Meysam Haghshenas

Electronic Thesis and Dissertation Repository

Splined Mandrel Flow Forming (SMFF) is a metal spinning operation that involves the application of high multiaxial compressive stress states to invoke large plastic flow in the work piece. This allows for essentially one-step fabrication of complex internally-splined shapes. In this research project, the equivalent plastic strain, invoked throughout bcc (1020 steel) and fcc (5052 and 6061 aluminum alloys, pure copper, and 70/30 brass) samples, that were made by SMFF, was measured. The objective of the research were to measure the to obtain data on the effect of microstructure and mechanical parameters on the flow formability of ductile bcc and …

Mild Yet Phase-Selective Preparation Of Tio2 Nanoparticles From Ionic Liquids – A Critical Study, Tarek Alammar, Heshmat Noei, Yuemin Wang, Anja V. Mudring

Anja V. Mudring

The phase selective synthesis of nanocrystalline TiO2, titania, in ionic liquids (ILs) is explored. The influence not only of the IL but also of the Ti-precursor, pH, and temperature is investigated. Sonochemical synthesis, microwave synthesis and conventional heating are compared. In the case of Ti(OiPr)4 (OiPr ¼ isopropyl) as the Ti-source the ILs [C4mim][Tf2N] (1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)amide), [C3mimOH][Tf2N] (1-(3-hydroxypropyl)-3-methylimidazolium bis(trifluoromethanesulfonyl)amide), [C4Py]- [Tf2N] (butylpyridinium bis(trifluoromethanesulfonyl)amide), [N1888][Tf2N] (methyltrioctylammonium bis- (trifluoromethanesulfonyl)amide), and [P66614][Tf2N] (tetradecyltrihexyl phosphonium bis(trifluoromethanesulfonyl) amide) led at ambient temperature to TiO2 in the form of anatase. The morphology of nano-anatase is controlled by the IL cation. Anatase nanospheres with a crystal size …

Interface-Assisted Ionothermal Synthesis, Phase Tuning, Surface Modification And Bioapplication Of Ln3+-Doped Nagdf4 Nanocrystals, Qiang Ju, Paul S. Campbell, Anja V. Mudring

Anja V. Mudring

Phase-selective synthesis of trivalent lanthanide-doped NaGdF4 nanocrystals, capped by ionic liquid cations bearing long alkyl chains, succeeded via a one-step interface-assisted ionothermal route. Owing to the existence of an interface formed between hydrophobic ionic liquids and ethylene glycol, selectively either pure cubic or hexagonal phase NaGdF4 could be obtained by changing the amount of the added surfactant, polyethyleneimine. By doping various trivalent lanthanide cations, multicolor emissions under excitation by a single wavelength could be achieved. The nanocrystals can be surface derivatized by an amphiphilic polymer and endowed with functional groups that allow the particles to not only be dispersed in …

Phase And Morphology Selective Interface-Assisted Synthesis Of Highly Luminescent Ln3+-Doped Nagdf4 Nanorods, Anja V. Mudring, Qiang Ju

Anja V. Mudring

Making use of the multifunctional properties of ionic liquids by employing them as a fluoride resource and hydrophilic phase, we have grown small, monodisperse, highly luminescent Ln3+-doped NaGdF4 nanorods at the interface between octadecene and the reactive ionic liquid 1-butyl-3-methylimidazolium tetrafluoroborate. The obtained nanocrystals could further be endowed with functional groups and rendered water dispersible, which allows them to be used for biodetection.

White-Light-Emitting Single Phosphors Via Triply Doped Laf3 Nanoparticles, Chantal Lorbeer, Anja V. Mudring

Anja V. Mudring

The production of high-quality phosphors for white-emitting applications is an important goal for the settlement of light-emitting diodes (LEDs) in the market and households. Single phosphors directly yielding white emission are advantageous in comparison to a mixture of individual red, green, and blue phosphors as these are hampered by reabsorption of the blue light. Here, a combined approach to uniform, nanoscale particles as single-white-emitting phosphor is realized via an ionic-liquid-based synthesis. LaF3 particles codoped with various amounts of Tm3+, Tb3+, and Eu3+ were synthesized, and their structural, morphological, and optical properties were studied. Small particles with a mean size of …