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In Vacuo Fabrication And Electronic Structure Characterization Of Atomic Layer Deposition Thin Films, Michael Schaefer

USF Tampa Graduate Theses and Dissertations

Improvement of novel electronic devices is possible by tailor-designing the electronic structure at device interfaces. Common problems observed at interfaces are related to unwanted band alignment caused by the chemical diversity of interface partners, influencing device performance negatively. One way to address this problem is by introducing ultra-thin interfacial dipole layers, steering the band alignment in a desired direction. The requirements are strict in terms of thickness, conformity and low density of defects, making sophisticated deposition techniques necessary. Atomic layer deposition (ALD) with its Ångstrom-precise thickness control can fulfill those requirements.

The work presented here encompasses the implementation of an …

Erratum To: Zn (Ii) And Cu (Ii) Adsorption And Retention Onto Iron Oxyhydroxide Nanoparticles: Effects Of Particle Aggregation And Salinity, Rebecca B. Chesne, Christopher S. Kim

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

In the original version of this article errors in Figs. 5 and 9 were identified by the authors. The corrected figures are given.

Electrochemical Characterization Of Self-Assembled Monolayers On Gold Substrates Derived From Thermal Decomposition Of Monolayer-Protected Cluster Films, Michael C. Leopold, Tran T. Doan, Melissa J. Mullaney, Andrew F. Loftus, Christopher M. Kidd

Chemistry Faculty Publications

Networked films of monolayer-protected clusters (MPCs), alkanethiolate-stabilized gold nanoparticles, can be thermally decomposed to form stable gold on glass substrates that are subsequently modified with self-assembled monolayers (SAMs) for use as modified electrodes. Electrochemical assessment of these SAM-modified gold substrates, including double-layer capacitance measurements, linear sweep desorption of the alkanethiolates, and diffusional redox probing, all show that SAMs formed on gold supports formed from thermolysis of MPC films possess substantially higher defect density compared to SAMs formed on traditional evaporated gold. The density of defects in the SAMs on thermolyzed gold is directly related to the strategies used to assemble …

Polymer Additives Effects On Structure And Dynamics, Adam Eugene Imel

Doctoral Dissertations

This dissertation presents work that expands the understanding of the effect additives have on the structure and dynamics of a polymer matrix. Polymer additives are molecules, nanoparticles or fibers that are added to a polymer to modify the properties of the host polymer. Due to the vast amount of additives available, our studies were limited to C₆₀ (C60), soft polystyrene nanoparticles, and poly(ethylene oxide).

The first part of this project examined the influence that C₆₀ nanoparticles have on the assembly of polyacrylonitrile using small angle and wide-angle x-ray scattering techniques and viscometry. The addition of C₆₀ (C60) …

Optical And Sensing Properties Of Various Shaped Gold Nanoplates And Highly Controlled Asymmetric Gold Nanoplate/Nanosphere Coupled Assemblies., Aiqin Fang

Electronic Theses and Dissertations

With the development of a strategy to correlate the dark-field light scattering spectra of individual nanostructures with scanning electron microscopy (SEM) and atomic force microscopy (AFM) images of the same nanostructures, we were able to investigate several interesting optical properties of Au nanoplates (NPs) and asymmetrically-coupled Au nanospheres (NSs) attached to Au NPs with a high level of control. The light scattering spectra of the NP/NS coupled structures depend strongly on the location of NS attachment on the NP. Attachment of multiple NSs at the edge/vertex sites leads to a unique synergistic effect. In contrast to the uniform distribution of …

Tin Nanoparticles Encapsulated In Hollow Tio2 Spheres As High Performance Anode Materials For Li-Ion Batteries, Xiang Pan

Theses and Dissertations

Tin, an anode material with a high capacity for lithium-ion batteries, has poor cyclic performance because of the high volume expansion upon lithiation. Based on a literature review of the applications of lithium-ion batteries and current research progress of the tin-based anode materials for lithium-ion batteries, we developed a method to synthesize hollow TiO2 spheres with tin nanoparticles anchored on the inner surface of the TiO2 shell. Such a unique tin/TiO2 composite alleviates the volume change of tin–based anode materials in charge-discharge processes. SnCl2·2H2O (Tin (II) chloride dihydrate) and titanium (IV) isopropoxide (TIPT) were used as the Sn source and …

The Quantum Efficiency Of Cdse Semiconducting Nanocrystals, Charles Bledsoe

Undergraduate Theses

CdSe molecules are semiconducting nanocrystals that absorb visible light and emit broad wavelengths of light in response. They utilize electromagnetic radiation not only for emitting broad wavelengths of visible light, but for fluorescence, conducting electricity, and vibrational relaxation. The Thermal Lensing technique (TL) can be used to study the lifetimes of the excited state transitions and the various nonradiative processes molecules can undergo in order to better understand the excited state dynamics of semiconducting nanocrystals, and in turn, better understand how these molecules may be applied in solar cells, lasers, and fluorescence labeling. Using known methods, four samples of CdSe …

Synthesis And Functionalization Of Fluorescent Quantum Dot Bioconjugates For Cellular Imaging Of Directed Gene Therapy, Jason Matthew Davis

MSU Graduate Theses

Herein, I optimize a method for synthesis and bioconjugation of water-soluble, fluorescent CdSe/ZnS quantum dots (QDs) for targeted cellular delivery of DNA. Core CdSe QDs were synthesized in high temperature organic solvents and passivated with a ZnS shell to increase quantum yield. The fluorescent QD nanoparticles were made water-soluble by enveloping them with an amphiphilic polymer. These aqueous nanoparticles were functionalized with tertiary amines to impart a positive charge, allowing electrostatic binding to negatively-charged DNA. The conjugated QDs were characterized using zeta potential and electrophoresis to gauge their ability to electrostatically bind DNA. The QDs were further modified by conjugation …

Synthesis And Application Of Pdib Nanostructures In Solar Cells, John T. Ferguson

Mahurin Honors College Capstone Experience/Thesis Projects

Perylenediimide bridged silsesquioxane (PDIB) nanoparticles were synthesized by sol-gel processes as described by the Stöber method. These particles were synthesized homogeneously from solution and with the use of silica nanoparticles and bipyridine iodide bridged silsesquioxane (BPIB) nanoparticles as nucleation sites. The morphology of the resulting particles was confirmed by TEM and the presence of PDI confirmed by UV spectroscopy. Although further research will test all of the particles across a range of concentrations and sizes, the silica nucleated PDIB nanoparticles were analyzed in the active layer of bulk heterojunction organic photovoltaic devices in conjunction with P3HT polymer. Devices with the …

Facile Method For Large Scale Alignment Of One Dimensional Nanoparticles And Its Biomedical Application, Sheng Feng

Theses and Dissertations

Topographical cues can profoundly affect cellular behaviors. This thesis investigate how to utilize the topographical cues generated by two techniques, flow assembly and electrospinning, to regulate cellular behaviors.

First of all, a facile and robust method to align one-dimensional (1D) nanoparticles (NPs) in large scale has been developed. Using flow assembly, representative rod-like nanoparticles, including tobacco mosaic virus (TMV), gold nanorods and bacteriophage M13, have been aligned inside capillaries by controlling flow rate and substrate surface properties. The properties of 1D NPs, such as stiffness and aspect ratio, play a critical role in the alignment. Furthermore, these hierarchically organized structures …

Novel Magnetic And Optical Properties Of Sn1−XZnXO2 Nanoparticles, Nevil A. Franco, Kongara M. Reddy, Josh Eixenberger, Dmitri A. Tenne, Charles B. Hanna, Alex Punnoose

Physics Faculty Publications and Presentations

In this work, we report on the effects of doping SnO₂ nanoparticles with Zn²⁺ ions. A series of ∼2–3 nm sized Sn_1−x Zn_xO₂ crystallite samples with 0 ≤ x ≤ 0.18 were synthesized using a forced hydrolysis method. Increasing dopant concentration caused systematic changes in the crystallite size, oxidation state of Sn, visible emission, and band gap of SnO₂ nanoparticles. X-ray Diffraction studies confirmed the SnO₂ phase purity and the absence of any impurity phases. Magnetic measurements at room temperature showed a weak ferromagnetic behavior characterized by an open hysteresis loop. Their …

Computational Prediction And Rational Design Of Novel Clusters, Nanoparticles, And Solid State Materials, Alexander S. Ivanov

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The prediction of structure at the atomic level is one of the most fundamental challenges in materials science. Indeed, the structure is arguably the most important piece of information about a material, as it determines pretty much all properties of a material. Knowing the structure, one can analyze a large number of properties of a material, even before it is synthesized – the crucial importance of structure prediction for computational molecular design. This dissertation describes the technique of reliable theoretical predictions and presents the results on the successfully predicted unusual clusters, nanoparticles and solid state materials. The major part of …

Nanoparticle Plasmonics: Going Practical With Transition Metal Nitrides, U. Guler, V. M. Shalaev, A. Boltasseva

U. Guler

Promising designs and experimental realizations of devices with unusual properties in the field of plasmonics have attracted a great deal of attention over the past few decades. However, the high expectations for realized technology products have not been met so far. The main complication is the absence of robust, high performance, low cost plasmonic materials that can be easily integrated into already established technologies such as microelectronics. This review provides a brief discussion on alternative plasmonic materials for localized surface plasmon applications and focuses on transition metal nitrides, in particular, titanium nitride, which has recently been shown to be a …

Biophysical Interaction Between Nanoparticles And Biomolecules, Slaven Radic

All Dissertations

In the last two decades nanotechnology market has undergone remarkable growth. Breakthroughs in nanomaterial synthesis increased diverse nanomaterials production and subsequently their application. Owing to its large surface to volume ratio and remarkable physical properties not seen in the bulk materials, nanoparticles are finding emerging use in industry and medicine. Hence, it is expectable that at some point these nanomaterials will end up released into the environment and interact with bio systems. The purpose of this dissertation is to elicit implications of nanomaterial transformation once it gets inside biological milieu.

Conjugated Polymer Nanoparticles For Biological Labeling And Delivery, Eladio A. Mendez

FIU Electronic Theses and Dissertations

Cancer remains one of the world’s most devastating diseases, with more than 10 million new cases every year. However, traditional treatments have proven insufficient for successful medical management of cancer due to the chemotherapeutics’ difficulty in achieving therapeutic concentrations at the target site, non-specific cytotoxicity to normal tissues, and limited systemic circulation lifetime. Although, a concerted effort has been placed in developing and successfully employing nanoparticle(NP)-based drug delivery vehicles successfully mitigate the physiochemical and pharmacological limitations of chemotherapeutics, work towards controlling the subcellular fate of the carrier, and ultimately its payload, has been limited. Because efficient therapeutic action requires drug …

Dihydrolipoic Acid Conjugated Carbon Dots Accelerate Human Insulin Fibrillation, Sheba J. Kuruvilla, Shanghao Li, Lorenzo Sansalone, Blake Fortes, Ian Zheng, Patricia Blackwelder, Cyrus Pumilia, Miodrag Micic, Jhony Orbulescu, Roger M. Leblanc

Marine & Environmental Sciences Faculty Articles

Protein fibrillation is believed to play an important role in the pathology and development of several human diseases, such as Alzheimer’s disease, Parkinson’s disease and type 2 diabetes. Carbon dots (CDs), as a new type of nanoparticle have recently been extensively studied for potential biological applications, but their effects on protein fibrillation remain unexplored. In reality, any application in biological systems will inevitably have “contact” between proteins and CDs. In this study, human insulin was selected as a model protein to study the effects of CDs on protein fibrillation, as proteins may share a common mechanism to form fibrils. Hydrophobic …

Analysis Of The Surface Density And Reactivity Of Perfluorophenylazide And The Impact On Ligand Immobilization, Gilad Zorn, David G. Castner, Anuradha Tyagi, Xin Wang, Hui Wang, Mingdi Yan

Chemistry Faculty Publications and Presentations

Perfluorophenylazide (PFPA) chemistry is a novel method for tailoring the surface properties of solid surfaces and nanoparticles. It is general and versatile, and has proven to be an efficient way to immobilize graphene, proteins, carbohydrates, and synthetic polymers. The main thrust of this work is to provide a detailed investigation on the chemical composition and surface density of the PFPA tailored surface. Specifically, gold surfaces were treated with PFPA-derivatized (11-mercaptoundecyl) tetra(ethylene glycol) (PFPA-MUTEG) mixed with 2-[2-(2-mercaptoethoxy)ethoxy]ethanol (MDEG) at varying solution mole ratios. Complementary analytical techniques were employed to characterize the resulting films including Fourier transform infrared spectroscopy to detect fingerprints …

Real-Time Mri-Guided Catheter Tracking Using Hyperpolarized Silicon Particles, Nicholas Whiting, Jingzhe Hu, Jay V. Shah, Maja C. Cassidy, Erik Cressman, Niki Zacharias Millward, David G. Menter, Charles M. Marcus, Pratip K. Bhattacharya

Nicholas Whiting

Controllable Synthesis Of Concave Cubic Gold Core-Shell Nanoparticles For Plasmon-Enhanced Photon Harvesting, Yang Bai, Teera Butburee, Hua Yu, Zhen Li, Rose Amal, Gao Qing (Max) Lu, Lianzhou Wang

Australian Institute for Innovative Materials - Papers

Well-defined core-shell nanoparticles (NPs) containing concave cubic Au cores and TiO₂ shells (CA@T) were synthesized in colloidal suspension. These CA@T NPs exhibit Localized Surface Plasmon Resonance (LSPR) absorption in the NIR region, which provides a unique property for utilizing the low energy range of the solar spectrum. In order to evaluate the plasmonic enhancement effect, a variety of CA@T NPs were incorporated into working electrodes of dye-sensitized solar cells (DSSCs). By adjusting the shell thickness of CA@T NPs, the plasmonic property can be tuned to achieve maximum photovoltaic improvement. Furthermore, the DSSC cells fabricated with the CA@T NPs exhibit …

Ac-Susceptibility And Epr Investigations Of Superspin Dynamics In Magnetite Nanoparticles, Alex D. Price

Open Access Theses & Dissertations

In this investigation we use two complementary techniques to distinguish between superparamagnetic blocking (SPB) and superspin-glass (SSG) freezing phenomena in magnetite nanoparticles. While these manifestations of the superspin dynamics are fundamentally different, they have similar "signatures", especially in dc-magnetization experiments. Even if ac-susceptibility measurements are employed, careful use of mathematical models to analyze the data are needed to uncover which type of phenomena (SPB or SSG freezing) occurs within the material. Yet, by utilizing electron paramagnetic resonance (EPR) on a 10 nm Fe3O4 nano-powder as well as on a ferrofluid (based on the same nanoparticle ensemble) we found a very …

Nanoscale Gumbos: Size-Control, Characterization, And Applications As Enantioselective Molecularly Imprinted Polymers And Fluorescent Materials, Suzana Hamdan

LSU Doctoral Dissertations

Nanomaterials derived from a group of uniform materials based on organic salts (GUMBOS) have been introduced into the scientific literature through many analytical, biological, and technological applications. These nanomaterials, referred to as nanoGUMBOS, have been shown to display a number of interesting properties including fluorescence, magnetism, tumor targeting, and optoelectronic properties. Herein, we present major studies on nanoGUMBOS including synthesis and size-control, chiral molecular imprinting in polymers, as well as investigation of optical properties and quantum yield of fluorescent semiconductor-based nanoGUMBOS. Various strategies were introduced for production of well-defined nanoGUMBOS. Specifically, several methods based on sonochemistry, microwave, cyclodextrin, and surfactant-assisted …

Comparative Metal Oxide Nanoparticle Toxicity Using Embryonic Zebrafish, Leah C. Wehmas, Catherine Anders, Jordan Chess, Alex Punnoose, Cliff B. Pereira, Juliet A. Greenwood, Robert L. Tanguay

Physics Faculty Publications and Presentations

Engineered metal oxide nanoparticles (MO NPs) are finding increasing utility in the medical fields as anticancer agents. Before validation of in vivo anticancer efficacy can occur, a better understanding of whole-animal toxicity is required. We compared the toxicity of seven widely used semiconductor MO NPs made from zinc oxide (ZnO), titanium dioxide, cerium dioxide and tin dioxide prepared in pure water and in synthetic seawater using a five-day embryonic zebrafish assay. We hypothesized that the toxicity of these engineered MO NPs would depend on physicochemical properties. Significant agglomeration of MO NPs in aqueous solutions is common making it challenging to …

A Theoretical And Experimental Investigation Of The Physical And Chemical Properties Of Solid Nanoscale Interfaces, Jeronimo Matos

Electronic Theses and Dissertations

With the emerging interest in nanoscale materials, the fascinating field of surface science is rapidly growing and presenting challenges to the design of both experimental and theoretical studies. The primary aim of this dissertation is to shed some light on the physical and chemical properties of selected nanoscale materials at the interface. Furthermore, we will discuss the effective application of cutting edge theoretical and experimental techniques that are invaluable tools for understanding the systems at hand. To this effect, we use density functional theory (DFT) with the inclusion of van der Waals (vdW) interactions to study the effect of long-range …

Additional Results For "Joint Entropy Of Continuously Differentiable Ultrasonic Waveforms" [J. Acoust. Soc. Am. 133(1), 283-300 (2013)], M S. Hughes, J N. Marsh, S A. Wickline, John E. Mccarthy

Mathematics Faculty Publications

Previous results on the use of joint entropy for detection of targeted nanoparticles accumulating in the neovasculature of MDA435 tumors [Fig. 7 of M. S. Hughes et al., J. Acoust. Soc. Am. 133, 283–300 (2013)] are extended, with sensitivity improving by nearly another factor of 2. This result is obtained using a “quasi-optimal” reference waveform in the computation of the joint entropy imaging technique used to image the accumulating nanoparticles.

Designing Core/Alloy Nanoparticles By Manipulation Of Interfacial Oxidation And Atomic Diffusion, Rahiem Davon Slaton

Dissertations - ALL

Alloying presents a unique opportunity to combine the chemical and physical properties of two or more metals into one material. This phenomenon can also be used for multi-metallic nanoparticles (NPs), where in conjunction with the size effects induced by quantum confinement, new properties or phase behavior can emerge. The properties of nanoalloys are highly dependent on their composition and morphology, which are contingent upon the method in which they are synthesized. Finding ways to control, or even design, the composition and morphology of nanoalloys could potentially open the door for a standardized approach for creating nanomaterials with unique and desirable …

Characterization Of Metallic And Semimetallic Oxide Nanoparticles In Industrial Wastewater And Associated Toxicity, Gary Roth

Legacy Theses & Dissertations (2009 - 2024)

Engineered nanomaterials (ENMs) play an increasing role in manufacturing and consumer products. Currently, there is no standard approach to studying ENM toxicity, and a growing body of literature suggests that ENMs may have toxicity differing from similar compounds in bulk or dissolved form. I examined ENMs used in the semiconductor manufacturing process called chemical-mechanical planarization (CMP) for their properties, removal in the wastewater treatment system (WWT), in-vitro toxicity, and location post-inhalation in-vivo. It was found that ENMs in CMP slurries have morphology determined by their elemental composition, but assessment of size and concentration can differ substantially between accepted techniques. Particles …

One-Pot Synthesis Of Ultra-Small Magnetite Nanoparticles On The Surface Of Reduced Graphene Oxide Nanosheets As Anodes For Sodium-Ion Batteries, Shaohua Zhang, Weijie Li, Bien Tan, Shulei Chou, Zhen Li, S X. Dou

Australian Institute for Innovative Materials - Papers

Nanocomposites with ultra-small magnetite (Fe₃O₄) nanoparticles (approx. 3 nm) uniformly anchored on the surfaces of reduced graphene oxide (RGO) nanosheets were successfully synthesized for anodes in sodium-ion batteries by a novel single-step high-temperature coprecipitation approach. The best electrode delivers a reversible Na⁺ storage capacity of 204 mA h g^-1 with excellent capacity retention, i.e., 98% of the second-cycle value was retained after 200 cycles.

Can The Wet - State Conductivity Of Hydrogels Be Improved By Incorporation Of Spherical Conducting Nanoparticles?, Katharina Schirmer, Cody Wright, Holly Warren, Brianna C. Thompson, Anita F. Quigley, Robert M. I Kapsa, Gordon G. Wallace

Australian Institute for Innovative Materials - Papers

In nerve and muscle regeneration applications, the incorporation of conducting elements into biocompatible materials has gained interest over the last few years, as it has been shown that electrical stimulation of some regenerating cells has a positive effect on their development. A variety of different materials, ranging from graphene to conducting polymers, have been incorporated into hydrogels and increased conductivities have been reported. However, the majority of conductivity measurements are performed in a dry state, even though material blends are designed for applications in a wet state, in vivo environment. The focus of this work is to use polypyrrole nanoparticles …

A New Strategy For Achieving A High Performance Anode For Lithium Ion Batteries-Encapsulating Germanium Nanoparticles In Carbon Nanoboxes, Dan Li, Hongqiang Wang, Hua-Kun Liu, Zaiping Guo

Australian Institute for Innovative Materials - Papers

A novel strategy to improve the electrochemical performance of a germanium anode is proposed via encapsulating germanium nanoparticles in carbon nanoboxes by carbon coating the precursor, germanium dioxide cubes, and then subjecting them to a reduction treatment. The complete and robust carbon boxes are shown to not only provide extra void space for the expansion of germanium nanoparticles after lithium insertion but also offer a large reactive area and reduced distance for the lithium diffusion. Furthermore, the thus-obtained composite, composed of densely stacked carbon nanoboxes encapsulating germanium nanoparticles (germanium at carbon cubes (Ge at CC)), exhibits a high tap density …

Effect Of Acrylic Acid Feed Contents Of Microgels On Catalytic Activity Of Silver Nanoparticles Fabricated Hybrid Microgels, Zahoor Hussain Farooqi, Shanza Rauf Khan, Robina Begum, Farah Kanwal, Ahsan Sharif, Ejaz Ahmed, Shumaila Majeed, Kiran Ejaz, Aysha Ijaz

Turkish Journal of Chemistry

We synthesized poly(N-isopropylacrylamide-co-acrylic acid) microgels with 1, 3, 5, and 7 mol percentage of acrylic acid. Silver nanoparticles were fabricated inside these microgels at room temperature. Pure microgels were characterized by Fourier transform infrared (FTIR) spectroscopy and dynamic light scattering (DLS). Hybrid microgels were characterized by UV-Visible spectroscopy. The size of the silver nanoparticles increased with an increase in the content of acrylic acid. Catalytic activity of these hybrid microgels was investigated using UV-Visible spectrophotometry. Induction time decreased from 8.8 to 2.6 min and the value of apparent rate constant decreased from 0.226 to 0.109 min^{-1}, when the content of …