Nanoscience and Nanotechnology Commons^™

Properties Of Titanium Dioxide Nanoparticles Aquesous Dispersions Stabilized By Anionic Surfactants, Anita Vuchkovska

Theses and Dissertations

The stability of titanium dioxide nanoparticles dispersed in aqueous solutions with and without anionic surfactants was investigated as a function of phase separation (sedimentation), particle size at the age of 33 and 303 days, polydispersity at 33 and 303 days, and zeta potential. Mechanical energy in the form of homogenization or mixing with propeller blade mixer was used to wet out the titanium dioxide (TiO2) nanoparticles in the aqueous media and this process was evaluated for the capability of developing a stable dispersion. The ultrasonic waves were used as a second step to form stable dispersions. The research results indicated …

Subwavelength Engineering Of Silicon Photonic Waveguides, Farhan Bin Tarik

All Dissertations

The dissertation demonstrates subwavelength engineering of silicon photonic waveguides in the form of two different structures or avenues: (i) a novel ultra-low mode area v-groove waveguide to enhance light-matter interaction; and (ii) a nanoscale sidewall crystalline grating performed as physical unclonable function to achieve hardware and information security. With the advancement of modern technology and modern supply chain throughout the globe, silicon photonics is set to lead the global semiconductor foundries, thanks to its abundance in nature and a mature and well-established industry. Since, the silicon waveguide is the heart of silicon photonics, it can be considered as the core …

Control Mechanisms For Adaptive Nanoscale Devices, David Arredondo

Nanoscience and Microsystems ETDs

Nanotechnology promises to revolutionize many areas of applied science including materials, synthetic biology, and medicine. Devices may consist of solution-phase information processing systems or molecular robots. Of particular interest are DNA-based systems due to their composability and relatively simple interactions that are suited to bottom-up design. This work introduces high-level designs of robust control mechanisms for nanoscale devices with immediate applications in molecular computing, synthetic biology, and DNA robotics.

Nanoscale systems are dominated by probabilistic chemical behavior, so engineers must take careful consideration to produce predictable systems. Probabilistic behavior in chemical reaction networks (CRNs) yields deterministic evolution of species concentrations …

Physiologically-Based Pharmacokinetics Modeling Of Colloidal Nanoparticles, Anh-Dung Le

Nanoscience and Microsystems ETDs

Physiologically-based Pharmacokinetics (PBPK) modeling—a mechanistic mathematical tool to predict biodistribution to inform drug development, requires knowledge of the physico-chemical properties of the drug in question as well as the anatomy and physiology of the organism. Unlike with molecular drugs, nanoparticle parameters often need to be estimated by fitting models to time-course data, which can result in large uncertainties in parameter estimates due to a high-dimensional parameter space. Our research addresses this challenge by offering a path to parameter insights using global sensitivity analysis. The first chapter is an overview of the PBPK model structure and mathematical framework used in our …

Fabrication And Characterization Of Carbon Nanotube Metal Matrix Composites For Use In Photovoltaic Gridline Applications, Cayla M. Nelson

Nanoscience and Microsystems ETDs

Performance reliability is crucial for photovoltaic (PV) cells in both terrestrial and space-based applications. Electrical efficiency losses over time are heavily impacted by electrical losses due to microcracks within the cell structure and metallization failure. Mechanical stresses and thermal cycling of the device can lead to fracture of the current-carrying metal (Ag) lines on the surface of the device, significantly reducing output power. Incorporating carbon nanotubes (CNTs) into PV metal lines as a reinforcement, forming a CNT/Ag metal matrix composite (MMC), enhances the electrical and mechanical performance of the device. In this work the influence of CNT/Ag MMCs were explored …

Characterization Of Electrophoretic Deposited Zinc Oxide Nanopartices For The Fabrication Of Next-Generation Nanoscale Electronic Applications, Fawwaz Abduh A. Hazzazi

LSU Doctoral Dissertations

Several reports state that it is crucial to analyze nanoscale semiconductor materials and devices with potential benefits to meet the need for next-generation nanoelectronics, bio, and nanosensors. The progress in the electronics field is as significant now, with modern technology constantly evolving and a greater focus on more efficient robust optoelectronic applications. This dissertation focuses on the study and examination of the practicality of Electrophoretic Deposition (EPD) of zinc oxide (ZnO) nanoparticles (NPs) for use in semiconductor applications.

The feasibility of several synthesized electrolytes, with and without surfactants and APTES surface functionalization, is discussed. The primary objective of this study …

Passive Radiative Cooling By Spectrally Selective Nanoparticles In Thick Film Nanocomposites, David Allen Young

USF Tampa Graduate Theses and Dissertations

Passive cooling of buildings is a benefit to society since no energy input is required for space cooling which reduces electricity consumption, fossil fuel burning, and greenhouse gas emissions. When a passive cooling technology radiates heat from the earth through the atmospheric windows to space higher levels of cooling power are possible -- this phenomenon is classified as passive “radiative” cooling. Spectrally selective surface coatings provide radiative cooling to lower surface temperatures by reflecting most solar radiation, while emitting infrared radiation at wavelengths between 8-13 μm through the primary atmospheric window to the cold of space. Multiple applications of radiative …

Biomimetic Strategies To Control Therapeutic Release From Novel Dna Nanoparticles, Robert J. Mosley

Theses and Dissertations

The inherent chemical, mechanical, and structural properties of nucleic acids make them ideal candidates for the formulation of tunable, personalized drug nanocarriers. However, none so far have exploited these properties for the controlled release of therapeutic drugs. In this dissertation, a biomimetic approach to controlling drug release is exhibited by specifically manipulating the architecture of novel, DNA nanoparticles to take advantage of drug binding mechanisms of action. Rationally designed DNA strands were immobilized on gold surfaces via a terminal thiol modification. Immobilized monomers can be manipulated to form distinct monolayer architectures including flat, folded, coiled, or stretched structures. Increasing the …

Carbon Nanotube-Based Microscale Capacitive Flow Sensors, Nathaniel Holmes

Electronic Thesis and Dissertation Repository

Micro-scale flow sensors present several advantages over traditional flow sensing
methods, including minimal flow disruption, high spatial resolution, and low unit
cost. Many existing micro-scale thermal and piezo flow sensors struggle with temperature drift and require complicated fabrication processes. This thesis details
the development of a 60 μm by 60 μm by 50 μm drag-based capacitive flow sensor
constructed from vertically aligned carbon nanotube forests. The construction
of a thermal chemical vapour deposition system for sensor synthesis is also de-
tailed. Manual manipulation of the sensor with an atomic force microscope probe
was found to produce a full scale signal …

Uv Space Imager Enclosure Coating, David Silva Cortez, Victor Alexander Rempel Dekhtyar, Maria L. Muñoz

Mechanical Engineering

The goal of this project is to reduce the amount of stray light entering an ultraviolet (UV) imager through absorption. This report outlines the use of ZnO nanoparticles mixed in an epoxy matrix for use in a CubeSat enclosure. Through testing, our team verified that the ZnO and epoxy coating experienced a peak absorption between 360-370 nm. The epoxy mixture with the .75% by weight ZnO nanoparticles absorbed up to 99.9 % of UV light at its peak. The effect on material properties, such as Young’s modulus and ultimate tensile strength, was also tested. Tensile tests demonstrated that adding ZnO …

A Python Implementation Of The Quasi-Harmonic Approximation: Ab-Initio Study Of The Thermoelastic Properties Of Magnesium Oxide And Calcium Oxide, Adewumi Bakare

Dissertations, Theses, and Capstone Projects

When heated up, materials change volume, typically they expand, and they also change their elastic properties, typically by softening. Computational methods to calculate materials properties at finite temperature are needed to compensate for the lack of experimental data, as well as to predict materials properties at conditions difficult to be reached in experimental labs. In this research project, I designed a set of Python codes implementing a quasi-harmonic approximation (QHA) method to calculate thermodynamic functions at constant volume, equation of state, and the isothermal Bulk modulus of cubic materials. To validate the new computational tools, this implementation of QHA has …

Observation And Control Of Photoemission And Electric Field Enhancement Of Plasmonic Antennas Through Photoemission Electron Microscopy, Christopher M. Scheffler

Dissertations and Theses

Photoemission electron microscopy (PEEM) is an imaging method which uses electrons excited through the photoelectric effect to characterize a sample surface with nanometer-level resolution. In PEEM, a high intensity laser excites electrons from the surface of the material and electron optics are used to form an image from the intensity and spatial distribution of the photoemission from the sample. The goal of this research was to study and maximize light confinement, which was accomplished using plasmonic nanostructures. Surface plasmons represent oscillations in the electron density of a material and can occur along the transition interface between a metal and a …

Thermal Management Using Liquid-Vapor Phase Change In Nanochannels, Sajag Poudel

Dissertations - ALL

Superior wettability of porous medium marks their potential to be used in the field of thermal management employing phase-change heat transfer. Comprehending the phenomena of wicking and liquid-vapor phase-change in micro/nano structured surfaces are key aspects towards advancing heat transfer solutions. In this work, fundamental understanding of droplet wicking, thin-film evaporation, and their subsequent application of heat-flux removal for cooling technology is first reported. The latter part of the dissertation is related to the disjoining pressure driven flow of nanoscale liquid film and liquid-vapor phase change in nano confinement. First, experimental and numerical investigation of droplet wicking in ∼728 nm …

Application Of Bismuth Oxychloride As A Colorimetric Uv Sensor Material, Kyle James Troche

Nanoscience and Microsystems ETDs

Sunlight contains about 9% UV radiation with roughly one-third of it penetrating the atmosphere and reaching the Earth’s surface. UV radiation from the sun is classified into three different types: UVA (315- 499 nm), UVB (280- 314nm), and UVC (100- 279 nm). Prolonged exposure to artificial UV radiation or direct sunlight can still induce many adverse effects such as sunburn, weakening of the immune system, and skin cancer. A wide variety of photoresistor, photodiode and colorimetric UV sensors are currently being researched to help monitor UV radiation. Our research is focused on developing a colorimetric UV sensor that is inherently …

Resistive Pulse Sensing Of Protein Unfolding And Transport In Solid-State Nanopores, Jugal Saharia

Mechanical Engineering Research Theses and Dissertations

Solid-state nanopore sensors have attracted considerable attraction as a tool for solution-based single-molecule studies and have been successfully utilized for characterization of biomolecules such as nucleic acids, proteins, glycans, viruses, etc. Among these, characterization of proteins has been more challenging due to their charge heterogeneity and the complex energy landscape associated with different protein conformations. Presented in this thesis is the fabrication of solid-state nanopores and their application for characterizing proteins and understanding their transport through nanopores. Fabrication of nanometer-sized pores in Si_xN_y membranes was achieved using the conventional controlled dielectric breakdown method as well as a …

Surface Acoustic Wave Characterization And Interdigitated Transducer Optimization For Studying Stress-Enhanced Phenomena, Brian D. Rummel

Nanoscience and Microsystems ETDs

Surface acoustic wave devices have not yet achieved their full potential as the effects of standing acoustic fields on stress-sensitive phenomena in semiconductor systems have been largely unexplored. From this perspective, it is necessary to develop novel methods to characterize surface acoustic wave devices quantitatively and prepare an experimental platform to probe stress-enhanced processes. In this dissertation, interdigitated transducer devices are fabricated on gallium arsenide to evaluate their potential impact on strain-enhanced phenomena. A novel Raman characterization technique characterizes the surface stress induced by a standing acoustic field, revealing stress values on the order of 10⁸ Pa. FEM software …

Enhancing Optical And Thermal Properties Of Nanofibrous Films Inspired By The White Beetle Scale, Bokyung Park

Nanoscience and Microsystems ETDs

The Cyphochilus white beetle has received significant attention recently for its exceptional visible-light-scattering properties, owing to the beetle scale's anisotropic nano-fibrillar network structure. Inspiration from the remarkable optical properties of these biological species has directed research efforts to fabricating biomimetic nano-fibrillar structures with polymer materials. In this work, electrospun silk fibroin polymer films reproduce the white beetle scale's anisotropic nature to draw on its optical scattering properties and further improve the radiative-cooling capabilities of silk fabrics. An anisotropically restructured silk film with a mean fiber diameter of a few hundred nanometers substantially increases optical scattering strength in the visible spectrum …

Photocatalytic Degradation Of Organic Contaminants By Titania Particles Produced By Flame Spray Pyrolysis, Noah Babik

Theses and Dissertations

Advanced oxidation of organic pollutants with TiO2 photocatalysts is limited due to the wide bandgap of TiO2, 3.2 eV, which requires ultraviolet (UV) radiation. When nanosized TiO2 is modified by carbon doping, charge recombination is inhibited and the bandgap is narrowed, allowing for efficient photodegradation under visible light. Here, we propose a flame spray pyrolysis (FSP) technique to create TiO2. The facile process of FSP has been successful in preparing highly crystalline TiO2 nanoparticles. Using the same procedure to deposit TiO2 onto biochar, the photocatalyst was doped by the carbonaceous material. The morphology, crystalline and electronic structure of the FSP …

Cmos Compatible Carbonization Of Polymer For Elctrochemical Sensors, Mohammad Aminul Haque

Doctoral Dissertations

Carbon-based electrodes that are integrable with CMOS readout electrodes possess great potential in a wide range of cutting-edge applications. The primary scientific contribution is the development of a processing sequence which can be implemented on CMOS chips to fabricate pyrolyzed carbon microelectrodes from 3D printed polymer microstructures to develop lab-on-CMOS monolithic electrochemical sensor systems. Specifically, optimized processing conditions to convert 3D printed polymer micro- and nano-structures to carbonized electrodes have been explored in order to obtain sensing electrodes for lab-on- CMOS electrochemical systems. Processing conditions have been identified, including a sequel of oxidative and inert atmosphere anneals to form pyrolyzed …

Towards Environmental Sustainability Of Nanotechnology Through Improved Evaluations Of Impact And Risk To Aquatic Species: Cross-Species Comparisons From The Laboratory And Environmentally Realistic Exposure Scenarios In The Field, Becky J. Curtis

Theses and Dissertations

Engineered nanomaterials (ENMs) are utilized in a wide variety of applications and products, including everything from toothpaste and personal care products to industries such as aerospace, defense, medicine, electronics, and agriculture. Depending on the application, release of ENMs to the environment may occur through both unintentional and deliberate routes. High surface-area-to-volume ratios make ENMs more volatile than bulk counterparts, and their small size allows translocation within biological systems that would not be possible with larger materials. These and other characteristics make ENM-biological system interactions unpredictable, creating uncertainty about their potential risks to environmental health. The purpose of this research is …

Synthesis Of Monodisperse Nanoscintillators At High Temperatures For Biomedical Relevant Applications, Eric Zhang

All Dissertations

Luminescent sub-100 nm particulates continuously generate immense research interest in the biomedical field for imaging, theranostics, and optogenetics. Conventionally, upconversion nanoparticles or UV activated semiconductors are studied, however these materials are limited by biological barriers such as the skin which reduces the penetration depth of these excitation sources, tissue's auto- fluorescence, and toxicity. One approach to overcome these challenges is to use nanoscintillators (sub-100 nm materials that can generate visible light using high energy excitation sources such as x-rays) which can generate light locally to the human body. Numerous scintillators have been reported since the discovery of x-rays from the …

Rational Design Of Composite Nanomaterials For Water Treatment Applications, Mariana Marcos-Hernandez

Open Access Theses & Dissertations

Water quantity and quality have been affected in communities all around the world due to population growth, pollution, changes in land use, and climate change. In order to cope with existing and anticipated water demands and shortages, the use of treated or reclaimed water is an ongoing alternative that has helped communities all over the world address this problem. The adaptation of nanotechnology to traditional water and wastewater treatment processes offers new opportunities in technological developments. Unique size-dependent properties such as: high surface to mass ratio, high reactivity, high sorption capacities, fast dissolution, superparamagnetism, among others, provide high-tech efficient materials …

Study Of The Chemical Fabrication Process Of Nsom Probes And The Modification Of The Probe Surface, Muhammad Nazmul Hussain

Theses and Dissertations

Near-field scanning optical microscopy (NSOM) merges scanning probe technology with the power of high-resolution optical microscopy and provides a natural view into the nanoworld. NSOM requires tapered probes with subwavelength optical apertures and wide cone angles to efficiently channel the illumination light to the tip apex so that it can acquire optical images beyond the diffraction limit. Tapered probes with a range of cone angles can be fabricated through chemical etching of optical fibers using hydrofluoric acid (HF) by varying the etching time. Apart from their use for NSOM imaging, such optical probes can also be transformed into nanosensors by …

Towards Highly Sensitive Capacitance Measurements Of A Quantum Anomalous Hall Phase In Van Der Waal Heterostructures, Kayla Cerminara

UNLV Theses, Dissertations, Professional Papers, and Capstones

One of the pioneering achievements in condensed matter physics of the 20th century is the observation of the quantum Hall e↵ect (QHE) in which the Hall resistance in a two-dimensional (2D) sample takes on quantized values in the presence of a strong perpendicular magnetic field. The precise quantization of the hall resistance to one part in a billion has provided a practical, worldwide resistance standard. A long-standing goal has been to realize a similar state of matter but without the need of a strong quantizing magnetic field. The quantum anomalous Hall e↵ect (QAHE) is such a state that is predicted …

Photoassisted Nanoscale Memory Resistors, Amir Shariffar

Graduate Theses and Dissertations

Memristors or memory resistors are promising two-terminal devices, which have the potential to revolutionize current electronic memory technologies. Memristors have been extensively investigated and reported to be practical devices, although they still suffer from poor stability, low retention time, and laborious fabrication processes.

The primary aim of this project was to achieve a device structure of quantum dots or thin films to address a fundamental challenge of unstable resistive switching behavior in memristors. Moreover, we aimed to investigate the effects of light illumination in terms of intensity and wavelength on the performance of the fabricated memristor. The parameters such as …

Nanoparticles For Biomedical Applications, Joseph Kim

Dissertations & Theses (Open Access)

This thesis presents development and evaluation of the potential of three new nanoparticles for biomedical applications. With the rapid growth of the field of nanoscience, researchers have explored developing nanoparticles for various biomedical applications, including imaging, therapy, and drug delivery. This thesis demonstrates the development of two C­₆₀ fullerene based nanoparticles and one boron based nanoparticle to answer key questions related to their biological potential.

In the first part of the thesis, we describe synthesis and characterization of a pure boron nanoparticle containing asolectin phospholipid-based liposome construct prepared using a water-in-oil emulsion method, as a novel alternative agent for …

Structural Evolution During Synthesis And Annealing Of Platinum-Nickel Bimetallic Nanoparticles, Xiner Lu

All Theses

In the past years, there has been an increasing interest in synthesizing Pt alloy nanocrystals to achieve high catalytic performance for energy-related applications. Pt-Ni nanoparticles (NPs) have shown high electrocatalytic activity for electrocatalysis and thermal catalysis. However, the stability of surface structures and compositions still needs to be improved to obtain better long-term catalytic stability. It is noted that thermal annealing can adjust the surface structures and compositions to improve the stability. Transmission electron microscopy (TEM) plays a vital role in characterizing the morphology, structure, and composition of nanoparticles. Specifically, the utilization of in situ TEM can allow for observing …

A Versatile Python Package For Simulating Dna Nanostructures With Oxdna, Kira Threlfall

Computer Science and Computer Engineering Undergraduate Honors Theses

The ability to synthesize custom DNA molecules has led to the feasibility of DNA nanotechnology. Synthesis is time-consuming and expensive, so simulations of proposed DNA designs are necessary. Open-source simulators, such as oxDNA, are available but often difficult to configure and interface with. Packages such as oxdna-tile-binding pro- vide an interface for oxDNA which allows for the ability to create scripts that automate the configuration process. This project works to improve the scripts in oxdna-tile-binding to improve integration with job scheduling systems commonly used in high-performance computing environments, improve ease-of-use and consistency within the scripts compos- ing oxdna-tile-binding, and move …

A Performance Guide For Four Songs By Francisco Mignone, Amanda Mara Rizzotto Vidal Pessoa

UNLV Theses, Dissertations, Professional Papers, and Capstones

The scope of this document is to demonstrate the richness and diversity to be found in the art song genre from countries outside of the standard repertoire, specifically focusing on the Brazilian composer Francisco Mignone. The purpose of this document is to provide performance practice guidelines for four selected pieces by Francisco Mignone: No Meio do Caminho (1938), Pregão (1947), Si eu sei o que é saudade (1976), and Valsa-Vocalise (1972). They exemplify expressions of Brazilian national identity through the music selected. Furthermore, it provides a brief background on the composer and his compositional style phases, and context for the …

Surface-Functionalized Chemiresistive Films That Exploit H-Bonding, Cation-Pi, And Metal-Halide Interactions., Prasadanie Karunarathna Adhihetty

Electronic Theses and Dissertations

The development of gas sensors for detection of volatile organic compounds (VOCs) has been of interest in the sensing field for decades. To date, the use of metal nanoparticle-based chemiresistors for trace VOC detection, particularly gold nanoparticle-based sensors, is of great interest due to their high chemical stability, ease of synthesis, unique optical properties, large surface to volume ratio, and high level of conductivity. Much effort has been devoted towards gold monolayer protected clusters (Au MPCs) as chemiresistors to detect harmful VOCs. The present thesis documents the results of our efforts to exploit the advantages of functionalized Au MPCs chemiresistors …