Nanoscience and Nanotechnology Commons^™

Fabrication Of Two-Dimensional Material-Based Nano-Capacitors Using Bismuth Selenite (Bi2seo5) To Study Its Dielectric Properties, Major Kc

McKelvey School of Engineering Theses & Dissertations

In recent years, the demand for high-performance micro and nanodevices has surged, necessitating the exploration of novel dielectric materials to replace conventional silicon dioxide. Following the continuation of the Moorse law, as device dimensions reduce to nanoscale levels, the properties of silicon dioxide can degrade, leading to issues such as increased leakage current and reduced gate control. Materials with superior electrical properties, such as higher dielectric constant, lower leakage current, and better thermal stability allowing for the development of faster, more efficient, and more reliable devices are in higher demand than ever. Two-dimensional layered semiconductor nanomaterials represented by compounds such …

Analytical And Experimental Investigation Of Interphase And Dispersion Effects On The Mechanical Stiffness Of Cellulose Nanocomposites, Will Goldberg

McKelvey School of Engineering Theses & Dissertations

The effect of dispersion and interphase properties on the elastic behavior of cellulose nanocomposites was investigated using a number of composite models, experimental data and a thorough literature review. Cellulose nanocomposites consisting of soy protein isolate (SPI) and cellulose nanocrystals (CNC) or polydopamine coated cellulose nanocrystals (PD-CNC) were prepared via solution casting method and tested for mechanical stiffness. These outcomes were compared to standard composite models as well as novel methods adapted from the literature that incorporate data regarding dispersion quality and interphase properties. The literature review verified that both dispersion and interphase properties are highly dependent on interfacial chemistry …

Synthesis And Consolidation Of Metal Oxide Nanocrystals Via Nonthermal Plasma, Austin Cendejas

McKelvey School of Engineering Theses & Dissertations

Nonthermal plasmas offer a unique nonequilibrium environment that has been leveraged in a wide variety of applications in the fields of material processing, lighting, and waste management to name a few. In all of these cases, the plasma serves as a source of high energy electrons, ions, reactive gas species, and radicals that interact in several ways with surfaces brought into contact with the plasma. Specifically, nonthermal plasmas have been shown to be very successful in achieving continuous, high-throughput, monodisperse nanocrystals of a wide variety of materials. The crystallinity of nanoparticles synthesized in nonthermal plasmas can be attributed to the …

Multifunctional Polydopamine Nanomaterials For Biomedical And Environmental Applications, Hamed Gholami Derami

McKelvey School of Engineering Theses & Dissertations

Polydopamine (PDA), a synthetic and organic material, has emerged as a promising materialplatform for various applications in energy, environmental, and biomedical fields. PDA, formed by self-polymerization of dopamine, is rich in catechol and amine groups, which facilitate covalent conjugation and/or other non-covalent interactions with organic and inorganic materials. It is highly biocompatible, biodegradable, has broadband light absorption spectrum and excellent light-to-heat conversion efficiency. Also, it is easy to synthesize and functionalize. The combination of excellent characteristics of polydopamine-based nanomaterials, make them a promising adsorbent agent for environmental wastewater treatment and photothermal agent for biomedical applications. In the first half of …

Growth Of Small Particles In Nonequilibrium Plasmas, Necip Berker Üner

McKelvey School of Engineering Theses & Dissertations

Nonequilibrium plasma (NEP) is an extraordinary environment for material synthesis. NEP is comprised of hot electrons with temperatures greater than 10000 K and of cold ions and neutrals that are usually at few hundred kelvins above room temperature. Due to this large difference in species’ temperatures, the assumption of local thermal equilibrium does not hold in NEP. Therefore, NEP can act as a unique processor of mass, and it can transform materials along pathways that are not accessible by methods wherein local thermal equilibrium is valid. For decades, NEPs have been employed in the semiconductor industry to manufacture many thin …

Defect Chemistry And Ion Intercalation During The Growth And Solid-State Transformation Of Metal Halide Nanocrystals, Bo Yin

McKelvey School of Engineering Theses & Dissertations

Abstract of the Dissertation

Defect Chemistry and Ion Intercalation During the Growth and Solid-State Transformation of Metal Halide Nanocrystals

Semiconductor metal halides as light-sensitive materials have applications in multiple areas, such as photographic film, antibacterial agents and photocatalysts. One focus of this dissertation is to achieve novel morphologies of ternary silver bromoiodide (AgBr1-xIx, 0

For the silver halide system, we demonstrate that the anion composition of AgBr1-xIx nanocrystals determines their shape through the introduction of twin defects as the nanocrystals are made more iodide-rich. AgBr1-xIx nanocrystals grow as single-phase, solid solutions with the rock salt crystal structure for anions compositions …

Towards Engineering Advanced Nanomaterials: Elucidating Fundamental Particle Behavior In Water And Critical Sorption Dynamics, Changwoo Kim

McKelvey School of Engineering Theses & Dissertations

As advanced nanomaterials, inorganic-organic nano composites have received great interest as potential platform (nano) structures for sensor, catalyst, sorbent, and environmental applications. Here, my Ph.D. research has focused on the design, synthesis, and characterization of advanced water-stable engineered metal-oxide nanoparticles functionalized by organic frames for environmental applications. For the environmental applications, I have evaluated particleoptimized sorption processes for the remediation and separation of arsenic, chromium, and uranium under environmentally relevant conditions. More specifically, I have explored the critical role of organic coating on sorption mechanisms and performances using engineered iron oxide -based, manganese oxide -based, and manganese ferrite -based (core) …

Development And Evaluation Of Biocompatible Engineered Nanoparticles For Use In Ophthalmology, Bedia Begum Karakocak

McKelvey School of Engineering Theses & Dissertations

The synthesis and design of biocompatible nanoparticles for targeted drug delivery and bioimaging requires knowledge of both their potential toxicity and their transport. For both practical and ethical reasons, evaluating exposure via cell studies is a logical precursor to in vivo tests. As a step towards clinical trials, this work extensively investigated the toxicity of gold nanoparticles (Au NPs) and carbon dot (CD) nanoparticles as a prelude to their in vivo application, focusing specifically on ocular cells. As a further step, it also evaluated their whole-body transport in mice. The research pursued two approaches in assessing the toxicity of engineered …

Increasing Ph In Cancer: Enabling A New Therapeutic Paradigm Using Novel Carbonate Nanoparticles, Avik Som

McKelvey School of Engineering Theses & Dissertations

Enormous progress has been made to treat cancer, and yet the mortality rate of cancer remains unacceptably high. High clinical resistance to molecularly targeted therapeutics has pushed interest again towards inhibiting universal biochemical hallmarks of cancer. Recent evidence suggests that malignant tumors acidify the local extracellular environment to activate proteases for degrading the tumor matrix, which facilitates metastasis, and explains why more aggressive tumors are more acidic. Current therapies have only focused on using the low pH for enhancing drug release in tumors, thereby still relying on the traditional paradigm of intracellular inhibition of pathways, a method that continues to …

Functional Bio-Nano Hybrids Through A Precise Control Of Interfacial Interactions At The Nanoscale, Sirimuvva Tadepalli

McKelvey School of Engineering Theses & Dissertations

During the course of evolution, proteins have evolved to perform exquisite functions including structural support, signal transduction, actuation, sensing, catalysis, trafficking, gating, light-harvesting, charge transfer, molecular recognition, self-assembly, self-organization, or combinations of two or more of these functions. A precise control and manipulation of the structure and function of proteins is conceivable with the advent of nanotechnology, which has facilitated the integration of nanomaterials with functional biomolecules to realize bio-nano hybrids with synergistically enhanced functionalities.

At the genesis of bionanotechnology, a paucity in the fundamental understanding of the bio-nano interfaces is a grave impediment to the progress of the field. …

Activity Preservation Of Plasmonic Biosensors With A Metal-Organic Framework, Lu Wang

McKelvey School of Engineering Theses & Dissertations

Antibody-antigen recognition enables antibody-conjugated nanostructures to serve as plasmonic biosensors with tunable specificity. However due to the instability of antibodies, these biosensors are susceptible to changes in the environment such as heat and aridity, leading to constraints on the transportation and handling of these sensors. Here we establish a method using a metal-organic framework crystal to preserve biosensor activity under severe environmental conditions, including exposure to high temperatures, an organic solvent and a proteolytic agent. After zeolitic imidazolate framework-8 (ZIF-8) crystals formed for 12 hours on a biosensor of gold nanorods conjugated with a model antibody, rabbit IgG, 80% of …

Development And Evaluation Of A Near-Infrared (1047 Nm) Photoacoustic-Nephelometer Spectrometer For Detection And Optical Characterization Of Black Carbon Aerosol, Yang Yu

McKelvey School of Engineering Theses & Dissertations

Black carbon (BC) aerosol are aggregates of small carbon spherules of <10 nm to approximately 50 nm in diameter. They are characterized by their strong visible light absorption property with a mass absorption cross-section (MAC) value above 5 m² g ⁻¹ at a wavelength λ = 550 nm, which increases inversely with wavelengths from near-infrared (≈1 µm) to ultraviolet with a power law of one. The absorbing nature of BC aerosol has been implicated in regional atmospheric warming, changing of monsoon patterns, and accelerated melting of the glaciers. The BC radiative effects over earth is currently estimated within a factor of four, resulting in one of the largest uncertainties in climate modeling. This uncertainty results from our inadequate knowledge about regional BC emission rates, and associated aerosol …

Contact Radius And Insulator-Metal Transition In Films Comprised Of Touching Semiconductor Nanocrystals, Deanna M. Lanigan

McKelvey School of Engineering Theses & Dissertations

Nanocrystal assemblies are being explored for a number of optoelectronic applications such as transparent conductors, photovoltaic solar cells, and electrochromic windows. Majority carrier transport is important for these applications, yet it remains relatively poorly understood in films comprised of touching nanocrystals. Specifically, the underlying structural parameters expected to determine the transport mechanism have not been fully elucidated. In this report, we demonstrate experimentally that the contact radius, between touching heavily doped ZnO nanocrystals, controls the electron transport mechanism. Spherical nanocrystals are considered, which are connected by a circular area. The radius of this circular area is the contact radius. For …

Feed-Forward Inhibitory Circuits In Hippocampus And Their Computational Role In Fragile X Syndrome, Sarah Lauren Wahlstrom Helgren

McKelvey School of Engineering Theses & Dissertations

Feed-forward inhibitory (FFI) circuits are canonical neural microcircuits. They are unique in that they are comprised of excitation rapidly followed by a time-locked inhibition. This sequence provides for a powerful computational tool, but also a challenge in the analysis and study of these circuits. In this work, mechanisms and computations of two hippocampal FFI circuits have been examined. Specifically, the modulation of synaptic strength of the excitation and the inhibition is studied during constant-frequency and naturalistic stimulus patterns to reveal how FFI circuit properties and operations are dynamically modulated during ongoing activity. In the first part, the FFI circuit dysfunction …

Entry Flow And Heat Transfer Of Laminar And Turbulent Forced Convection Of Nanofluids In A Pipe And A Channel, Yihe Huang

McKelvey School of Engineering Theses & Dissertations

This thesis presents a numerical investigation of laminar and turbulent fluid flow and convective heat transfer of nanofluids in the entrance and fully developed regions of flow in a channel and a pipe. In recent years, nanofluids have attracted attention as promising heat transfer fluids in many industrial processes due to their high thermal conductivity. Nanofluids consist of a suspension of nanometer-sized particles of higher thermal conductivity in a liquid such as water. The thermal conductivity of nanoparticles is typically an order-of-magnitude higher than the base liquid, which results in a significant increase in the thermal performance of the nanofluid …

Optical Resonators And Fiber Tapers As Transducers For Detection Of Nanoparticles And Bio-Molecules, Huzeyfe Yilmaz

McKelvey School of Engineering Theses & Dissertations

In recent years, detection of biological interactions on single molecule level has aspired many researchers to investigate several optical, chemical, electrical and mechanical sensing tools. Among these tools, toroidal optical resonators lead the way in detection of the smallest particle/molecule with the real time measurements. In this work, bio-sensing capabilities of toroidal optical resonators are investigated. Bio-sensing is realized via measuring the analyte-antigen interaction while the antigen is immobilized through a novel functionalization method.

Not long ago, detection of single nanoparticles using optical resonators has been accomplished however the need for cost-effective and practical transducers demands simpler tools. A tapered …