Materials Science and Engineering Commons^™

Structure-Property-Processing Analysis Of Graphene Bioscaffolds For Viability And Differentiation Of C2c12 Cells, Lynn Karriem

Boise State University Theses and Dissertations

We investigated the structure – property – processing correlation of graphene bioscaffolds produced using three different methods. Bioscaffolds were prepared by chemical vapor deposition (CVD), sublimation of Silicon Carbide (SiC), and printed solvent assisted exfoliated graphene ink. To gain insight into the roughness and topography of graphene, AFM was performed on each bioscaffold. Raman spectroscopy mapping demonstrated differences in the I_2D/I_G ratio for each scaffold. Young’s modulus was determined by nanoindentation and indicated that epitaxial graphene had the highest average stiffness, followed by CVD, with printed graphene demonstrating the lowest average stiffness. To investigate the biocompatibility of …

Heteroepitaxy Of Gasb On Gaas (111)A For Electron Transport Studies, Madison Drake

Boise State University Theses and Dissertations

III-V semiconductors grown by molecular beam epitaxy (MBE) on (111) surfaces have some interesting electronic properties. For certain materials with a (111)-orientation, the Γ- and L-valleys are reasonably close in energy. This means that it may be possible to take advantage of electron conduction in the L- and Γ-valleys at the same time, allowing us to overcome the so-called “density-of-states bottleneck,” and enable transistors with large drive currents.¹ We have investigated this phenomenon in GaSb- and InAs-based 2D electron gases for which the electron effective masses are low.

However, growth of materials with a (111) orientation is typically more …

Deep Learning Of Microstructures, Amir Abbas Kazemzadeh Farizhandi

Boise State University Theses and Dissertations

The internal structure of materials also called the microstructure plays a critical role in the properties and performance of materials. The chemical element composition is one of the most critical factors in changing the structure of materials. However, the chemical composition alone is not the determining factor, and a change in the production process can also significantly alter the materials' structure. Therefore, many efforts have been made to discover and improve production methods to optimize the functional properties of materials. The most critical challenge in finding materials with enhanced properties is to understand and define the salient features of the …

Open-Source Workflows For Reproducible Molecular Simulation, Jenny W. Fothergill

Boise State University Theses and Dissertations

We apply molecular simulation to predict the equilibrium structure of organic molecular aggregates and how these structures determine material properties, with a focus on software engineering practices for ensuring correctness. Because simulations are implemented in software, there is potential for authentic scientific reproducibility in such work: An entire experimental apparatus (codebase) can be given to another investigator who should be able to use the same processes to find the same answers. Yet in practice, there are many barriers which stand in the way of reproducible molecular simulations that we address through automation, generalization, and software packaging. Collaboration on and application …

Reproducible Prediction Of Organic Semiconductor Properties Through Open Source Software Development, James Rushing

Boise State University Theses and Dissertations

Semiconducting materials made from carbon-based molecules are potential replacements for inorganic semiconductors, but with lower costs of processing. Devices made from organic semiconductors can be produced at scale by inkjet printing and roll-to-roll manufacturing of these molecules in solution or melt phases. The efficiency of these organic devices is dependent on the structure of the active layer, so controlling the morphology of organic molecules through self-assembly during manufacturing is a key challenge to realizing their utility. Molecular self-assembly depends on the chemical structure of the molecules, how key moieties interact with each other and with any solvent present, and the …

Study As Form-Of-Life: Meditations On Schooling, Enjoyment, And The Inoperative Life, Bryan K. Weeks

Boise State University Theses and Dissertations

The aim of this thesis is to explore what potential that the concept of 'inoperativity' has in the philosophy and theory of education. I will discuss the method of critique used which aims to think through the problems in existing theory rather than discard good thinking when problems are found. The strengths and weaknesses of deschooling and democratic approaches will be at the center of this critique. As a response to the weaknesses of both, the philosophy of Emmanuel Levinas, focusing on the way that interiority and enjoyment are essential concepts for the philosophy of education, as well as Giorgio …

Additive Manufacturing Of Sensors For Extreme Environments, Kiyo Tiffany Fujimoto

Boise State University Theses and Dissertations

Advanced manufacturing based direct-write technologies have emerged as the predominant enabler for the fabrication of active and passive sensors for use in harsh operating environments. The ability to directly write and integrate electronic components onto physical packaging can be achieved with additive manufacturing (AM) methods such as direct write technologies (DWT) which include aerosol jet printing (AJP), Ink Jet Printing (IJP), Plasma Jet Printing (PJP), and Micro-Dispense Printing (MDP). In this work, we investigate the use of these methods to accelerate, modernize, and enhance the functionality of sensors and instrumentation to achieve the goal of improving the safety and efficiency …

Electrochemical Impedance Spectroscopy Of Zirconium Oxidation For In-Situ Nuclear Sensing Applications, Michael Andrew Reynolds

Boise State University Theses and Dissertations

To meet the ever-growing energy demands of the modern world, alternative forms of producing power are necessary, and the field of nuclear engineering holds promise to answer this call. Nuclear fuel cladding in light water reactors (LWRs) currently draws a large amount of attention from scientists and researchers, as it provides many challenges to design around. Since the 1950s, zirconium and its protective oxide layer have been utilized as an effective material for the task, possessing good mechanical strengths, high corrosion resistance, and a low neutron absorption cross section. Despite these beneficial properties, however, fuel cladding remains vulnerable to several …

Towards Improving The Properties And Furthering Acceptance Of Advanced Technology Nuclear Fuels, Jennifer K. Watkins

Boise State University Theses and Dissertations

To avoid detrimental environmental impacts from climate change, the world community needs to push for the use of clean energy technologies. Development of proposed advanced technology nuclear fuels supports efforts to ensure nuclear energy is included as a non-carbon emitting source of electricity generation. Advanced technology nuclear fuels, also referred to as accident tolerant fuels (ATFs), have received renewed interest for use in the current nuclear reactor fleet as well as in advanced reactor technologies due to their high uranium loading, desirable thermophysical properties, and performance under irradiation as compared to the benchmark oxide fuel. A limiting consideration for the …

Dreams Of Molecular Beams: Indium Gallium Arsenide Tensile-Strained Quantum Dots And Advances Towards Dynamic Quantum Dots (Moleculare Radiorum Somnia: Indii Gallii Arsenicus Tensa Quanta Puncta Et Ad Dinamicae Quantae Puntae Progressus), Kevin Daniel Vallejo

Boise State University Theses and Dissertations

Through the operation of a molecular beam epitaxy (MBE) machine, I worked on developing the homoepitaxy of high quality InAs with a (111)A crystallographic orientation. By tuning substrate temperature, we obtained a transition from a 2D island growth mode to step- ow growth. Optimized MBE parameters (substrate temperature = 500 °C, growth rate = 0.12 ML/s and V/III ratio ⩾ 40) lead to growth of extremely smooth InAs(111)A films, free from hillocks and other 3D surface imperfections. We see a correlation between InAs surface smoothness and optical quality, as measured by photoluminescence spectroscopy. This work establishes InAs(111)A as a platform …

Structure And Kinetics Of Twin Boundaries In Shape Memory Alloys, Bibek Jung Karki

Boise State University Theses and Dissertations

Shape memory alloys (SMAs) are functional materials that recover from large strains without permanent deformation. In magnetic shape memory alloys (MSMAs), the reversible deformation is driven either magnetically or mechanically. Two underlying phenomena are responsible for the shape memory effect: (a) a diffusionless, martensitic transformation and (b) twinning in the martensite phase.

In MSMAs, the reversible plastic deformation occurs via twinning in the martensite phase, particularly via the movement of twinning disconnections (TDs) along the twin boundaries (TBs). A geometric algorithm called the classical model (CM) of deformation twinning describes operative twinning modes of a given crystal system. There are …

How To Recognize And Control Interfacial Phenomena That Hinder The Advancement Of Clean Energy Technologies, Corey Michael Efaw

Boise State University Theses and Dissertations

Nuclear energy and electrochemical energy storage, such as batteries, are key parts to the clean energy transition of critical infrastructure. This work aims to define, monitor, and modify interfacial layers that would improve the utility of materials in harsh environments seen in nuclear and energy storage applications. First, the studying of zirconium alloys, which is used as nuclear cladding, was done to better understand the degradation mechanisms within an extreme environment. High-resolution characterization techniques were used to correlate corrosion mechanisms to equivalent circuit models from novel in-pile electrochemical impedance spectroscopy sensors. Advancement in this sensor technology could provide further insight …

Application Of In Situ And Ex Situ Characterization Of Atomic Layer Deposition Processes For Gallium Phosphide And Sodium Fluoride, Sara Rose Kuraitis

Boise State University Theses and Dissertations

Atomic layer deposition (ALD) is a vapor deposition technique for synthesizing thin films with nanometer thickness control. ALD films are deposited on a substrate surface in a cyclic layer-by-layer fashion utilizing alternating doses of highly reactive chemical precursors. Precursors are selected to undergo self-limiting chemical reactions with the surface, and desired film thickness is achieved by varying the number of ALD cycles accordingly. Optimization of ALD process parameters and precursor chemistry enables conformal coating of arbitrary substrate geometries, including high aspect ratio features such as trenches. In the decades since its introduction, ALD has been used for applications across many …

Computational Modeling Towards Accelerating Accident Tolerant Fuel Concepts And Determining In-Pile Fuel Behavior, Ember Sikorski

Boise State University Theses and Dissertations

To mitigate global warming, we need to develop carbon-free ways to generate power. Nuclear energy currently generates more carbon-free power in the United States than all other sources combined at 55%. To make nuclear as viable a power source as possible, we need to maximize power density and safety. Both of these can be improved with Accident Tolerant Fuel (ATF) materials. Uranium nitride (UN), a candidate ATF material, offers high fuel economy due to its uranium density and improved safety margins from thermal properties. However, its instability in the presence of water, a reactor coolant, must be addressed. This dissertation …

Phase Field Modeling Of Crack Growth In Shape Memory Ceramics, Ehsan Moshkelgosha

Boise State University Theses and Dissertations

Shape memory ceramics (SMCs) are promising candidates for actuators in extreme environments such as high temperature and corrosive applications. Despite outstanding energy dissipation, compared to metallic shape memory materials, SMCs suffer from a sudden brittle fracture. While the interaction of crack propagation and phase transformation in SMCs has been the subject of several experimental and theoretical studies, mainly at the macroscale, the fundamental understanding of the dynamic interaction of crack propagation and martensitic transformation is poorly understood. This dissertation attempts to provide a mathematical model for crack propagation in transformable zirconia to address the shortage of classical methods. This dissertation …

First-Principles Studies Of Nucleation Of Atomic-Layered Molybdenum Disulfide By Atomic Layer Deposition, Matthew Lawson

Boise State University Theses and Dissertations

This dissertation implements first-principles calculations to understand the nucleation mechanisms for atomic layer deposition (ALD) of molybdenum disulfide (MoS₂) using MoF₆ and H₂S precursors. ALD is a self-limiting process that can deposit a range of materials at the nanoscale, while maintaining chemical stoichiometry, atomic scale thickness control, and can conform to high-aspect ratio substrate designs. ALD is extremely sensitive to surface chemistry and morphology; therefore, it is critical to understand how these factors control deposition.

Density functional theory (DFT) was used to understand what factors can control the nucleation for ALD of MoS₂ using …

Tensile-Strained Germanium Quantum Dots Grown On Indium Aluminum Arsenide (111)A And (110) By Molecular Beam Epitaxy, Kathryn Eva Sautter

Boise State University Theses and Dissertations

Molecular beam epitaxy (MBE) enables the growth of semiconductor nanostructures known as tensile-strained quantum dots (TSQDs). The highly tunable nature of TSQD properties means that they are of interest for a wide variety of applications including for infrared (IR) lasers and light-emitting diodes (LEDs), improved tunnel junction efficiency in multijunction solar cell technology, quantum key encryption, and entangled photon emission. In this project, I focus on one of the most technologically important materials, germanium (Ge). Ge has a high gain coefficient, high electron mobility, and low band gap: all excellent properties for optoelectronic applications. Until recently, these technological advantages were …

Defect Evolution In High-Temperature Irradiated Nuclear Graphite, Steve Johns

Boise State University Theses and Dissertations

Graphite has historically been used as a moderator material in nuclear reactor designs dating back to the first man-made nuclear reactor to achieve criticality (Chicago Pile 1) in 1942. Additionally, graphite is a candidate material for use in the future envisioned next-generation nuclear reactors (Gen IV); specifically, the molten-salt-cooled (MSR) and very-high-temperature reactor (VHTR) concepts. Gen IV reactor concepts will introduce material challenges as temperature regimes and reactor lifetimes are anticipated to far exceed those of earlier reactors. Irradiation-induced defect evolution is a fundamental response in nuclear graphite subjected to irradiation. These defects directly influence the many property changes of …

Direct Solar Absorption Nanoparticle Doped Membranes For A Hybrid Membrane Distillation And Photovoltaic Cell, Alejandro Espejo Sanchez

Boise State University Theses and Dissertations

The growing demand for clean water supplies is driving the need for an innovative approach of water desalination. Developing a method for treating water with high salinities is possible with membrane distillation (MD). Additionally, MD is very attractive for pairing with solar energy due to the low temperature requirements. The integration of a membrane distillation system with a photovoltaic (PV) system will result in the co-production of electricity and clean water, thereby improving the economics of MD. Such a hybrid system will directly absorb thermal energy in the membrane for desalination while taking advantage of the spectrally selective nature of …

Additive Manufacturing Of Graphene-Based Devices For Flexible Hybrid Electronics, Twinkle Pandhi

Boise State University Theses and Dissertations

In this work, I investigate and enhance the fundamental sensing properties of printed electronic nanomaterials (e.g., graphene) in real-world environments while decreasing weight, cost, and power consumption. The dissertation addresses this issue with the following foci in mind: (1) developing a straightforward and repeatable process to synthesize graphene ink which is also compatible with Inkjet-printing (IJP) and Aerosol Jet printing (AJP). (2) Tuning additive manufacturing printing (IJP and AJP) parameters to establish a repeatable manufacturing process and print high performing (graphene-based) electrodes and interconnects, compatible with the underlying substrate. (3) Investigate power dissipation and electrical breakdown in AJP printed graphene …

Large Displacement J-Integral Double Cantilever Beam (Dcb) Test Method For Mode I Fracture Toughness, Joshua Gunderson

Boise State University Theses and Dissertations

The J-integral is used to develop an alternative double cantilever beam (DCB) test method for the Mode I fracture toughness suitable for both small and large displacements. The current focus is the experimental determination of the Mode I interlaminar fracture toughness of composite materials, but the method is generally applicable to other similar tests and material systems, such as to the Mode I fracture toughness of adhesives. A series of five identical specimens are tested to compare the linear-elastic fracture mechanics method recommended by ASTM, which makes use of linear beam theory with root rotation, large displacement, and end …

Single Molecule Super-Resolution Microscopy Study On The Precision With Which Dna Nanostructures Can Orient Fluorescent Dyes, Brett Michael Ward

Boise State University Theses and Dissertations

DNA nanotechnology enables the rapid, programmable self-assembly of novel structures and devices at the nanoscale. Utilizing the simplicity of Watson-Crick base pairing, DNA nanostructures are capable of assembling a variety of nanoparticles in arbitrary configurations with relative ease. Several emerging opto-electronic systems require a high degree of control of both the position and orientation of component fluorescent molecules, and while DNA nanostructures have demonstrated these capabilities, the precision with which DNA can orient fluorescent molecules is not well understood. Determining these bounds is critical in establishing the viability of DNA nanotechnology as a method of assembling fluorescent molecular networks.

In …

Mxenes As Flow Electrodes For Capacitive Deionization Of Wastewater, Naqsh E. Mansoor

Boise State University Theses and Dissertations

The energy-water nexus poses an integrated research challenge, while opening up an opportunity space for the development of energy efficient technologies for water remediation. Capacitive Deionization (CDI) is an upcoming reclamation technology that uses a small applied voltage applied across electrodes to electrophoretically remove dissolved ionic impurities from wastewater streams. Similar to a supercapacitor, the ions are stored in the electric double layer of the electrodes. Reversing the polarity of applied voltage enables recovery of the removed ionic impurities, allowing for recycling and reuse. Simultaneous materials recovery and water reclamation makes CDI energy efficient and resource conservative, with potential to …

Material Design, Processing, And Engineering Requirements For Magnetic Shape Memory Devices, Andrew Armstrong

Boise State University Theses and Dissertations

For magnetic shape memory (MSM) alloys, a magnetic field stimulates a shape change. We use the shape change to build devices such as micro-actuators, sensors, and microfluidic pumps. Currently, (as a novel technology,) devices suffer from some material and magnetic driver shortcomings. Here we address the issues related to operating temperature, repeatability, failure, and magnetic driver development. To increase the operating temperature of the MSM material, we alloyed Fe and Cu to Ni-Mn-Ga. We showed that the element-specific contribution to the valence electron density as parameter systematically determines the effect of each element on the variation of the martensite transformation …

Diffusion Bonding Of Inconel 600 To Silicon Carbide For Next Generation High Temperature Applications, Yaiza Rodriguez Ortego

Boise State University Theses and Dissertations

Ceramic to metal interfaces are of interest for applications in extreme environments because they allow increased operational temperatures, resulting in greater thermodynamic efficiency in energy conversion processes. Ceramics offer high temperature corrosion resistance while metals offer robust and versatile solutions to assemblies. Understanding the solid-state reactions, the resulting interfacial microstructure, and the properties of the joints produced by diffusion bonding is essential for developing reliable ceramic to metal interfaces.

The combination of silicon carbide (SiC) and a nickel-based alloy (Inconel 600) offers improved strength and resistance to high temperature degradation. This work focuses on the understanding of the solid-state diffusion …

Empirical Modeling Of Structural Distortions In Perovskite Ceramics, Evan Connor Smith

Boise State University Theses and Dissertations

Predictive models for composition-structure-property relationships are essential to realizing the full potential of electroceramic materials; however, the electroceramics industry has largely failed to invest in predictive models in favor of simple rules of thumb or expensive, time-consuming trial-and-error methods. Empirically derived predictive models have the potential to significantly improve and guide future research in a more cost-effective and timely manner. It may even be possible to predict some intrinsic properties (e.g., polarization) on the order of a unit cell using only the charge and size of each chemical component. Scientists and researchers may ultimately be able to use …

An All-Optical Excitonic Switch Templated On A Dna Scaffold Operated In The Liquid And Solid Phases, Donald L. Kellis

Boise State University Theses and Dissertations

The natural excitonic circuitry of photosynthetic organisms, including light harvesting antennas, provides a distinctive example of a highly attractive bio-inspired alternative to electronic circuits. Excitonics, which capitalizes on spatially arranged optically active molecules ability to capture and transfer light energy below the diffraction limit of light has garnered recognition as a potential disruptive replacement for electronic circuits. However, assembly of optically active molecules to construct even simple excitonic devices has been impeded by the limited maturity of suitable molecular scale assembly technologies.

An example of nanophotonic circuitry, natural light harvesting antennas employ proteins as scaffolds to organize and self-assemble light-active …

Nanoscale Optical And Correlative Microscopies For Quantitative Characterization Of Dna Nanostructures, Christopher Michael Green

Boise State University Theses and Dissertations

Methods to engineer nanomaterials and devices with uniquely tailored properties are highly sought after in fields such as manufacturing, medicine, energy, and the environment. The macromolecule deoxyribonucleic acid (DNA) enables programmable self-assembly of nanostructures with near arbitrary shape and size and with unprecedented precision and accuracy. Additionally, DNA can be chemically modified to attach molecules and nanoparticles, providing a means to organize active materials into devices with unique or enhanced properties. One particularly powerful form of DNA-based self-assembly, DNA origami, provides robust structures with the potential for nanometer-scale resolution of addressable sites. DNA origami are assembled from one large DNA …

Effects Of Magnetic Domain And Twin Boundary Interactions On Magneto-Mechanical Properties Of Magnetic Shape Memory Alloys, Medha Veligatla

Boise State University Theses and Dissertations

Magnetic shape memory (MSM) alloys deform substantially when exposed to a magnetic field. This recoverable plastic deformation occurs through crystallographic twinning. Thereby the internal magnetic domain structure modulates the deformation mechanisms through the interaction of magnetic domains with twin boundaries. We study the meso scale magneto-structural interactions that affect the macroscopic material properties of MSM alloys. The study at the meso length scale is most effective as it allows for resolving interactions at magnetic domain wall width resolution with reasonable computing cost. We apply micromagnetics simulations to evaluate the evolution of magnetic domains, their interaction with twin boundaries, the distribution …

Understanding Self-Assembly And Charge Transport In Organic Solar Cells Through Efficient Computation, Evan Miller

Boise State University Theses and Dissertations

Organic solar cells capable of sustainably generating electricity are possible if: (1) The structures assembled by photoactive molecules can be controlled, and (2) The structures favorable for charge transport can be determined. In this dissertation we conduct computational studies to understand relationships between organic solar cell compounds, processing, structure and charge transport. We advance tools for encapsulating computational workflows so that simulations are more reproducible and transferable. We find that molecular dynamic simulations using simplified models efficiently predict experimental structures. We find that the mobilities of charges through these structures—as determined by kinetic Monte Carlo simulations—match qualitative trends expected with …