Materials Science and Engineering Commons^™

Novel Design And Facile Synthesis Of Functional Nanostructures For Energy And Environmental Application, Zhuojun Wang

Wayne State University Theses

Environmental pollution and energy crisis are two of the major obstacles in the development of a more sustainable society. It is an interesting but technically challenging task to design novel methods for the facile and scalable synthesis of multifunctional materials for applications in both energy storage and environmental remediation. In this thesis, I tried to design and synthesize novel nanostructured materials for energy and environmental applications, achieved highly promising results. I developed a facile electrochemical approach to synthesize the zinc oxide with the zinc element for photocatalytic reactions. It demonstrated dramatically improved performances in degradation of organic pollutant in water, …

Ac Conductivity Studies Of Polyethylene-Oxide-Garnet Type Li7la3zr2o12 Hybrid Composite Solid Polymer Electrolyte For Li-Ion Battery, Parisa Bashiri

Wayne State University Dissertations

Solid electrolytes including ceramics and polymers are considered to be the ultimate substitute for organic liquid electrolytes currently used in commercialized lithium ion batteries to address the safety concerns due to Li dendrite growth and internal short circuiting. However, low ionic conductivity due to high grain boundary resistance in ceramics and semi-crystalline nature of polymers has held back the solid electrolytes from being used in Li-ion batteries. Polyethylene oxide (PEO), complexed with a Li-salt, is a well-studied polymer electrolyte showing ionic conductivity properties at room temperature. However, the coexistence of amorphous and crystalline regions at room temperature (< Tm, the melting temperature) has

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Study Of Grain Growth In Single-Phase Polycrystals, Pawan Vedanti

Wayne State University Dissertations

Materials with random microstructure are characterized by additional thermodynamic parameters, entropy and temperature of microstructure. It has been argued that there is one more law of thermodynamics: entropy of microstructure decays in isolated systems. This assertion has been checked experimentally for the process of grain growth which showed that entropy of grain structure decays indeed as expected. The equation of state for microstructure entropy has also been studied. In general, entropy of grain microstructure is expected to be a function of grain structure energy and the average grain size. Our experiments suggest that in fact, the equation of state degenerates …

Characterization, Modeling, And Thermal Management Of High-Performance Lithium Batteries, Minjun Bae

Wayne State University Theses

Lithium-ion (Li-ion) batteries, as one of the most advanced commercial rechargeable batteries, play a crucial role in modern society as they are extensively used in portable electronic devices. Nevertheless, the limited electrochemical performance and poor thermal management systems of Li-ion batteries have hindered the expansion of their future applications. In search of alternative electrode materials to develop a battery with higher electrochemical performance, lithium (Li) metal has attracted much attention as an ideal alternative anode material due to its high specific capacity and lowest redox potential. However, needle-like Li dendritic growth causes severe safety concerns and thus prohibits practical applications …

Rare-Earth-Activated Group Vi D0 Metal Oxides As Thermosensitive Phosphors, Samarage Sameera Perera

Wayne State University Dissertations

ABSTRACT

RARE-EARTH-ACTIVATED GROUP VI d0 METAL OXIDES AS

THERMOSENSITIVE PHOSPHORS

by

SAMARAGE SAMEERA PRASAD PERERA

AUGUST 2019

Advisor: Dr. Federico A. Rabuffetti

Major: Chemistry

Degree: Doctor of Philosophy

Thermosensitive phosphors are solid-state materials that demonstrate distinct dependence of luminescence emission on temperature. These materials enable optical temperature sensing in environments where conventional thermometry is not possible (e.g., gas turbines, combustion engines, surface temperature distributions). However, the design of thermosensitive phosphors that show adequate sensitivity and low thermal quenching in the intermediate temperature range (i.e., 500–1000 K) remains challenging. This challenge can be addressed by understanding how to rationally manipulate the …

Fundamental Insights On The Electrolysis Of Co2 Using Solid Oxide Electrolysis Cells, Juliana Silva Alves Carneiro

Wayne State University Dissertations

The work reported in this thesis focused on providing a fundamental understanding, at the molecular level, required to guide the effective design of electrocatalysts towards a superior reaction kinetics on the electrode of solid oxide electrolysis cells SOECs devices (SOECs) during the CO2 electrolysis. High temperature SOECs are electrochemical energy conversion technologies, that have emerged as promising alternatives to mitigate environmental issues associated with combustion-based technologies, such as the rising atmospheric CO2 levels. The conversion of excess CO2 into high-energy molecules, such as CO can be efficiently achieved through the use of SOEC – which facilitates the electrochemical reduction of …

Synthesis Of Volatile And Thermally Stable Aluminum Hydride Complexes And Their Use In Atomic Layer Deposition Of Metal Thin Films, Kyle Blakeney

Wayne State University Dissertations

The research discussed in this dissertation spans both synthetic inorganic and nanomaterials chemistry. Aluminum hydride complexes have been synthesized and characterized which are highly volatile and thermally stable and their potential as reducing agents for ALD of electropositive metal and metal-containing films was evaluated. A major discovery has been the deposition of aluminum metal films by thermal ALD using an aluminum dihydride complex supported by a simple amido-amine ligand (Chapters 2). Aluminum is the most electropositive element deposited by purely thermal ALD to date and represents a significant breakthrough for this field. This process may have important industrial applications and …

Synthesis Of Discrete Transition Metal (Ni, Fe, Co, Mn) Phosphide Nanoparticles: Compositional Effect On Catalytic And Magnetic Properties, Da Li

Wayne State University Dissertations

This dissertation research is focused on the synthesis, characterization of binary and ternary transition metal (Ni, Co, Fe, Mn) phosphide nanomaterials and their catalytic and magnetic properties.

A phase-control strategy enabling the arrested-precipitation synthesis of nanoparticles of Ni5P4 and NiP2 is presented. The composition and purity of the product can be tuned by changing key synthetic levers, including the metal precursor, the oleylamine (OAm) and Trioctylphosphine (TOP) concentrations, temperature, time and the presence or absence of a moderate temperature soak step to facilitate formation of Ni and/or Ni-P amorphous nanoparticle intermediates.

New CoxFe2-xP nanoparticles (0 ≤ x ≤ 2), Co2-xMnxP …

Novel Design And Synthesis Of Transition Metal Hydroxides And Oxides For Energy Storage Device Applications, Peifeng Li

Wayne State University Theses

Supercapacitors (SCs) and Li-ion batteries (LIBs) are two types of important electrical energy storage devices with high power density and high energy density respectively. However, to satisfy the increasing demand of high-performance energy storage devices, the energy density of SCs and power/energy densities of LIBs have to be further improved. The exploration, research, and development of electrode materials with high-performance for applications in SCs and LIBs are still needed to meet the ever-increasing demand on energy and power densities. Herein, the amorphous Ni-Co-Mo ternary hydroxides nanoflakes for SCs and oxides nanoflakes for LIBs with ultrathin stature, abundant open spaces, and …

Dielectric Anomalies Of Both Chiral And Achiral Nematogens Near The Isotropic To Mesogenic Phase Transition, Garrett Justin Godfrey

Wayne State University Dissertations

The dielectric properties of nematic liquid crystals were studied in both the achiral and chiral limits. For achiral nematics, the literature documents that pretransitional curvature occurs for polar molecules on both sides of the nematic and isotropic phase transition. This curvature is due to anti-parallel dimer formation. However, past models have failed to quantitatively describe pretransitional curvature. Through a generalization of the order parameter, a macroscopic model has been developed to mathematically describe the pretransitional curvature on the isotropic side of the transition. The new model was fitted to dielectric data from the literature. Meaningful parameter estimates were extracted.

The …

Substrate Effects And Dielectric Integration In 2d Electronics, Bhim Prasad Chamlagain

Wayne State University Dissertations

The ultra-thin body of monolayer (and few-layer) two dimensional (2D) semiconducting materials such as transitional metal dichalconiges (TMDs), black phosphorous (BP) has demonstrated tremendous beneficial physical, transport, and optical properties for a wide range of applications. Because of their ultrathin bodies, the properties of 2D materials are highly sensitive to environmental effects. Particularly, the performance of 2D semiconductor electronic devices is strongly dependent on the substrate/dielectric properties, extrinsic impurities and absorbates. In this work, we systematically studied the transport properties of mechanically exfoliated few layer TMD field-effect transistors (FETs) consistently fabricated on various substrates including SiO2,Parylene –C, Al2O3, SiO2 modified …

New Chemistry For The Growth Of First-Row Transition Metal Films By Atomic Layer Deposition, Joseph Peter Klesko

Wayne State University Dissertations

Thin films containing first-row transition metals are widely used in microelectronic, photovoltaic, catalytic, and surface-coating applications. In particular, metallic films are essential for interconnects and seed, barrier, and capping layers in integrated circuitry. Traditional vapor deposition methods for film growth include PVD, CVD, or the use of plasma. However, these techniques lack the requisite precision for film growth at the nanoscale, and thus, are increasingly inadequate for many current and future applications. By contrast, ALD is the favored approach for depositing films with absolute surface conformality and thickness control on 3D architectures and in high aspect ratio features. However, the …

Multiferroicity In Iron Vanadate, Magnetite And Polyvinylidene Fluoride Nanocomposite Films, Ehab Hamdy Abdelmonaim Abdelhamid

Wayne State University Dissertations

With the increasing demand on cheaper and better performance multifunctional materials for different applications, it is becoming more crucial to have a better understanding of the physics needed to tailor more devices and materials to fit better in every day’s technological needs. Materials which show more than one ferroic order simultaneously –namely, multiferroics– are of particular importance for their potential applications as multiple state memory elements, transducers and electrically tunable microwave devices.

In this work, we studied FeVO4 single crystals as an example on low symmetry multiferroics. We focused on the anisotropy in those crystals in an attempt to nail …

Novel Design And Synthesis Of Structured Iron Oxides For Battery Applications, Jian Zhu

Wayne State University Dissertations

Lithium-ion batteries (LIBs) are currently the dominant powder source for personal computers and portable electronics. LIBs also play important roles in larger-scale applications, including electric drive vehicles (EVs, HEVs) and grid-energy storage. To meet the increasing demand for energy storage, it is very urgent and crucial to develop next-generation LIBs using alternative electrode materials. For example, carbon is still exclusively used as anode materials in current LIBs. However, the theoretical capacity of graphite (372 mA h g–1 based on LiC6) has almost been achieved, and it becomes one of the bottlenecks to further increase the energy density of LIBs based …

Study Of Tin-Based Electrodes And Ionic Liquid Electrolytes For Energy Storage Materials, Mahbuba Ara

Wayne State University Dissertations

Due to rapid increase in energy demand, modern society necessitates to develop high power, light-weight, and more economical energy storage systems. Rechargeable Li-ion batteries and Li-oxygen batteries have become the most promising energy devices in terms of energy and power densities. Diverse research on these battery components is being carried out by researchers worldwide to improve power density to meet the future requirements. The possible routes to improving power density of Li-ion as well as Li-oxygen batteries is to use nanostructured, hybrid electrode materials since they can significantly enhance kinetics of electrochemical reactions; and ion-conducting, low volatile electrolytes since they …

Synthesis And Characterization Of Transition Metal Arsenide Nanocrystals And The Metastability And Magneto-Structural Phase Transition Behavior Of Mnas Nanocrystals, Yanhua Zhang

Wayne State University Dissertations

This dissertation study focuses on (1) probing the magneto-structural phase transformation in nanoscale MnAs; (2) evaluation of the size-dependent phase stability of type-B MnAs (prepared by rapid injection); and (3) developing a general synthetic method for transition metal arsenide nanoparticles.

Discrete MnAs nanoparticles that adopt different structures at room temperature (type-A, α-structure and type-B, β-structure) have been prepared by the solution-phase arrested precipitation method. Atomic pair distribution and Rietveld refinement were employed on synchrotron data to explore the structural transitions of the bulk and nanoparticle samples, and these results were compared to AC magnetic susceptibility measurements of the samples. The …

Green Diesel Production Via Catalytic Hydrogenation/Decarboxylation Of Triglycerides And Fatty Acids Of Vegetable Oil And Brown Grease, Elvan Sari

Wayne State University Dissertations

Increase in the petroleum prices, projected increases in the world’s energy demand and environmental awareness have shifted the research interest to the alternative fuel technologies. In particular, green diesel, vegetable oil/animal fat/waste oil and grease derived hydrocarbons in diesel boiling range, has become an attractive alternative to biodiesel— a mixture of fatty acid methyl esters, particularly due to its superior fuel properties that are similar to petroleum diesel. Hence, green diesel can be used as a drop-in fuel in the current diesel engines. The current technology for production of green diesel– hydrodeoxygenation of triglycerides and fatty acids over conventional hydrotreating …

Fabrication Of Two-Dimensional Nanostructures On Glass Using Nanosphere Lithography, Elmer Jim Wang

Wayne State University Theses

It is desired to have artificial optical materials with controllable optical properties. Optical glass is the most common optical material for various applications. This research will attempt to create a thin layer on the substrate with controllable optical properties. The thin layer is a composite material with nanoscale features and controllable refractive index. Two-dimensional (2D) nanostructures will be created on the surface of optical glass using nanosphere lithography. In comparison with conventional techniques, this approach is more efficient and cost-effective for the creation of large areas of thin surface layers as an artificial material. A uniform monolayer of nanospheres will …

Nano-Silicon/Graphene Composite Anodes For Enhanced Performance Lithium Ion Batteries, Rhet Joseph Caballes De Guzman

Wayne State University Dissertations

The ever evolving technological applications such as with portable electronics and electric vehicles have led to increasing energy demands that have proven the existing commercial LIB capacity insufficient. Recently, the most promising anode material to substitute the traditional graphite is Si. As an anode Si has low discharge potential and theoretical the highest known theoretical capacity (>10 fold of graphite). However, due to the increased accommodated Li+ during charge-discharge reactions, silicon's volume varies up to 400%, causing pulverization and loss of electrical contact.

This dissertation focuses on a systematic approach in developing effective means to utilize Si for improved …

Multi-Component Ab2 Metal Hydride Alloys For Nickel Metal Hydride Battery Applications, Jean Nei

Wayne State University Dissertations

Compared to the mish metal-based AB₅ MH alloy commonly used in Ni/MH batteries, the transition metal-based AB₂ MH alloy not only reduces the rare earth dependency, it also has higher specific energy. In order to further improve the performance of AB₂ MH alloy, it's crucial to full understand its multi-phase nature, which includes the main C14/C15 Laves phases and the secondary non-Laves phases.

In order to optimize the gaseous phase and electrochemical advantages of both the C14 and C15 Laves phases, a study was established to recognize the factors that affect the C14/C15 phase abundance. Average electron …

New Precursors And Chemistry For The Growth Of Transition Metal Films By Atomic Layer Deposition, Thomas Joseph Knisley

Wayne State University Dissertations

The advancing complexity of advanced microelectronic devices is placing rigorous demands on currently used PVD and CVD deposition techniques. The ALD deposition method is proposed to meet the film thickness and conformality constraints needed by the semiconductor industry in future manufacturing processes. Unfortunately, there is a limited number of chemical precursors available that have high thermal stability, reactivity, and vapor pressure suitable for ALD film growth to occur. These properties collectively contribute to the lack of suitable transition metal precursors available for use in ALD. In this thesis, we report the discovery of a series of novel transition metal diazadienate …

Metal Chalcogenide Nanoparticle Gel Networks: Their Formation Mechanism And Application For Novel Material Generation And Heavy Metal Remediation Via Cation Exchange Reactions, Irina Ramona Pala

Wayne State University Dissertations

METAL CHALCOGENIDE NANOPARTICLE GEL NETWORKS: THEIR FROMATION MECHANISM AND APPLICATION FOR NOVEL MATERIAL GENERATION AND HEAVY METAL REMEDIATION VIA CATION EXCHANGE REACTIONS

by

IRINA R. PALA

February 2012

Advisor: Dr. Stephanie L. Brock

Major: Chemistry

Degree: Doctor of Philosophy

The dissertation research is focused on (1) uncovering the mechanism of metal chalcogenide nanoparticle gel formation; (2) extending the cation exchange reaction protocol to zinc sulfide gel networks, with the goal of accessing new aerogel chemistries and understanding the factors that drive the process; and (3) conducting a quantitative analysis of the ability of ZnS aerogels to remove heavy metal ions …

Effects Of Transition Metal Doping On Multiferroic Ordering In Ni3v2o8 And Fevo4, Akila Deeghayu Kumarasiri

Wayne State University Dissertations

We have studied the effects of doping both non-magnetic and magnetic ions on the phase transitions and multiferroic ordering in two multiferroic oxides; Ni3V2O8 and FeVO4. Magnetic, dielectric, specific heat, polarization and AC susceptibility measurements were used to track changes in phase transition temperatures. We found that the two higher temperature magnetic transitions in Ni3V2O8; TH = 9.1 K and TL = 6.3 K are suppressed to lower temperatures with all transition metal dopants. For Zn doping, the rates of the suppression of both TH and TL with dopant fraction are consistent with simple site dilution for two-dimensional spin systems, …

Electro-Optic And Magneto-Dielectric Properties Of Multifunctional Nitride And Oxide Materials, Ambesh Dixit

Wayne State University Dissertations

ABSTRACT

Materials that simultaneously exhibit different physical properties provide a rich area of research leading to the development of new devices. For example, materials having a strong coupling between charge and spin degrees of freedom are essential to realizing a new class of devices referred to generally as spintronics. However, these multifunctional systems pose new scientific challenges in understanding the origin and mechanisms for cross-control of different functionalities. The core of this Ph.D. dissertation deals with multifunctional nitride and oxide compound semiconductors as well as multiferroic magnetic oxide systems by investigating structural, optical, electrical, magnetic, magnetodielectric and magnetoelectric properties.

Thin …