Physical Sciences and Mathematics Commons^™

Ultra-Stable Protein-Polymer Bioconjugates, Kyle S. Cole

Master's Theses

No abstract provided.

Confinement Effects Of Solvation On A Molecule Physisorbed On A Metal Particle, Jacob Fosso Tande

Doctoral Dissertations

We describe and present results of the implementation of the surface and volume polarization for electrostatics~(SVPE) and the iso-density surface solvation models. Unlike most other implementation of the solvation models where the solute and the solvent are described with multiple numerical representation, our implementation uses a multiresolution, adaptive multiwavelet basis to describe both solute and the solvent. This requires reformulation to use integral equations throughout as well as a conscious management of numerical properties of the basis.

Likewise, we investigate the effects of solvation on the static properties of a molecule physisorbed on a spherical particle, modeled as a polarizable …

Synthesis Of Palladium-Based Electrocatalysis—From Pure Metal To Bimetallic Nanoparticles, Haijun Gao

Masters Theses

This thesis focuses on synthesis and characterization of palladium-based nanoparticles. Background information of the research in this thesis is provided in Chapter 1. Preparation and characterization of pure palladium nanoparticles are presented in Chapter 2. A fast and convenient method to prepare ultra small Pd nanoparticles via Pluronic P123 reduction is discussed in detail. Impregnation method and poly method are also studied in this chapter. Chapter 3 reports the studies of these methods to prepare ultra small bimetallic (bimetallic means a mixture of two metals) palladium-based nanoparticles. Oleylamine-mediated method used Pd nanoparticles prepared via P123 reduction as precursor. Ultra small …

The Effects Of Color Concentrates On The Rheology Of Tint Bases, Doug James Herrick

Master's Theses

ABSTRACT

THE EFFECTS OF COLOR CONCENTRATES ON THE RHEOLOGY OF TINT BASES

Douglas James Herrick

Waterborne coatings are formulated with a number of different ingredients; water, latex polymers, pigments, surfactants, dispersants, defoamers, biocides, coalescing aids, and rheology modifiers or thickeners. Rheology modifiers are necessary in order to improve the physical properties of the coating before, during, and after application to a substrate. There are two kinds of rheology modifiers used in waterborne coatings; associative thickeners and non-associative thickeners. Coatings formulated with associative thickeners are quite sensitive to coating variations; the slightest change in the formulation has profound effects on the …

In Situ Measurements Of Electron-Beam-Induced Surface Voltage Of Highly Resistive Materials, Joshua Hodges

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Surface charging and subsequent electrostatic discharge due to interactions with the space environment is one of the primary concerns of spacecraft charging studies. Laboratory measurements of the evolution of surface voltages and dissipation currents under simulated space conditions are the primary method used to determine the response of key spacecraft materials to diverse incident fluxes. Increasing the database of information for the electronic properties of insulating materials can assist spacecraft designers in mitigating the harsh effects of the space environment.

The Utah State Materials Physics Group, with the funding of the NASA James Webb Space Telescope project and personnel support …

Studies On Molecular Sieve Crystallization And Heteroatomic Substitution, Adam R. Macintosh

Electronic Thesis and Dissertation Repository

Molecular sieves have been scientifically and industrially important materials since their inception. These porous, crystalline networks of tetrahedrally coordinated atoms bridged by oxygen are known for their extremely high surface area and low density, making them excellent systems for catalysis. The framework of the AlPO₄ family of molecular sieves is itself non-catalytic, but through heteroatomic substitution these materials can diversify into the catalytically active silicoaluminophosphate (SAPO) and metalloaluminophosphate (MAPO) families of heterogeneous acid and redox catalysts. Research into the methods by which these substitutions occur, and the effects therein on the crystallization of the sieves, is of great importance, …

Studies Of Microscopic Scale Strains In Nickel Alloys Resulting From Mechanical And Chemical Forces, Jing Chao

Electronic Thesis and Dissertation Repository

The nickel-based Alloy 600, also known as Inconel 600 has been found to be susceptible to stress corrosion cracking (SCC) in high temperature aqueous environments. Despite extensive research, the mechanisms by which this process occurs remain in question. It is known that SCC results from the simultaneous effects of a chemically corrosive environment and a tensile stress. Many studies have been conducted on the microscopic chemical changes associated with SCC. There have been fewer studies of the microscopic stress/strain process. The main objective of this thesis is to use the new x-ray based diffraction technique – polychromatic x-ray microdiffraction (PXM) …

Ionothermal Synthesis Of High Silica Zeolites In Deep Eutectic Solvents (Des), Zheng Sonia Lin

Electronic Thesis and Dissertation Repository

Phase-pure high silica zeolites have been synthesized using different deep eutectic solvents for the first time. ZSM-5 was made in tetrapropylammonium bromide/pentaerythritol. The reaction is affected by the amounts of seeding, water content, and organic structure-directing agent (SDA). Sodalite and ZSM-39 were prepared in tetramethylammonium chloride (TMACl)/1, 6-hexanediol by using the mineralizing agents NaOH and NH₄F, respectively. In urea/choline chloride, ZSM-5, Beta, ZSM-39, and ZSM-11 were made by using different organic SDAs in the presence of fluoride. The reaction temperature and the choice of organic SDA affect the type of structures being produced.

The crystallization of ZSM-39 in …

Synthesis Of Silicide Nanomaterials Using Chemical Vapour Deposition Method, Hamid Norouzi Banis

Electronic Thesis and Dissertation Repository

Recent research has evidenced that nanotechnology may bring about a material revolution which sweeps through different scientific fields and leads to dramatic changes in the use of natural resources and our everyday life. Compared to their bulk counterparts, the nanomaterials may exhibit significantly improved physical properties by shrinking their size to nanometer scale. Metal silicide are distinguished by their features of combining advantages of both metals and semiconductors which promises superior performance various fields. Despite the progress in the synthesis methods of nanomaterials, it still remains a big challenge in controlled synthesis of 1D silicide nanostructures due to the difficulties …

Surface Functionalized Water-Dispersible Magnetite Nanoparticles: Preparation, Characterization And The Studies Of Their Bioapplications, Haiou Qu

University of New Orleans Theses and Dissertations

Iron oxide magnetic nanoparticle synthesis and their surface functionalization hold a crucial position in the design and fabrication of functional materials for a variety of biomedical applications. Non-uniform nanoparticles with poor crystallinity, prepared by conventional methods, have only limited value in biological areas. Large scale synthesis methods that are able to produce high quality, mono-dispersed iron oxide nanoparticles using low cost and environment friendly chemicals are highly desirable. Following synthesis, appropriate surface functionalization is necessary to direct the dispersibility of nanoparticles in aqueous solution in order to provide them with acceptable colloidal stability against the ion strength and many biomolecules …

Understanding The Thermodynamic Behavior Of Nanoparticles To Tailor Polymer Nancomposite Structure, Mary Catherine Mutz

Doctoral Dissertations

The work presented in this dissertation is an attempt to understand the entropic and enthalpic forces that govern the dispersion and dissolution of nanoparticles in solutions and in thin polymer films with the end-goal of producing highly tailored products.

In the first part, neutron reflectivity was used to study the impact of nanoparticle presence on the surface segregation of deuterated polystyrene (dPS) in a polystyrene matrix. The impact of the presence of cylinders (carbon nanotubes), sheets (graphene), and spheres (polystyrene soft nanoparticles) on the surface segregation process and ultimate structure were examined. Experimental data indicate that the presence of the …

Synthesis And Temperature-Induced Phase Transfer Behavior Of Thermosensitive Hairy Particles Between Aqueous Solution And A Hydrophobic Ionic Liquid, Jonathan Michael Horton

Doctoral Dissertations

This dissertation presents the synthesis of a family of thermosensitive polymer brush-grafted silica particles and the study of their thermally induced phase transfer behavior between water and a hydrophobic ionic liquid, 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)amide ([EMIM][TFSA]). The hairy particles were prepared by surface-initiated atom transfer radical polymerization.

Chapter 1 describes the synthesis and phase transfer behavior of a series of 205 nm silica particles grafted with thermosensitive polymers of methoxyoligo(ethylene glycol) methacrylates. The hairy particles with sufficiently high lower critical solution temperatures underwent reversible and quantitative transfer between water and [EMIM][TFSA] in response to temperature changes. The transfer temperature (T_{tr …}

Synthesis And Characterization Of Functionalized Nanomaterials: Heterogeneous Palladium Catalyst And Lithium-Doped Graphene Oxide, Benjamin E Estes

Doctoral Dissertations

As the Earth's population increases and natural resources decrease in supply, the development of new methods for energy storage and the efficient production of industrial chemicals becomes ever more important to humanity. The development of new nanomaterials may offer technological advances in the fields of sustainable energy production and storage, chemical production, medicine, and many others. The emerging field of nanoscience blends chemistry, physics, and engineering to create new materials that take advantage of properties found only on the nanoscale.

In this work, mesoporous silica spheres are used as a support for nanoparticles of palladium. This nanomaterial is shown to …

The Synthesis And Characterization Of Novel Group 13 Nanostructured Building Block Heterogeneous Silicate Catalysts, Joshua G. Abbott

Doctoral Dissertations

A building block approach and sequential addition methodology were utilized to prepare heterogeneous silicate catalysts containing atomically dispersed group 13 metal (B, Al, Ga) centers. The octa(trimethyltin) silsequioxane, Si8[sub]O12[sub](OSnMe3[sub])8[sub], was used as the building block for the synthesis of these materials. Reaction of the building block with a variety of group 13 metal chlorides led to the formation of cross-linked matrices. All prepared materials were characterized by gravimetric analysis, gas absorption, IR, and NMR. In addition, aluminum and boron samples where characterized by 27[sup]Al and 11[sup]B solid state NMR, and gallium samples were studied using x-ray absorption techniques.

Studies found …

Synthesis Of A Superlattice Structure Of Alternating Layers Of Antimony Telluride And Bismuth Telluride By Atomic Layer Deposition For Thermoelectric Applications, David Nminibapiel

Electrical & Computer Engineering Theses & Dissertations

Alloys composed of bismuth, antimony and telluride compounds exhibit very high figure of merit ZT values at relatively low temperatures, making them exceptional thermoelectric materials. Advancement in thermoelectric devices and applications hinges on increasing ZT, which is a ratio of the thermoelectric power factor to the thermal conductivity. One of the proposed avenues to achieving this goal is the use of low dimensional structures such as quantum wells, quantum dots, superlattices (SL) and nanolaminates to affect heat transport. SL structures can effectively confine charge carriers as well as scatter phonons which contribute significantly to thermal conductivity. In this thesis, the …

High-Pressure Study Of Molecular Solids And 1d Nanostructures By Vibrational Spectroscopy And Synchrotron X-Ray Diffraction, Zhaohui Dong

Electronic Thesis and Dissertation Repository

Pressure plays a critical role in regulating the structures and properties of materials. Since Percy Bridgeman was recognized by the 1946 Nobel Prize for his contribution to high-pressure physics, high-pressure research as an interdisciplinary area has attracted extensive attentions. Nowadays, the high-pressure research involves broad frontier areas, such as chemistry, physics, biology, material and earth science. For instance, brand new classes of inorganic materials of unusual stoichiometries and crystal structures, with wide range of optical, mechanical, electronic and magnetic properties, have been produced at high pressure. Pressure-induced structural transformations between crystalline and amorphous materials, as well as among insulators, conductors …

Development Of A Quantitative High Throughput Method For The Early Detection Of Corrosion On Coated Aluminum, Jeffrey Clayton Foster

Master's Theses

Eight fluorescent indicators were evaluated for their ability to detect the corrosion of aluminum metal substrates. The fluorophore Rhodamine-salicylaldehyde (RSA) was selected as a candidate for further study based on its ability to bind and detect aluminum ions at low concentrations, its selectivity for aluminum ions, its long-term stability, its solubility in our solvent-based epoxy formulation, and its compatibility with our testing method.

A recent publication suggested that an alternative method of fluorescence activation was possible—an acid-promoted ring opening that occurred in the absence of metal ions. To prove the capability of RSA to bind aluminum ions, thorough ¹H …

The Development Of Transparent, Processable, Thermally-Responsive Coatings, Christopher David Roland

Master's Theses

Polymer matrices are commonly used as guest-host systems for organic chromophores for use in non-linear optical materials. The chromophores must be aligned or poled in an electric field in order to impart anisotropy and non-linear activity to the material. This poling process raises several issues, the two largest being the eventual relaxation of the chromophores back into random orientations due to brownian motion, and high molecular weight polymer matrices limiting chromophore mobility during poling. The prevention of this relaxation process is an area of significant interest, especially in applications that require long term coating stability and activity. In this study, …

Complementary And Self-Complementary Hydrogen Bond Double Helical Complexes, Bhanu P. Mudraboyina

Electronic Thesis and Dissertation Repository

The design of artificial or synthetic strands that self-assemble to form double-helical complexes have been of great interest to chemists and researchers since the discovery of the double helical DNA structure in 1953 by Watson and Crick. Most of the complexes were self-complementary double-helical homodimers and while few heterodimer complexes are also known. The present thesis describes the design, synthesis and characterization of complementary and self-complementary hydrogen bond arrays built from heterocycles such as pyridine, thiazine dioxide and indole connected in different sequences. The sequence-based stabilities, insolubility issues, substitution and preorganization effects in these arrays have been studied in detail. …

Investigating The Electron Transport And Light Scattering Enhancement In Radial Core-Shell Metal-Metal Oxide Novel 3d Nanoarchitectures For Dye Sensitized Solar Cells, Gayatri Sahu

University of New Orleans Theses and Dissertations

Dye-sensitized solar cells (DSSCs) have attained considerable attention during the last decade because of the potential of becoming a low cost alternative to silicon based solar cells. Electron transport is one of the prominent processes in the cell and it is further a complex process because the transport medium is a mesoporous film. The gaps in the pores are completely filled by an electrolyte with high ionic strength, resulting in electron-ion interactions. Therefore, the electron transport in these so called state-of-the-art systems has a practical limit because of the low electron diffusion coefficient (D_n) in this mesoporous film …

Controlled Attachment Of Nanoparticles To Layered Oxides, Yuan Yao

University of New Orleans Theses and Dissertations

A series of oxide materials were modified with different nanoparticles (NPs). Novel cobalt@H₄Nb₆O₁₇ nanopeapod structures were fabricated and magnetic NPs modified oxide nanosheets and nanoscrolls were prepared. Both aqueous method and two-phase method were applied to prepare gold NPs onto oxide nanosheets, nanoscrolls and other nanocrystals.

The combination of H₄Nb₆O₁₇ nanoscrolls and cobalt NPs generate a novel method to fabricate nanopeapod structures. Cobalt NPs were synthesized in the presence of exfoliated H₄Nb₆O₁₇ nanosheets and the resulting magnetic chain structures, formed due to the dipole-dipole interaction, …

Active Response Of Polymer Materials From External Stimuli – Solvents And Light; Grafting Reactions On Perovskite Layers, Jianxia Zhang

University of New Orleans Theses and Dissertations

The active response of a series of polymeric materials was investigated. Both solvent activated and light activated thin films and wire systems show dynamic behaviors when exposed to different stimuli.

Solvent mediated fluxional behavior of polymer thin films involved extensive, rapid curling both on infusion and evaporation of good solvents. These films can be either lab-fabricated ones or commercial ones, and the curling behavior can be as fast as seconds. Conditions including polymer materials, chosen solvents, and film geometry can affect the behavior.

Methods that allowed for the creation and retention of distorted wire structures were also developed; the asymmetric …

Studies On The Preparation, Immobilization, And Luminescence Properties Of Zinc Oxide (Zno)Quantum Dots, Yasemin Hakat

Electronic Theses and Dissertations

Quantum dots are a part of very important our technological future because of their intriguing and useful properties. These properties are different in character from those of the corresponding bulk material. Quantum dots are inorganic artificial semiconductor nanocrystal whose electrons influence their physical and chemical properties. Zinc oxide quantum dots were synthesized through an ethanol based precipitation via colloidal synthesis method at various pH values. Various emission colors were obtained because the excited quantum dots of various sizes emitted specific wavelengths of light. The emission spectra indicated that the pH dependent quantum dots were successfully synthesized. Zinc oxide quantum dots …

Synthesis, Characterization And Self-Assembly Of Amphiphilic Block Copolymers, Xiaojun Wang

Doctoral Dissertations

This dissertation presents a review on state-of-the-art research of well-defined charged block copolymers, including synthesis, characterization, bulk morphology and self-assembly in aqueous solution of amphiphilic block polyelectrolytes. In Chapter 1, as a general introduction, experimental observations and theoretical calculations devoted towards understanding morphological behavior in charged block copolymer systems are reviewed along with some of the new emerging research directions. Further investigation of charged systems is urged in order to fully understand their morphological behavior and to directly target structures for the tremendous potential in technological applications. Following this background, in Chapters 2, 3, 4 and 5 are presented the …

Improving Analytical Utility Of Surface Enhanced Raman Spectroscopy Through Unique Lithographic Substrate Development, Sabrina Marie Wells

Doctoral Dissertations

Surface enhanced Raman spectroscopy (SERS) has the potential to be a useful analytical technique due to large signal enhancements. Unfortunately, SERS has several drawbacks, including a lack of reproducibility, which inhibits it from being a practical option. These large signals often arise from “hot spots” of extremely high enhancement on nanofeatured metallic substrates, the most common being comprised of aggregated silver colloid. It is difficult to reproducibly create these hot spots due to the randomness of the colloid substrates. However, through controlled substrate fabrication, many problems associated with SERS analysis can be overcome. Electron beam lithography (EBL) combined with reactive-ion …

Atomistic Simulations Of The Fusion-Plasma Material Interface, Mostafa Jon Dadras

Doctoral Dissertations

A key issue for the successful performance of current and future fusion reactors is understanding chemical and physical processes at the Plasma Material Interface (PMI). The material surfaces may be bombarded by plasma particles in a range of impact energies (1 eV - a few keV) and kept at a range of temperatures (300 - 1000 K). The dominant processes at the PMI are reflection and retention of impacting particles and sputtering (chemical and physical). Sputtering leads to surface erosion and pollution of the plasma, both of which degrade reactor performance. Retention influences the recycling of the plasma, and in …

Modern Approaches For Multifunctional Hydrolyzying Thiol-Ene Networks, Nicole Marie Mackey

Dissertations

Marine fouling has been an expensive and time-consuming process for navies and fishermen by the accumulation of marine algae and animals on artificial surfaces. Many coatings have been proposed to combat marine fouling in efforts to extend the lifetime of objects immersed in sea water. However, all coatings tested have either failed to resist fouling for a significant length of time or have released toxins into the environment. We have investigated an environmentally friendly approach to address the problem of marine fouling through the synthesis and preparation of a biocidal and a self-polishing coating. Both novel monomers were prepared containing …

The Synthesis And Characterization Of Novel Titanosilicates For Next Generation Hydrogen Storage, James R. Humble

Chancellor’s Honors Program Projects

No abstract provided.

Physical Adsorption Of Gases Onto Mesoporous Silica Material Sba-15, Sean C. Forrest

Chancellor’s Honors Program Projects

No abstract provided.

Kinetics Of O2 Reduction On Oxide-Covered Ni-Cr-Mo Alloys, Xiangrong (Sarah) Zhang

Electronic Thesis and Dissertation Repository

Ni-Cr-Mo alloys exhibit exceptional corrosion resistance and are widely used in chemical processing industries. The reliable performance of these alloys under extreme industrial conditions, are generally attributed to the presence of a passive film on the alloy surface. O₂ reduction is the most likely cathodic process able to sustain metal oxidation (corrosion) in industrial environments. However, the kinetics of O₂ reduction on these oxide-covered alloys has hardly been studied, despite the possibility it may be the rate controlling process for corrosion, especially localized corrosion. The objectives of this research are to characterize the properties of the oxide film …