Physical Sciences and Mathematics Commons^™

Measurements Of Rate Exchange Dynamics In Supercooled Ortho-Terphenyl By Single-Molecule 3d Kinetics And Green’S Functions, Harveen Kaur

Theses and Dissertations

Heterogeneity in relaxation rates is a well-established feature of supercooled liquids. It implies the existence of a rate-exchange process to restore ergodicity, but the experimental characterization of that exchange has been incomplete and controversial. This dissertation develops three-dimensional (3D) correlation functions that provide a well-defined measure of rate exchange from single-molecule measurements. This approach is demonstrated on both single-molecule dichroism measurements and atomistic simulations of molecular rotation in ortho-terphenyl.

The first project develops non-parametric analysis of nonexponential and multidimensional kinetics. The quantification of nonexponential (dispersed) kinetics has relied on empirical functions, which yield parameters that are neither unique nor easily …

Synthesis And Design Of Novel Polymer Grafted Nanoparticles Relevant To Drug Delivery Vehicles For Biomedical Applications, Maan Abduldiyem Hassan Al-Ali

Theses and Dissertations

The modification of inorganic nanoparticles with organic polymer chains has become a significant field of study for the engineering of advanced nanocomposite materials. This dissertation presents the design, synthesis, and characterization of novel polymer grafted silica nanoparticles as new strategies to combat bacterial resistance. Described herein is the synthesis of monomers that have been graft polymerized onto silica nanoparticles that can be used as a delivery drug vehicle for biomedical applications. The polymerization of these monomers was performed via reversible addition-fragmentation chain transfer (RAFT) polymerization. The molecular design of the RAFT agents that are attached to the surfaces of the …

A Novel Analytical Method For Studying Pharmacological Treatments For Affective Disorders In Neuroscience, Shane N. Berger

Theses and Dissertations

Histamine and serotonin are important neurochemicals that maintain crucial brain functions. Both are thought to be altered in affective and neurodegenerative disorders such as depression and Parkinson’s disease. Histamine and serotonin are thought to modulate one another but the exact relationship remains unknown and this gap in knowledge makes diagnosing and treating disorders involving the transmitters difficult. The Hashemi lab studies serotonin neurochemistry to understand serotonin’s role in psychiatric disorders. However, histamine has remained an understudied neurotransmitter due to a lack of analytical tools. In 2015 and 2016, the Hashemi lab pioneered a novel detection method utilizing fast-scan cyclic voltammetry …

Exploratory Molten Flux Crystal Growth Of Complex Uranium Oxides, Christian A. Juillerat

Theses and Dissertations

While the use of nuclear technology has proven useful for energy generation and for military use, the proper disposal and storage of the resulting nuclear waste requires serious attention to ensure radioactive species are indefinitely sequestered to protect the biosphere. There are several classifications of nuclear waste such as spent nuclear fuel (from industrial power plants), low level waste (slightly contaminated trash), and high level waste (HLW) which is in the form of a sludge, precipitated salt, or liquid. Each of these requires a different approach to processing and storage. Of these, HLW requires the most attention because it is …

Disinfection Byproduct Drivers Of Cytotoxicity In Drinking Water And Swimming Pools, Joshua M. Allen

Theses and Dissertations

Water disinfection was cited as the greatest public health achievement of the 20th Century. By inactivating pathogens, disinfection has significantly reduced waterborne diseases in drinking water and swimming pools. However, chemical disinfection has also raised a public health issue: the potential for cancer induction, reproductive and developmental effects, and asthma-related risks associated with exposure to chemical disinfection byproducts (DBPs), which are formed by the reaction of disinfectants with organic matter (natural or anthropogenic), bromide, and iodide. In the U.S., four trihalomethanes (THMs) and five haloacetic acids (HAAs) are currently regulated in drinking water, although no DBPs are regulated in pools, …

Hydrogen Peroxide And Antioxidant Enzymes Moderate Interaction Of The Carbon And Oxygen Cycles At The Redoxcline, Fan Wang

Theses and Dissertations

Hydrogen peroxide is a reduced form of dioxygen produced in natural waters from a manifold of abiotic and biological processes. Hydrogen peroxide is highly redox active and it often serves to initiate the formation of reactive oxygen species in the environment. It typically exists in natural waters at concentrations ranging from as low as ~ 1 nanomolar in “blue water” marine environments to as high as 10 micromolar near actively effluxing sediments. It has the potential to cause significant toxicity in aquatic organisms, which have evolved a collection of antioxidant enzymes including peroxidase, catalase, and superoxide dismutase. Work in this …

Protein Co-Assembly And Its Application In Enzyme Engineering, Libo Zhang

Theses and Dissertations

Enzymes, as highly efficient biocatalysts, have been researched extensively in both academia and industry because of their distinct advantages including high substrate specificity, high regio- and stereoselectivity, environmentally benign process, etc. Though enzyme catalysis has been scaled up for commercial processes in the pharmaceutical, food and beverage and detergent industries, technical barriers associated with enzyme implementation persist, i.e., low catalytic efficiency at non-natural environment, exhausting product separations, high cost of certain enzymes, etc. Moreover, currently most industrial enzymes are used in single-step reactions; however, multistep and multienzyme catalysis with optimal efficiency could greatly expand its potential for synthetic applications to …

Tailored Multifunctional Heterometallic Metal-Organic Frameworks, Otega Anthonia Ejegbavwo

Theses and Dissertations

Metal-organic frameworks (MOFs), which are well-defined and porous extended structures consisting of organic linkers connected to inorganic secondary building units, are a class of materials that have received tremendous attention over the last decade. This geometrically growing interest in MOFs is attributed to their properties of porosity, tunability, modularity, crystallinity, flexibility, and long-term stability, which makes them attractive candidates for various applications. This dissertation focuses on two major studies, the first part encompasses the strategic design, preparation, and extensive studies of actinide containing MOFs (An-MOFs). This work, presented within the first two chapters, demonstrates the effective utilization of MOF modularity …

Fundamental Studies Of Bimetallic Model Surfaces And Metal Organic Framework Thin Films, Fathima Sharfa Farzandh

Theses and Dissertations

This work is mainly focused on gaining a fundamental understanding of conventional bimetallic catalysts in order to correlate their macroscopic properties with the observed kinetic properties. This is achieved by synthesizing and studying fundamental model surface analogues of conventional catalysts that are difficult to study due to their complex, ill-defined nature. A wide array of surface science techniques that use ultra-high vacuum (UHV) conditions are readily available for detailed studies that can be conducted on model surfaces. This work focuses on the synthesis and investigation of two fundamental bimetallic catalysts formed via the addition of a second metal to an …

Chemistry Of A Biscarborane Dithiol And Its Nickel (Ii) Complex, Tyler Hemingway

Theses and Dissertations

Neutral biscarborane dithiol and its anionic dithiolate form were successfully synthesized and structurally characterized. The C–C intracluster bond lengths were found to be responsive to the electron density on the cluster. Introduction of two thiol groups on biscarborane led to the significant increase of intracluster C–C bond lengths compared to those of unsubstituted biscarborane. Furthermore, the anionic dithiolate form had even longer C–C cluster bonds. This comparison shows electronic effect of substituents attached to carbon atoms of biscarborane on the strength of its C–C bonds. Additionally, a novel Ni complex was obtained using this dithiolate as a ligand. This complex …

Systematic Development Of Photocatalysts, Mary Victoria Bobo

Theses and Dissertations

Photocatalysis is a rapidly growing field and a powerful synthetic tool that has recently seen many advancements, showing immense promise to replace classic catalysis with a mild and elegant alternative methodology. Visible light driven catalysis relies on redox stable transition metal and organic based photoactive catalysts (photocatalysts) that absorb visible light efficiently and facilitate electron/energy transfer. The desire for greener and more renewable catalytic methods has caused research to shifted away from traditional transition metals (due to scarcity and environmental toxicity) and toward organic based photocatalysts. Due to similar photophysical and electrochemical characteristics of each of these classes of photocatalysts …

Development Of Natural Product-Derived Cationic Polymers For Biomaterial Applications, Moumita Sharmin Jui

Theses and Dissertations

In this thesis, multicyclic natural products and metallocene-containing polymers were synthesized for biomedical applications.

Chapter 1 describes the overall background, the recent development of natural product-based antimicrobial biomaterial and metallocene containing polymer for biomedical application. Afterward, the primary research objectives of my research are illustrated.

In chapter 2, a multicyclic natural product derived guanidine-based facially amphiphilic homopolymers and copolymers were synthesized. Cholic acid is one of the bile acid derivatives used to prepare facially amphiphilic moieties. A neutral polyethylene glycol (PEG) component was used to prepare copolymers with cholic acid. Reversible-addition fragmentation chain transfer (RAFT) polymerization technique was used to …

An Examination Between Neighborhood Characteristics And Alzheimer’S Disease And Related Dementias And Caregiver Mental Health In South Carolina, Mohammad Jahirul Islam

Theses and Dissertations

Carboranes are of topical interest due to their unique structures and applications in the fields of catalysis, polymers, material sciences and supramolecular chemistry. Icosahedral closo-dicarbadodecaboranes are remarkably robust three-dimensional boron-carbon clusters with two slightly acidic C-H bonds. Moreover, coordinatively unsaturated transition-metal complexes containing C-functionalized ortho-carborane are considered as potential catalysts for activation of small molecules.

Recently, we reported the synthesis of a pyridine-backbone pincer complex {(C₅H₃N)(C₂B₁₀H₁₀)₂}Ni(CH₃CN) (1) in which two C-functionalized ortho-carborane clusters act as the arms of the pincer ligand. The complex …

Structural, Functional And Immunological Studies Of Group 1 And 2 House Dust Mite And Profilin Allergens For The Development Of Allergen Specific Diagnostics And Immunotherapy, Anyway B. Kapingidza

Theses and Dissertations

Group 1 and 2 house dust mites (HDM) allergens elicit IgE response in more than 80% of sensitized individuals. These allergens affect 10-30% of the world’s population. Prolonged inhalation of low doses of allergens (microgram amounts inhaled over months or years) by genetically predisposed individuals leads to the induction of a Th2-type immune response induced by allergen-specific immunoglobulin E (IgE) produced by plasma cells resulting in allergic diseases like asthma, atopic dermatitis, and rhinitis. Group 1 and 2 HDM allergens, in particular, are associated with the development of the aforementioned allergic diseases. The goal of this research was to characterize …

Gel Permeation Chromatography Purification And Surface Chemistry Of Technologically Relevant Colloidal Quantum Dots, Adam Roberge

Theses and Dissertations

Semiconductor quantum dots have received extensive research interest due to the size tunable band gap, large extinction coefficient, and ease of synthesis. These nanocrystals possess large surface to volume ratios and the chemistry at the surface of the nanocrystal greatly influences the resultant optoelectronic properties. Therefore, after synthesis, purification of the quantum dot samples to remove synthetic by-products that may alter these properties is of great importance. Gel permeation chromatography (GPC), a form of size exclusion chromatography, has been shown to reproducibly purify CdSe quantum dots. This work focuses on the expansion of purification by gel permeation chromatography to other …

Fundamental Studies Of Bimetallic Model Surfaces And Metal Organic Framework Thin Films, Fathima Sharfa Farzandh

Theses and Dissertations

This work is mainly focused on gaining a fundamental understanding of conventional bimetallic catalysts in order to correlate their macroscopic properties with the observed kinetic properties. This is achieved by synthesizing and studying fundamental model surface analogues of conventional catalysts that are difficult to study due to their complex, ill-defined nature. A wide array of surface science techniques that use ultra-high vacuum (UHV) conditions are readily available for detailed studies that can be conducted on model surfaces. This work focuses on the synthesis and investigation of two fundamental bimetallic catalysts formed via the addition of a second metal to an …

A Behavioral And Voltammetric Study Of The Effects Of Pb Exposure In Mice As A Model Of Autism Spectrum Disorder, Brenna Parke

Theses and Dissertations

Despite being a known toxin for several centuries, lead (Pb²⁺) is still utilized in commercial products including leaded gasoline, paint, and modern cosmetics. This presence has caused (Pb²⁺) to pollute the environment, including public drinking water sources. The recent outbreaks of elevated levels of (Pb²⁺) in the drinking water in Flint, Michigan and Washington D.C. have caused large populations to be exposed to the heavy metal for months at a time, raising a public health concern over the implications of widespread, long-term (Pb²⁺) exposure. Young children are most susceptible to the effects …

Investigating The Role Of Iron-Sulfur Signaling In Yeast Transcriptional Regulation, Malini Gupta

Theses and Dissertations

As an essential cofactor in a myriad of cellular processes, uptake and mobilization of iron must be tightly controlled. Iron homeostasis in fungi involves balancing iron uptake and storage with iron utilization to achieve adequate, non-toxic levels of this essential nutrient. Extensive work in the non-pathogenic yeasts Saccharomyces cerevisiae and Schizosaccharomyces pombe have uncovered unique iron regulation networks for each organism that control iron metabolism via distinct molecular mechanisms. The activities of all fungal iron-sensing transcription factors characterized to date are regulated via iron-sulfur cluster signaling.

In Saccharomyces cerevisiae, expression of iron uptake, utilization and storage genes is primarily regulated …

Mechanistic Investigations Of Isothiourea Catalyzed Silylations Of Secondary Alcohols Using Reaction Progress Kinetic Analysis, Brandon Kane Redden

Theses and Dissertations

The primary focus of this research is in expanding the knowledge and scope of the asymmetric silylation of alcohols. Since it was discovered in 2011 that chiral isothioureas can selectively silylate alcohols through kinetic resolution reactions, the Wiskur group has been working to increase the applications of the methodology. Understanding the kinetics behind the mechanism of the reaction is fundamental in the designing both improved kinetic resolutions and other silylation methodology. Chapter 2 focuses on using reaction progress kinetic analysis to monitor silylations of secondary alcohols with thiourea catalysts in real time using in situ IR to determine the rate …

Synthesis And Design Of Novel Polymer Grafted Nanoparticles Relevant To Drug Delivery Vehicles For Biomedical Application, Maan Abduldiyem Hassan Al-Ali

Theses and Dissertations

The modification of inorganic nanoparticles with organic polymer chains has become a significant field of study for the engineering of advanced nanocomposite materials. This dissertation presents the design, synthesis, and characterization of novel polymer grafted silica nanoparticles as new strategies to combat bacterial resistance. Described herein is the synthesis of monomers that have been graft polymerized onto silica nanoparticles that can be used as a delivery drug vehicle for biomedical applications. The polymerization of these monomers was performed via reversible addition-fragmentation chain transfer (RAFT) polymerization. The molecular design of the RAFT agents that are attached to the surfaces of the …