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Synthesis, Characterization, And Redox Properties Of Select 1,4-Diazocine-6,11-Diones Towards An Electrochromic Dye-Set, Jeffrey Scott Richards

Open Access Theses & Dissertations

The daily consumption of personalized digital visual information depends on the current purview of electronic-based displays. Present manufacturers utilize modern technologies, such as LCD, OLED, QLED, and electronic ink, or "E Ink," in their devices to display text, pictures, and other forms of media to individual users. However, as modern society continues to rely on the use of digital displays, the demand for low-power alternatives will continue to rise as their application in varying scenarios is realized. Currently, "E Ink" technology continues to grow as the dominant solution in the e-readers and digital signage marketplace, and can even be seen …

A Sociocognitive Perspective On The Activation Of Productive Epistemic Resources In College Students' Understanding Of Chemical Equilibrium, Henk Steven Van Den Bogaard

Open Access Theses & Dissertations

Science education, particularly in higher education, has a content coverage problem: it has long been described as "a mile wide, an inch deep" in various consensus documents from the National Academies. In chemistry education, the most common general chemistry curriculum covers topics as chapters based on the popular Sienko and Plane 1960's general chemistry textbook. The limited time available in such fast-paced coverage may limit the instructor's modeling and assessment of key performances in developing a mechanistic understanding of complex chemistry phenomena. In this sociocognitive, qualitative investigation, general chemistry II students' responses to assessment prompts were used to activate cognitive …

Electrodeposition Of Gallium Nitride_Unraveling The Role Of Precursors, Deposition Conditions, And Substrate Effects For Semiconductor Applications, Mauricio Azier Leyva Aranzabal

Open Access Theses & Dissertations

Gallium nitride (GaN) is a wide-bandgap semiconductor noted for its remarkable optoelectronic and structural characteristics, rendering it a potential material for high-power, high-frequency, and optoelectronic device applications. This dissertation investigates the electrochemical synthesis of GaN thin films by potentiostatic and galvanostatic electrodeposition techniques using aqueous solutions of gallium nitrate (Ga(NO3)3), ammonium nitrate (NH4NO3), and auxiliary agents like potassium nitrate and urea. The main aim is to examine the essential elements affecting nitrogen incorporation and film shape while assessing electrochemical performance on various conductive substrates.A thorough investigation was performed to evaluate the impacts of electrodeposition duration, electrolyte pH, precursor molar concentrations, …

Development Of Porous Separators For Lithium-Ion Batteries Via 3d Printing And Thermally Induced Phase Separation, Abraham Enchinton

Open Access Theses & Dissertations

Additive manufacturing processes allow the development of custom-shape rechargeable batteries, but research in custom filaments for fused deposition modeling (FDM) of battery separators has remained limited until now. This study discusses the development and optimization of a composite thermoplastic filament feedstock to 3D print separator membranes. A number of post-processing steps - leveraging the thermally induced phase separation (TIPS) of the composite filament - are introduced in tandem with FDM to promote microporosity formation through the removal of the sacrificial diluent phase within 3D printed samples. Three distinct compositions of varying polymer/diluent ratios were developed and thoroughly investigated through thermogravimetric …

Hydrothermal Synthesis Of Single-Crystal Magnetic Oxides, Bhakti Patel

All Dissertations

Multifunctional materials are systems that have two or more properties of interest. Some of these features are polar axes, chirality, magnetic ions, triangular arrangements, and/or magnetically silent building blocks. Various combinations of these properties can result in chiral ferromagnetism, multiferroic magnetoelectric behavior, antiferromagnetism, and quantum spin liquids and spin ices. By tuning these structure-property relations, quantum computing, memory, and sensors may be created. Large single crystals allow for a better understanding of the magnetic behavior of these crystals since they can be oriented in a magnetic field. Inorganic single crystals have a wide range of applications but growing high-quality single …

Biophysical Studies Of Nucleic Acid - Small Molecule Recognition, Andrea Conner

All Dissertations

The presented work is a collection of studies performed to examine small molecule recognition of nucleic acids. Recognition of nucleic acids was examined using two types of small molecules: aminoglycosides and Hoechst dyes. Chapter One focuses on established experimental techniques (i.e. absorbance, isothermal titration calorimetry, flow cytometry, cell microscopy, etc.) in small molecule recognition of nucleic acids. The emphasis of studies in the group has been on two focus areas. (i) Thermodynamic characterization of mixed A-form and B-form DNA or RNA conformation with aminoglycosides, particularly neomycin-class. (ii) Characterization of new Hoechst-morpholine (HT-MO) derivatives’ interactions with nucleic acids.

Focus area (i) …

Synthesis Of Nanoparticles In Silicate Matrix And Stimuli Responsive Nanocomposite Polymer Films, Dimuthu Edirisinghe

All Dissertations

Interactions between aqueous metal ions and soluble silicates lead to the formation of insoluble metal silicate complexes that form nanoparticles via condensation polymerization. Metal silicates function as nanoreactors, effectively condensing metal ions into nano-sized particles that can undergo further chemical transformations. Core-shell nanostructures present an intriguing strategy for integrating materials with different properties. The silicate shell around the silver nanoparticles can be successfully infused with other metal ions, enabling subsequent reactions to tailor their properties. Silver nanoparticles exhibit strong interactions with light, surpassing other chromophores, including noble metal nanoparticles, due to their highly efficient surface plasmonic resonance. The unique optical …

Photochemical Transformations Of Crude Oil In Marine Environments: Temporal And Thermal Dynamics Of Oxygenated Photoproducts And Genotoxic Effects, Mohamed Elsheref

LSU New Orleans Theses and Dissertations

This dissertation investigates the photochemical transformation of different crude oil types in marine environments, focusing on the time and temperature dependency of the formation of oxygenated photoproducts and their potential genotoxic effects. Using electrospray ionization tandem mass spectrometry (ESI-MS/MS), we examined the time and temperature dependence of aldehyde and ketone oxocarboxylic acid photoproduct generation from crude oil-seawater systems under simulated solar irradiation. The study revealed a near-linear increase in photoproduct concentration over an 18-hour irradiation period, with production rates ranging from 0.6 to 69 µmol/hm² of oil surface. Temperature effects on photoproduct formation were complex, but generally showed increased total …

Functional Consequences Of Lysine Acetylation Of Phosphofructokinase Isozymes, Xinyu Lin, Nour Fatema, Qinglei Gan, Chenguang Fan

Chemistry & Biochemistry Faculty Publications and Presentations

Phosphofructokinase (Pfk) catalyzes the phosphorylation of fructose 6-phosphate and is a key regulatory point in the glycolysis pathway. Multiple lysine residues in both Pfk isozymes, PfkA and PfkB, have been identified to be acetylated in Escherichia coli by proteomic studies, but no studies have been implemented to further characterize these acetylation events. To investigate the role of Pfk acetylation, the genetic code expansion strategy was used to generate homogeneously acetylated Pfk variants at target lysine sites that have been reported to be acetylated in nature. We found that acetylation of K309 of PfkA and K27 of PfkB decreased PfK enzyme …

A Pure Rotational Spectroscopic Study Of Two Nearly-Equivalent Structures Of Hexafluoroacetone Imine, (Cf3)C=Nh, Daniel A. Obenchain, Beppo Hartwig, Daniel J. Frohman, Garry S. Grubbs, B. E. Long, Wallace C. Pringle, Stewart E. Novick, S. A. Cooke

Chemistry Faculty Research & Creative Works

Rotational spectra for hexafluoroacetone imine, the singly substituted 13C isotopologues, and the 15N isotopologue, have been recorded using both cavity and chirped pulse Fourier transform microwave spectrometers. The spectra observed present as being doubled with separations between each pair of transitions being on the order of a few tens of kilohertz which is consistent with a large amplitude motion producing two torsional substates. The observed splitting is most likely due to the combined motions of the CF₃ groups, for which the calculated barrier is small. However, no transitions between states could be observed and, similarly, no Coriolis coupling parameters …

Tailoring The Morphology Of Block Copolymers Via Solvent-Vapor Annealing, Bayleigh Madelin Loving

Honors Theses

Triblock polystyrene-polyisobutylene-polystyrene (PS-PIB-PS) copolymers have widespread applications from thermoplastic elastomers to protective coatings for ballistic applications. The incompatibility between the soft PIB and hard PS phases leads to phase separation and subsequent formation of morphological domains like lamellae and cylinders. The structures are stabilized by physical crosslinks, which can greatly improve the toughness of the triblock systems by preventing chain pullout during tensile deformation. We tailored the morphologies (achieving different morphologies with the same block copolymer) by changing the annealing conditions of the block copolymers. Solvent vapor annealing was used to selectively activate the mobility of a particular block, causing …

A Spectroscopic Survey Of Atmospheres Of Super-Earths, Luke Brust

Honors Theses

Recent research has made it possible to use spectroscopy to analyze the composition of the atmospheres of exoplanets, planets that orbit other stars. Most projects thus far have focused on the atmospheres of gas giants, as it is less challenging to observe them with available equipment. This project studies the atmospheres of four Super- Earths, planets that have a mass greater than the Earth but smaller than Neptune. This is accomplished by processing the raw spectroscopic data from the Hubble Space Telescope and modeling the atmosphere using the program 𝝉-Rex3. This survey found clear results from two of the selected …

Chemistry Education At The University Of Southern Mississippi Through Computation And Active Learning Methods, Sadie Pitre

Honors Theses

Education is one of the pillars of society. It evolves alongside scientific progress, shaping how students learn and engage with complex topics. The incorporation of new educational standards at The University of Southern Mississippi (USM) was implemented in two parts: through computational chemistry laboratory exercises for teaching laboratories and through the synthesis of organic molecules for research projects in an upper-level spectroscopy class. The goal of these projects is to improve learning of abstract and/or complex topics beyond the teaching methods traditionally utilized in the undergraduate laboratory and in the classroom.

Computational chemistry, which uses theoretical calculations to model molecular …

Determining The Structure And Function Of Type Iv-A Anti-Crisprs, Olivine Redman

All Graduate Theses and Dissertations, Fall 2023 to Present

Bacteria face a constant existential threat in the form of infection by viruses along with other forms of mobile genetic elements, such as bacteriophage and transposable elements. To survive, bacteria and other prokaryotes have evolved various immune systems to evade these would-be invaders. One such immune system is the CRISPR-Cas system, an adaptive immune system able to record the genetic signature of invading viruses in order to recognize and destroy them should they be encountered again in the future. In this thesis I present data that sheds light on the mechanism of one particular subtype of CRISPR-Cas systems: the type …

Structure Disorder And Magnetic Behavior Of An Olivine-Type Cathode Material, Hamida Hassan, Madalynn Marshall

Symposium of Student Scholars

Our research investigates the structure disorder and magnetic behavior of Li(Mn,Fe)PO₄, an olivine-type material relevant for lithium-ion battery applications. Using single-crystal neutron diffraction at Oak Ridge National Laboratory, we precisely determined Mn and Fe occupancy, revealing a 56% Fe and 44% Mn distribution at the atomic 4c site within the Pnma space group. Additionally, we observed significant lithium site vacancies (78% occupied), influencing the material's electrochemical and magnetic properties. The varying Mn/Fe ratio affected spin reorientation transitions, shifting from antiferromagnetic alignment along the a-axis to the b-axis. Our findings provide crucial insights for optimizing olivine-based cathodes, enhancing energy …

Computational Study Of The Proton Transfer In The H7o3+ Cluster, Anna James, Martina Kaledin

Symposium of Student Scholars

Proton transfer (PT) from one molecule to another is among the most studied phenomena in chemistry. PT requires the bond cleavage and the formation of a new one, AH⁺ + B -> A+ BH⁺. In protonated water clusters, such a process consists of the interconversion of hydrogen bonds. Experimentally, such a process can be observed as a significant increase of a dipole moment. However, other vibrational transitions often occur with small changes in the dipole moment while large changes in polarizability. In this work, we study the PT process in a protonated water cluster, H₇O …

Predicting Healthcare Service Quality Based On A Kalman-Optimized Bi-Lstm-Inspired Deep Learning Model, Mohammed K. Al-Khafaji, Eman S. Al-Shamery

Karbala International Journal of Modern Science

Health is one of the most important aspects of human well-being, and access to high-quality healthcare is essential for a good quality of life. Providing top-level health services at all times is crucial. However, the research in healthcare poses significant challenges due to the diversity and variations of medical practices across different hospitals. This paper aims to tackle the challenge of data missing and scattering during data collection. Then, the quality of services (QoS) offered by healthcare facilities will be analyzed and predicted from the patient's perspective. The model begins preprocessing data by data cleaning, handling missing values, and scattering …

Synthesis Of Surface Bound Ligands Through Click Chemistry For A Tethered Catalyst System Towards The Reduction Of Carbon Dioxide, Emma J. Goehner

Departmental Honors & Graduate Capstone Projects

The electrochemical reduction of carbon dioxide (CO₂) offers a promising strategy for reducing excess atmospheric CO₂ by converting it into valuable chemical products. This process can be catalyzed by transition metal complexes, particularly those with extended aromatic ligands such as terpyridines which coordinate with metals in a tridentate fashion. When tethered to an electrode, the terpyridine-metal catalyst complex allows for stable binding and reusability without the need for chemical separation to recover the catalyst. Self-assembled monolayers (SAMs) of (3-bromopropyl) phosphonic acid were formed on copper surfaces, enabling attachment of terpyridine ligands through a click reaction between a …

Understanding The Through-Space Intermolecular Interactions Of Isothiourea Catalysts In Acylation/Silylation Reactions Of Secondary Alcohols, Ziyuan Gong

Theses and Dissertations

Through space interactions, including cation-π interaction, lone pair-πinteraction, steric hinderance etc. play a central role in organocatalytic reaction. They can control the reactivity or the selectivity of an organic reaction. Previous work in our group has already shown that the chiral isothiourea compounds can catalyze the acylation as well as silylation reaction of secondary alcohol with the possible cation-πinteraction between the catalyst and substrate. However, there is lack of study to understand how the delocalization of the positive charge would affect the reaction rate and whether some unexpected inter- or intramolecular interaction could help stabilize …

Expanding Tailored Nanomaterials With Precise Spatial And Morphological Control, Mengxue Zhang

Theses and Dissertations

Multicomponent nanocomposites with precise spatial control are important for diverse fields spanning from energy conversion to optoelectronics and catalysis. Traditional methods using hydrophilic interactions alone are limited to random mixtures when multiple nanoparticle (NP) types are combined. To improve capabilities, a new strategy for polymer micelle design combining orthogonal hydrophilic (H) and fluorophobic (F) interactions to independently control two distinct NP populations was developed.

Initial research aimed at understanding F-interaction adjustments, which further enabled the switchability of FNP distribution states (dispersion vs aggregation) within polymer films through immersion annealing. Next, dual-NP assembly was examined using a diblock poly (H-b-F) where …

The Design And Optimization Of Optical Systems For The Detection And Characterization Of Phytoplankton, Caitlyn M. English

Theses and Dissertations

Phytoplankton are among the smallest organisms found in marine and freshwater ecosystems. Despite their small size, phytoplankton play a vital role in sustaining life on Earth as primary producers. Through oxygenic photosynthesis phytoplankton are also responsible for large scale carbon fixation and oxygen production. The distribution of phytoplankton in a given water resource can exhibit a high degree of variability across time and space, and this is in large part due to their varying sensitivities to environmental conditions such as resource availability and grazing by predator organisms. As such, phytoplankton community structure is widely used as an investigative tool for …

Thermodynamic Study Of Ligand Coordination On Lead Halide Perovskite Quantum Dots, Bishal Adhikari

Theses and Dissertations

Inorganic lead halide perovskite (ILHP) has been extensively studied in thin films and bulk crystals as promising materials for their photovoltaic and optoelectronic properties. These are stable enough to be prepared as colloidal quantum dots that can be dispersed, deposited and used to achieve quantum confinement; however, selection of the suitable surface passivating ligand remains challenge for long term stability of the colloidal quantum dots. Several ligand coordination chemistries used to achieve greater stability or specific functions: these can be installed at time of synthesis in some cases they can also be installed to preexisting quantum dots by ligand exchange …

Building A Framework For Analyzing Non-Linear And Multidimensional Kinetics, Mainak Dhar

Theses and Dissertations

Many materials exhibit multiple rates of molecular relaxation due to structural complexities. Standard linear and one-dimensional kinetic cannot extract all the necessary dynamic information about these systems. This dissertation contributes to an overarching scheme to develop new non-linear and multidimensional kinetic experiments to obtain this information. The studies span computation and experiments, picosecond to second timescales, and both single-molecule and pulsed-laser kinetics

Single-molecule kinetics experiments yield time series that contain information about unique structural and dynamic properties of materials. However, these time series are noisy, and data analysis is challenging. Parametric methods are computationally intensive and require strong, unverifiable assumptions …

Explorations Of Multi-Carboranyl Thiols And Phosphines, Jared Ross Riffle

Theses and Dissertations

In order to ascribe the impact of substituent groups on the bis-ortho-carborane, closo-{C2B10}-closo-{C2B10} multi-cluster system, the first sulfur-containing biscarborane derivatives were synthesized. Biscarborane dithiol, disulfide, bis(methyl)thioether, as well as multiple dithiolate salts were structurally characterized. The exceedingly long C–C bonds and shortened C–S bonds in biscarborane dithiol and its doubly deprotonated dithiolate salts are indicative of significant delocalization of electron density from the sulfur atoms into the cluster. Additionally, a new concept of ligand ambiphilicity is described where, instead of the involvement of only a single center in a ligand, this amphiphilicity relies on the redox behavior of the indirectly …

Dual Colorimetric And Fluorometric Detection Of Hydrogen Peroxide In Aqueous Samples, Nathan F. Surles, Kaitlin A. Edwards

ATU Scholars Symposium

In this project, a simple, inexpensive colorimetric and fluorometric method for determining hydrogen peroxide in aqueous samples is described. In this method, aryl boronic acid is de-protected to produce a red dye that absorbs and emits in the red/near infrared region of the electromagnetic spectrum. Upon deprotection by the hydrogen peroxide, an intramolecular charge transfer occurs between a strong phenolate donor and a TCF acceptor to produce the strong absorption and bright fluorescence. This allows naked eye detection of hydrogen peroxide within seconds in water under physiological conditions. The detection limit is impressive and falls in the sub-micromolar (µM) range. …

Computational Modeling Of Poly-Peptide Chains, Nathan F. Surles, Kaitlin A. Edwards

ATU Scholars Symposium

Investigations of the structural properties of polypeptides are essential for understanding their conformational behavior, stability, and potential biological interactions. In this study, we employed computational techniques to determine the optimized structures of two model polypeptides: tri-glycine and di-tryptophan.

Synthesis Of Organosilicon Substituted Fₓpczn For The Preparation Of Silica-Based Photo-Catalysts, Reagan E. Daly

Seton Hall University Dissertations and Theses (ETDs)

This study began with the synthesis, purification, and catalytic application of hexadeca fluoro phthalocyanine zinc (F₁₆PcZn) derivatives functionalized with organosilane consuming thiol groups. The F₁₆PcZn was synthesized by reacting tetrafluorophthalonitrile (TFPN) with zinc acetate (Zn(OAc)₂) in 1-chloronaphthalene as a solvent, under a controlled heating process at 185°C for 90 minutes. The resulting blue solid was purified via vacuum filtration and recrystallization techniques to remove residual solvents and by-products, yielding pure F₁₆PcZn. The purity of the product was assessed through UV-Vis spectroscopy, MALDI analysis, and a molar extinction coefficient was determined.

Subsequent nucleophilic substitution of the fluorine atoms on F₁₆PcZn with …

Variation Of Membrane Electrode Assembly Catalyst Layer In Unitized Regenerative Fuel Cell, Yollanda Nurcholifah, Dedi Rohendi, Edy Herianto Majlan, Nirwan Syarif, Addy Rachmat, Dwi Hawa Yulianti, Nyimas Febrika S

Journal of Electrochemistry

A unitized regenerative fuel cell (URFC) is a device that may function reversibly as either a fuel cell (FC) or water electrolysis (WE). An important component of this device is the Membrane electrode assembly (MEA). Therefore, this study aimed to compare the performance outcomes of MEA using electrodes with single and three catalyst layers. This study measured Electrochemical Surface Area (ECSA), Electrochemical Impedance Spectroscopy (EIS), X-ray Diffraction analysis (XRD), and X-ray Fluorescence (XRF). Furthermore, the round-trip efficiency (RTE) of the MEA, as well as the performance in FC and WE mode, was measured. In comparison, The ECSA values of Pt-Ru/C …

From Clusters To Frameworks: Synthesis, Engineering, And Application Of Sub-2-Nanometer Nanoclusters And Microporous Covalent Organic Frameworks, Melika E Kenari

Chemistry Theses and Dissertations

In this dissertation, we have investigated the complex interplay of atomic composition, structural modifications in covalent organic frameworks (COFs), and atomic-level designs in bimetallic chiral nanoclusters (NCs). By synthesizing COFs and bimetallic NCs, we elucidated how these elements govern their exceptional catalytic, optical, and electronic properties. Our work demonstrates that precise atomic adjustments, tailored pore engineering in COFs, and the strategic use of chiral ligands in NCs enable fine-tuned reactivity and stability. These advancements were applied to enhance photocatalytic performance, optimize iodine adsorption, and facilitate asymmetric A3 coupling reactions, laying a robust foundation for practical applications and future innovations in …

Performance Of Co2/H2O Co-Electrolysis In A Flat-Tube Solid Oxide Electrolysis Cell Stack Under Air-Free Environment, Xiao-Hui Zhong, Fei Wang, An-Qi Wu, Bei-Bei Han, Jian-Xin Wang, Wan-Bing Guan

Journal of Electrochemistry

This work investigates the transient performance and stability of CO₂/H₂O co-electrolysis in an air-free environment using a flat-tube solid oxide electrolysis cell (SOEC) stack. The results show that the transient behavior of the stack with and without blowing gas in the air electrode is almost the same. With a current density of 0.67 A·cm⁻²@750 °C, the stack operated for over 200 h under co-electrolysis conditions with no air blowing, and the voltage drop rate of the stack was approximately 0.203%/100 hours. Microstructure analysis reveals significant loss of Ni particles and formation of an insulating …