Chemistry Commons^™

A Fundamental Study Of Fatty Acid Ionic Liquids And Their Effects On Biomolecules, Achismita Dutta

Theses and Dissertations

Fatty acid ionic liquids (FAILs) are a class of ionic liquids (ILs) with relatively low toxicity and potential applications in biological systems. This study examined the interactions of tetramethylguanidinium decanoate, tetramethylguanidinium octanoate, choline decanoate, and choline octanoate with lipid membranes, proteins, and nucleic acids. Membrane leakage experiments using model lipid vesicles showed that decanoate-based FAILs produced greater membrane permeabilization than octanoate-based analogues, consistent with their higher membrane permeability. These effects were stronger for the ILs than for decanoate alone and occurred below the critical micelle concentration (CMC), suggesting that micelle formation may not be essential for membrane disruption. The ability …

Tuning Ion Mobility And Molecular Confinement In High-Performance Polymer Electrolytes For Energy Storage, Ezzeldien Yousef Muhammed Yousef

Theses and Dissertations

This research addresses the critical energy density limitations of aqueous supercapacitors, which are traditionally constrained by the narrow electrochemical stability window (ESW) of water 1.23 V. By employing two distinct molecular engineering strategies, this study developed high-performance electrolyte systems that significantly extend voltage stability and thermal resilience.

The first system, CsBr@PAM/HA, utilizes a polyacrylamide and hyaluronic acid hydrogel matrix. This system exploits the chaotropic nature of Cs⁺ ions to disrupt the aqueous hydrogen-bonding network, enhancing ionic conductivity to 104 mS cm^-1. Through systematic salt screening, CsBr was identified as the optimal electrolyte, enabling a stable 2.0 V …

Engineering Nanoelectrocatalytic Systems For Co2 And Nitrate Conversion Into Value-Added Chemicals, Abdelrahman Mohamed Abdelmohsen

Theses and Dissertations

The thesis addresses two major related environmental crises: nitrate pollution of water systems and the ever-increasing levels of atmospheric carbon dioxide. Both challenges are closely linked to anthropogenic disturbance of nitrogen and carbon cycles and require sustainable, energy efficient mitigation techniques. In this study, we investigate electrochemical conversion routes as a unified approach to convert these pollutants into value-added compounds: ammonia (NH3) via nitrate reduction (NO3-RR) and ethylene (C2H4) via carbon dioxide reduction (CO2RR). The first half of this work deals with the design and engineering of Cu-Zn alloy electrocatalysts for efficient NO3-RR. Tuning the alloy composition and surface nanostructure …

Low-Dimensional Metal Halides For Light-Emitting Diodes (Leds): Photophysical Aspects And Device Engineering, Udara Madushanka Kuruppu Kuruppu Achchige Don

Theses and Dissertations

In recent years, low-dimensional metal halides have garnered significant interest due to their exceptional optical properties. This dissertation focuses on the structural, optical, and photophysical properties of both lead-based and lead-free low-dimensional metal halides and investigates their applications in light-emitting diodes. In Chapter II, the nature of Mn2+ doping in two-dimensional (2D) lead halide perovskites is discussed. 2D perovskites show strong excitonic and dielectric confinement due to their quantum well structures. Introducing optically active Mn²⁺ dopant ions into these 2D perovskites further enhances their optical properties and promotes energy transfer from the host to the Mn²⁺ dopants, resulting in dual …

Insights Into Androgen Receptor Allosteric Modulation By P,P'-Dichlorodiphenyldichloroethylene Binding At The Binding Function-3 Site And Site-Specific Binding Function-3 Mutations, Emanuel Aggeo Flores

Theses and Dissertations

One of DDT’s metabolites, p,p’-dichlorodiphenyldichloroethylene (DDE), has been classified as an endocrine disrupting chemical (EDC) due to its ability to interfere with hormone signaling by binding to nuclear receptors (NR) such as the androgen receptor (AR).

Structurally, the AR contains a ligand-binding domain (LBD) where endogenous steroids bind. Furthermore, the LBD contains a surface binding site known as binding function-3 (BF-3), which studies suggest exerts an allosteric effect on bound DHT when small, hydrophobic molecules bind.

Here, we present a study that examines how specific BF-3 site mutations and DDE binding affect steroid stability within the LBP utilizing computational methods. …

General Chemistry Students' Perceptions Of How Various Course Resources Affect Their Learning And Exam Preparation, Jennifer Scoggin Cortez

Theses and Dissertations

The tertiary-level first-semester general chemistry course has a large range of material with different complexities that can be difficult for students to master within one semester. In the general chemistry I course under study here, students were provided with a variety of resources to help with their learning and understanding, with various components of the course, including the lecture, online textbook, Peer-Led-Team-Learning (PLTL) study sessions, and exams, having associated resources. This study aims to analyze students’ experiences with these various resources. Students were given semi-structured interviews where they talked about their experiences with the resources and provided insight into more …

Probing The Dynamic Behavior Of The Androgen Receptor In The Presence Of Heptyl And Methyl Parabens, Edgardo De Leon

Theses and Dissertations

The androgen receptor (AR) mediates physiological signaling from endogenous androgens, a function that can be disrupted by endocrine disruptors with serious reproductive and developmental consequences. Parabens, widely used preservatives, inhibit AR signaling in cell-based assays, with inhibitory potency correlating with alkyl chain length: heptylparaben exhibits stronger antagonism than methylparaben, which shows no effect. We hypothesize this differential potency arises from allosteric modulation at the AR Binding Function 3 (BF-3) site, altering dihydrotestosterone (DHT) binding dynamics. Docking calculations using antagonist-bound AR crystal structures, followed by molecular dynamics simulations, show that methylparaben fails to remain bound at BF-3, whereas heptylparaben maintains stable …

Structure–Property Engineering Of Sn-Based Hybrid Perovskites Via Bulky Organic Cation Incorporation: From 3d To 2d Architectures, Kevin Alejandro

Theses and Dissertations

This thesis investigates tin-based hybrid organic/inorganic perovskites (HOIPs) as a lead-free alternative to silicon solar cells. To manipulate optoelectronic and efficiency of the semiconductors, methylammonium was substituted with bulky propylammonium and tetrabutylammonium cations to induce quasi-2D/3D Ruddlesden-Popper phases. X-Ray Diffraction confirmed 2D layered phases in propylammonium hybrids (5-15%), while tetrabutylammonium hybrids faced steric limits, triggering vacancy ordered perovskite phases at 1% concentration. Optical analysis showed a bandgap narrowing from 1.30 eV to 1.26 eV with increased substitution. Although photovoltaic performance generally declined, the 10% propylammonium hybrid achieved the highest fill factor of ~0.79, indicating superior internal charge transport. This work …

Degradation And Metabolic Analysis Of Synthesized Quorum-Sensing Signals By The Model Eukaryote Chlamydomonas Reinhardtii, Adam Josef Bach

Theses and Dissertations

Bacterial organisms can “talk” with one another on a colony-wide scale using a communication system known as quorum-sensing (QS) via chemical signals. These signals are produced at a basal rate throughout the life of the bacteria and are classified as autoinducers, which diffuse across the cell membrane. Once the critical concentration is reached, they begin to diffuse back into the cell and initiate a phenotypic change. As these signals exist outside the membrane of their producer, they are also accessible to other organisms. It has already been noted that some plant species uptake these compounds through their roots and break …

An Efficient Approximation To The Vibrational Coupled Cluster Method For Large Molecules, Nivedhitha P Ms

Theses and Dissertations

The Watson Hamiltonian is a widely used model for describing anharmonic vibrational motion in polyatomic molecules. It expresses the kinetic energy in separable dimensionless normal coordinates and represents the potential energy as a Taylor series expansion around the equilibrium geometry, usually up to the quartic approximation. Several computational methods have been developed to solve the corresponding vibrational Schrödinger equation for predicting infrared (IR), Raman, and vibrational circular dichroism (VCD) spectra. These include the Vibrational Self-Consistent Field (VSCF) method, Vibrational Configuration Interaction (VCI) and its approximations, and Vibrational Second-Order Perturbation Theory (VPT2), each providing different balances between computational cost and accuracy. …

Synthesis And Characterization Of Transition Metal Carbide (Max) And Mxene Nanoflakes For Energy Storage And [email protected], Srikanth Ragunath B Mr

Theses and Dissertations

Rapid growth in population and industrialization created a huge demand for superior energy storage devices. Thus, the researchers are in constant search of developing exotic materials towards energy harvesting and storage devices. Batteries, supercapacitors, and fuel cells received a great attention to meet the global demand for energy storage. Among them, supercapacitors are widely preferred as energy storage devices due to higher power density, longer cycle life, and fast charging. The performance of the supercapacitors highly depends on the choice of electrode materials and electrolyte.

Recently, “MXenes”  a new class of layered a new class of layered a new …

Development Of Salinomycin Analogs As Potential Anti-Cancer Agents, Pavan Goud Juluri

Theses and Dissertations

Salinomycin, a poly-ionophore antibiotic originally isolated from Streptomyces albus, exhibits antimicrobial activity against Gram-positive bacteria. Over the years Salinomycin has been studied in the effects it has on cancer, specifically cancer stem cells. Poly(ADP-ribose) polymerase (PARP) is an enzyme involved in DNA repair. Inhibiting PARP has been explored as a strategy in cancer treatment, particularly in cancers with defective DNA repair mechanisms, such as those with BRCA mutations. The benzo-thiazoles, and -imidazoles are identified as inhibitor scaffolds, which compete with nicotinamide in the binding pocket of human poly- and mono-ADP-ribosylating enzymes. Benzothiazole, and benzimidazole based compounds particularly with modification at …

Structural Characterization Of Peptide Nanoaggregates At Varying Concentrations And Their Impact On Cellular Responses, Malika Rozmetova

Theses and Dissertations

Peptide nano-assemblies can regulate cellular pathways in a structure-dependent manner. Here, we show that the enzyme-responsive peptide NapFFK(NBD)Yp forms distinct nanoscale assemblies at different concentrations, triggering differential ER stress and extracellular vesicle release in MDA-MB231 cells. These results highlight the importance of supramolecular organization in peptide–cell interactions.

Absolute Quantification And Identification Of Rna From Rna-Lipid Nanoparticles Using High Resolution Mass Spectrometry, Jason C. Funderburk

Theses and Dissertations

RNA therapeutics are a rising drug category with potential use for a range of conditions encompassing infectious diseases to therapies for cancer, diseases, and genetic disorders. RNA-lipid nanoparticles (RNA-LNPs) are the prominent delivery method for these therapeutics approved products include mRNA vaccines and polyneuropathy treatments. The emergency use authorizations and orphan drug status of current RNA-LNP drugs has allowed approval without finalization of the regulatory analytical procedures for quality monitoring. The objective of the study was to develop an LC-MS assay to simultaneously measure identity and concentration of two therapeutically relevant intact RNA constructs extracted from RNA-LNPs to enhance quality …

De Novo Protein Binding To Zinc Oxide Through Biomineralization Pathways, Jean-Mark A. Francis

Theses and Dissertations

De novo proteins are structurally distinct from proteins found in nature and thus capable of having their amino acid sequence modified to accomplish tasks such as increasing protein-nanoparticle binding without unfolding or decomposing. Zinc Oxide nanoparticles are functionally distinct from their bulk counterparts and are widely used as semiconductors in a variety of fields such as medicine and agriculture. With demand for these nanoparticles increasing, environmentally sustainable methods of Zinc Oxide nanoparticle synthesis are being investigated as an eco-friendly alternative to currently utilized but environmentally hazardous chemical and physical techniques. This research investigates the binding characteristics between Zinc Oxide nanoparticles …

Inductively Heated Platinum Electrodes, Jayamini Madumali Mudugamuwa Hewage

Theses and Dissertations

This dissertation presents the fabrication and application of a 150 micrometer platinum microelectrode for induction heating, with a copper coil generating the electromagnetic field and the heating process controlled using pulse width modulation technique (PWM) to regulate the duty cycle of a high-frequency signal. Electrochemical characterization, including resonance frequency determination, peak-to-peak potential optimization, and scan rate variation, is conducted using a 5 mM [Ru(NH3)6]2+/3+ solution in 0.1 M KNO3 to calibrate current variations with changing duty cycles, while the temperature increase (delta T) is estimated using the Seebeck coefficient of [Ru(NH3)6]2+/3+. The study further explores the application of induction heating …

Rapid Kinetic Fluorogenic Quantification Of Malondialdehyde In Ground Beef, Keshav Raj Bhandari

Theses and Dissertations

Presented herein is rapid kinetic fluorogenic method to quantify malondialdehyde (MDA) in ground beef, utilizing 2-thiobarbituric acid (TBA) as the fluorogenic probe. This assay significantly shortens the total analysis time, from sample preparation to data acquisition, to just six minutes presenting a major advancement over traditional methods that typically require two hours and multiple instruments. The assay’s robustness against matrix interferences was validated using sample volume variation and standard addition calibration methods. Additionally, the effects of ambient exposure to air, washing, and cooking on MDA content in raw ground beef were quantified. While both ambient exposure to air and cooking …

Development Of Natural Product Analogs As Therapeutic Agents, Jacob Mara

Theses and Dissertations

Cancer stem cells (CSC) are cancer cells in a tumor mass that may self-renew and develop into various cell types, resulting in a heterogeneous tumor. CSCs have been shown to have a role in many facets of cancer formation, including tumor genesis, proliferation, and metastatic activity. They are also implicated in chemotherapeutic treatment resistance and the recurrence of some malignancies. Based on these capacities, CSCs have been identified as the next target for cancer therapy and control. Salinomycin's potential for therapeutic use based on ongoing research, as well as the synthesis of its derivatives and their biological activity, will also …

Improved Extraction And Detection Of Disinfection Byproducts, Impacts Of Wildland-Urban Interface Wildfires On Drinking Water, And Change In Disinfection Byproducts Over Time In Chlorinated Vs. Chloraminated Distribution Systems, Patrick Thomas Justen

Theses and Dissertations

Drinking water disinfection is critical to prevent the occurrence of waterborne pathogens in drinking water. However, disinfection causes the unintended formation of disinfection byproducts (DBPs) through the reaction of disinfectants (e.g., chlorine, chloramine) with natural organic matter (NOM), algal matter, or anthropogenic pollutants present in source waters. Exposure to DBPs is associated with increased bladder cancer, colorectal cancer, miscarriage, and birth defects. The U.S. EPA currently regulates eleven DBPs in drinking water—four trihalomethanes, five haloacetic acids, bromate, and chlorite. However, research shows that DBP related toxicity in drinking water is driven mainly by other, non-regulated DBPs, particularly iodinated DBPs and …

Synthesis And Characterization Of Lanthanide Extended Structures And Their Novel Transuranic Analogues, Hunter Bernard Tisdale

Theses and Dissertations

The United States owns a substantial amount of radioactive waste as a result of decades of research, weapons manufacturing, and nuclear energy production. As nuclear energy and research continue to add to our stockpiles of waste, the issue of remediating this waste becomes more pressing. Many of the radioactive constituents of this waste, such as the transuranic (Z > 92) elements, will give off radioactivity at harmful levels for millennia. Thus, a robust method of storing this waste is paramount to ensuring public safety. Currently, nuclear waste is being processed by vitrifying it in borosilicate glass. However, this method has shortcomings …

Molecular Architecture And Mechanical Response In Polymeric Materials: Thin Films, Linear-Ring Elastomers, And Lignin, Siteng Zhang

Theses and Dissertations

Understanding the mechanical behavior of polymeric materials is critical to advancing modern technologies, from flexible electronics to sustainable adhesives. This dissertation investigates the micromechanics of polymer thin films, dual-network elastomers, and bio-based lignin materials, with an emphasis on deformation mechanisms, network topology, and mechanical properties. The work combines principles of polymer physics with materials science to uncover structure–property relationships that inform polymer design. This dissertation primarily uses coarse-grained and atomistic molecular dynamics simulations to investigate molecular-scale behavior beyond experimental reach. Through these methods, critical insights are gained into how entanglement, topology, and chain architecture govern bulk material performance. The first …

Validation And Proposed Expansion Of The Data-Driven D Region Model, Kevin M. Watson

Theses and Dissertations

Predicting ionosphere effects on radio wave propagation is critical for communications and over-the-horizon radar systems. The D region is challenging to model for several reasons, one of which is chemical complexity. Ion density changes during sunrise/sunset introduce substantial uncertainty in electron density profiles (EDPs). The Data Driven D Region (D3R) model solves electron densities through an ion chemistry model and assimilates relevant space weather inputs. This study evaluates D3R against the Faraday International Reference Ionosphere (FIRI) and measurements using Very Low Frequency (VLF) propagation paths. Space weather event impacts on D3R EDPs are evaluated during the disturbed period from 8-12 …

Oxidation Resistance And Osmotic Energy Harvesting Applications Of Reduced Graphene Oxide Forward Osmosis Membranes, Michael Appiah-Kubi

Theses and Dissertations

Reduced graphene oxide (RGO) forward osmosis (FO) membranes have emerged as promising candidates for efficient wastewater management and osmotic energy harvesting, due to their enhanced chemical stability and superior FO performance for low-energy waste brine treatments, such as volume reduction of oxidative chromium brine for cost-effective disposal. This dissertation first examines the oxidation resistance of RGO forward osmosis membranes against chromate Cr (VI). Our findings reveal that both the water flux and the reverse salt flux of RGO membranes are suppressed, accompanying an enhanced reverse flux selectivity after exposure to an acidic medium of Cr (VI) (pH 2.0-7.0). Meanwhile, the …

Design And Investigation Of Triarylamine Functionalized Luminophores For Multi-Functional And Stimuli-Responsive Applications, Sasikala R

Theses and Dissertations

Organic solid-state fluorescent materials have garnered attention over many decades in virtue of their contribution in the development of LED devices and biomedical applications. Nevertheless, the potential of fluorescent molecules in device applications was underused due to aggregation-caused quenching (ACQ) effect. The ACQ effect commonly quenches the organic molecules fluorescence intensity in the aggregated or condensed state, which can significantly influence their performance in practical applications.

The organic polyaromatic fluorophores exhibit strong fluorescence in the solution state. After culmination of years of work, Prof. Tang’s research group discovered a new phenomenon of aggregation-induced emission (AIE) in the fluorescence molecules constructed …

Synthesis And Evaluation Of Novobiocin Analogues As Potential Inhibitors Of Polymerase Theta Polθ In Dna Damage And Repair, Mohammed Essam Albuhluli

Theses and Dissertations

Killing tumors while leaving normal cells unharmed is the goal of precision cancer therapy, a challenging feat that is enabled by targeting tumor-specific vulnerabilities [1]. Targeting Polθ potentiates PARP inhibitors (PARPi) in specifically killing homology-directed repair (HDR)-deficient tumor cells and re-sensitize PARPi resistant tumor cells [1]. The induced essentiality between Polθ and HDR-deficiency underscores the value of Polθ as a therapeutic target in the context of tumors with HDR genetic mutations [1]. The helicase-like domain (HLD) is a super family 2 (SF2)-type domain with DNA-dependent ATPase activity [1]. We previously discovered that the antibiotic NVB acts as an inhibitor of …

Synthesis Of Inorganic Actinide Compounds With Neptunium, Plutonium, And Americium, Travis Kelly Deason

Theses and Dissertations

There is a rush of countries around the world making the switch to greener energy sources. Nuclear energy power plants are an integral part of the shift from fossil fuels, but there are concerns over the best way to handle nuclear waste. Most of the nuclear waste is currently disposed of by incorporating the waste into a glass form through vitrification, but research into alternative waste forms, such as promising crystalline materials, could provide a more robust method of containment. Research on actinide materials is lacking due to the dangers of working with radioactive material and there are few labs …

Structure-Activity Relationships Of Isothiourea And Silicon Phthalocyanine Catalysts, Christian J. Harrison

Theses and Dissertations

Efficient organic synthesis often relies on improving catalyst designs and investigating reaction mechanisms to accomplish feats such as high stereoselectivity, low catalyst loadings, and performing sustainable chemistry. Within the field of organocatalysis, intermolecular interactions between a catalyst and a substrate are a large contributing factor to the control of a reaction, including rate and selectivity. Investigating mechanisms can provide information on the type of intermolecular interactions occurring in the reaction, aiding future reaction and catalyst development. This dissertation will explore two recent projects and how probing intermolecular interactions through simple modifications provides information useful for new catalyst designs and properties. …

Electrocatalytic Degradation Of Methylene Blue Using Graphene Oxide, Antimony Oxide, And Graphene Oxide-Supported Antimony Oxide Ink-Based Electrodes, Maria Irene Myers Armas

Theses and Dissertations

This study investigates the electrocatalytic degradation of methylene blue (MB) using copper mesh electrodes coated with graphene oxide (GO), antimony oxide (Sb₂O₃), and their composite (GO/Sb₂O₃). These materials were evaluated across a pH range of 2 to 8 using sodium sulfate as the supporting electrolyte. UV-Vis spectroscopy at 665 nm confirmed dye degradation, with removal efficiencies reaching up to 95% at pH 2. However, degradation decreased at higher pH, with 40 – 60% removal at pH 8, depending on the electrode. Kinetic analyses revealed optimum performance under acidic conditions. GO/Sb₂O₃ electrodes demonstrated the most consistent and effective performance across all …

Quantifying Biomass Burning Impacts On Soil Nox Emissions And Reactive Nitrogen Cycling, Olivia Rae Steinbeck

Theses and Dissertations

Nitrogen oxides (NOx = NO + NO₂) are trace gases that play a critical role in the atmosphere by influencing air quality, oxidation chemistry, and the deposition of fixed nitrogen. Historically, NOx emissions have been primarily linked to anthropogenic sources such as fossil fuel combustion, industrial activities, and agriculture. However, as successful legislation has significantly reduced these emissions, the relative importance of natural NOx sources has become an increasing concern. Soil NOx emissions are of particular interest due to their strong temperature dependence and their connection to global climate change. Rising global temperatures are expected to accelerate soil NOx emissions …

Quinone-Mediated Extracellular Electron Transfer In Escherichia Coli During Glucose Oxidation Metabolism, Megan Danielle Whisonant

Theses and Dissertations

The growing global demand for energy, ongoing reliance on fossil fuels, and increasing water pollution from industrial and anthropogenic sources present significant environmental challenges. In response to these issues, renewable and sustainable energy sources offer substantial potential for reducing dependence on fossil fuels and ensuring access to clean water. Microbial electrochemical systems (MESs) have emerged as promising, eco-friendly solutions for energy-efficient wastewater treatment and bioremediation. A key challenge in MESs development is facilitating effective electron transfer between microorganisms and electrode surfaces. The first chapter of this thesis discusses the fundamentals of MES types, explains mechanisms of extracellular electron transfer, and …