Digital Commons Network^™

Electrodeposition Parameters Dramatically Influence The Morphology, Stability, And Performance Of N-Si/Pt Light-Addressable Electrochemical Sensors, Jocelyn B. Hernandez, Zackary D. Epright, Irina M. Terrero Rodríguez, Glen D. O'Neil

Department of Chemistry and Biochemistry Faculty Scholarship and Creative Works

Light addressable electrochemical (LAE) sensors have seen great utility in the past several years because they enable multiple localized electrochemical measurements to be performed on a single macroscopic electrode, opening up applications in imaging, biosensing, surface patterning, and multiplexing. In this study, we investigated the effects of electrodeposition on the formation of LAE sensors formed between n-Si and electrodeposited Pt. We prepared sensors by electrodepositing Pt onto freshly-etched n-Si under a variety of conditions, varying the Pt precursor concentration, electrodeposition time, supporting electrolyte, and potential waveform. We characterized the sensors using a combination of atomic force microscopy, electrochemical impedance spectroscopy, …

Stereochemical Engineering Yields A Multifunctional Peptide Macrocycle Inhibitor Of Akt2 By Fine-Tuning Macrocycle-Cell Membrane Interactions, Arundhati Nag, Amirhossein Mafi, Samir Das, Mary Beth Yu, Belen Alvarez-Villalonga, Soo-Kyung Kim, Yapeng Su, William A. Goddard, James R. Heath

Chemistry

Macrocycle peptides are promising constructs for imaging and inhibiting extracellular, and cell membrane proteins, but their use for targeting intracellular proteins is typically limited by poor cell penetration. We report the development of a cell-penetrant high-affinity peptide ligand targeted to the phosphorylated Ser474 epitope of the (active) Akt2 kinase. This peptide can function as an allosteric inhibitor, an immunoprecipitation reagent, and a live cell immunohistochemical staining reagent. Two cell penetrant stereoisomers were prepared and shown to exhibit similar target binding affinities and hydrophobic character but 2-3-fold different rates of cell penetration. Experimental and computational studies resolved that the ligands’ difference …

Ru(Ii) Polypyridyl Photosensitizers For Phototherapy, Houston Cole

Chemistry & Biochemistry Dissertations - Archive

This dissertation describes the design, synthesis, and photobiological characterization of key target molecules that modify the 1) length of the IP-nT “PDT” ligand, 2) electronic nature of the bipyridine or phenanthroline type ancillary ligands, and 3) chirality of the coordination complex. The targets and subsequent studies will test the hypothesis that molecules with low-lying and long-lived 3ILCT states are responsible for this unusually high photocytotoxic potency and seeks to further understand what structural features (aside from the IP-nT ligand) lead to more favorable photobiological properties.

Mechanical Properties Of Natural Osmia Lignaria Silk And Recombinant Expression Of The Silk Proteins, Jackson Morley

Undergraduate Honors Capstone Projects

The use of petroleum-based plastic and the subsequent waste has led researchers to explore alternatives in the form of biopolymers. Spider silk and hagfish intermediate filaments show the potential to be advantageously utilized in textile and biomedical industries. Bee silk is a sparsely studied biopolymer that has shown potential to be added to these other impressive biopolymers. Osmia lignaria, is a solitary bee native to the western United States. Silk from these bees can be isolated while the larvae are spinning their silk. The silk from these bees has been mechanically tested for strength, stress, strain, and elasticity. Cocoon …

Synthesis And Characterization Of Pyrazine-Based Prodrugs: A Novel Approach To Combat Multi-Drug Resistant Tuberculosis, Charles Chambers

Chemistry & Biochemistry Theses - Archive

Synthesis and Characterization of Pyrazine-Based Prodrugs: A Novel Approach to Combat Multi-Drug Resistant Tuberculosis Charles Cole Chambers The University of Texas – Arlington, 2023 Supervising Professor: Dr. Joseph Buonomo. The work described in this thesis investigates the development and characterization of a novel prodrug designed to combat multi-drug resistant tuberculosis (MDR-TB), a significant and growing global health challenge. Central to this study is the synthesis of a pyrazine-based prodrug, which innovatively utilizes bicyclic orthoester (BOE) moieties to improve the therapeutic efficacy and safety profile of this tuberculosis treatment. At the core of this research project is the strategic design of …

Computation-Assisted Molecular Discovery For Biomedical Applications: Seeking Small Molecules And Dna Sequences With High Affinity Target Binding, Payam Kelich

Open Access Theses & Dissertations

Binding affinity between two molecules is an essential property in drug and sensor discovery. Several computational and experimental methods exist to find molecules with high binding affinities to desired target molecules. These methods are often complementary, where fast computational methods can be used for the initial screening of molecules, and experimental methods can then screen and determine the molecules of interest and sometimes define the structures of bound complexes. After these steps, computational methods, like molecular dynamics (MD) simulations, can provide detailed insights into atomic interactions and binding, and machine learning approaches can analyze experiment-derived data to discern patterns and …

Niobate Nanosheet Catalysts For Cationic Dye Intercalation And Solar-Driven Water Photolysis, Cassandra Idona Monárrez-Grendahl

Open Access Theses & Dissertations

With the goal of creating efficient visible light photocatalysts for water photolysis, in this work we are exploring the synthesis of new porous oxide materials derived from potassium triniobate (KNb3O8) and titanium niobium oxide (KTiNbO5), which are layered wide band gap semiconductors. Generating hydrogen via direct water photolysis holds promise as a way to lower the cost of hydrogen gas production so it can be used as a renewable and clean alternative fuel. My group has demonstrated that layered semiconductor materials have the potential to enable the synthesis of new types of photocatalyst composites with customizable characteristics. In this work, …

Nanoparticles And The Environment: Biopolymer Grafted Cellulose And Screen-Printed Carbon Nanotube Composites, Dominique Henry Porcincula

Master's Theses

A host of environmental issues will define the state of the environment in the 21^st century, with plastic pollution and water shortages among them. While solutions to these problems require large-scale, multipronged solutions, one way we can address them is through material innovation and the use of nanoparticles.

In the first project, we address the issue of plastic pollution by creating nanocomposites of biodegradable polymers (PLA and PCL) with cellulose nanofibrils. Here, PLA and PCL are grafted from the surface of cellulose nanofibrils via ring-opening polymerization of cyclic ester monomers. Polymer-grafted cellulose (PGC) is characterized with structural analysis, solubility …

Analysis Of Triton Cg 110 Foaming Characteristics For Use As A Potential Fire Suppressant, Addison Cobb, Jeremy Cho

Undergraduate Research Symposium Lightning Talks

Background: Per-FluoroAlkyls (PFAs) are incredibly stable molecules which do not biodegrade. These chemicals have been linked with a series of health issues and environmental problems.

Problem: PFAs have been identified in most drinking water supplies in the United States. Large Amounts of this is due to Aqueous Fire-Fighting Foams (AFFF’s), which contain PFAs, seeping into the groundwater supply.

Solution: While little can be done about PFAs currently in groundwater supplies, replacing PFA-based AFFFs with newer Eco-AFFFs can halt AFFF contamination, and maintain firefighting suppression.

Applications Of Diels-Alder Cycloadditions And Transition Metals As Catalysts To Recent Total Syntheses, Alexander H.C. Evans

Legacy Theses & Dissertations (2009 - 2024)

This thesis examines the recent advances in the applications of Diels-Alder cycloaddition reaction and Suzuki-Miyaura coupling to total syntheses of antibiotic and anti-cancer drugs. Attention is also given to intramolecular Diels-Alder cycloadditions and the use of Kinetic vs. Thermodynamic conditions. The results of the Diels-Alder cycloadditions that are discussed oftentimes result in high stereospecificity, regioselectivity, and stereoselectivity. The applications of Suzuki-Miyaura coupling and transition metal catalysts to total syntheses problems are also discussed along a similar narrative. Attention is given specifically to the use of several different gold catalysts as well as Grubb’s Catalyst. The use of the Diels-Alder cycloaddition …

Solubility, Reactivity And Diffusion In Polymeric Bilayer Thin Films, Jacob Sitterly

Legacy Theses & Dissertations (2009 - 2024)

Microelectronics manufacturing of modern devices has required the use of polymer photoresists in several essential steps. The traditional limitation in device capability has been dependent on the minimum feature size attainable by the wavelength of light and materials used in photolithography. In this thesis the study of polymer thin films in single and bilayer stacks is described. Three scientific concepts are fundamental to this study: (1) the diffusion and (2) reaction of acid and small molecules that change polymer (3) solubility. In this thesis, two chemical systems are designed and used to study these three scientific concepts.

The Effects Of Aggregation Of Tetrafluoro(Trifluoromethyl-Λ6-Sulfanyl) Ethanes On The Secondary Structure Stabilization Of Melittin: A Molecular Dynamics Simulation Study, Samadrita Biswas

Legacy Theses & Dissertations (2009 - 2024)

Introduction of novel tetrafluoro(trifluoromethyl-λ6-sulfanyl) (CF3SF4) functional group has garnered substantial interest because of its increased hydrophobicity. This super fluorinated group attributed to increased lipophilicity, decreased heat of vaporization, and lowered dielectric constants. The highly electronegative nature of this group can profoundly influence the reactivity of compounds containing the CF3SF4 moiety. The hypervalency associated with this new group presents an exciting platform to explore the fundamental understanding of molecular interactions, reactivity patterns, and electronic behaviors. This dissertation investigates the molecular properties and behaviors of tetrafluoro(trifluoromethyl-λ6-sulfanyl) ethanes (CF3SF4-ethanes), with a specific emphasis on 2-tetrafluoro(trifluoromethyl)-λ6-sulfanylethan-1-ol (CF3SF4-ethanol) and 2-tetrafluoro(trifluoromethyl)-λ6-sulfanylethanamine (CF3SF4-ethanamine). Utilizing ab initio calculations …

Photosensitized Chemically Amplified Resist (Pscar) For Extreme Ultraviolet Lithography (Euvl), Israt Hossain

Legacy Theses & Dissertations (2009 - 2024)

As Deep Ultraviolet (DUV) Photolithography has hit the limit in further shrinking semiconductor devices' critical dimension (CD) down to below 10 nm, using Extreme Ultraviolet (EUV) 13.5 nm wavelength is under intense development. EUV has higher resolution (R) as a consequence of the shorter wavelength, but EUV sources have much lower light intensity than DUV light sources, leading to sensitivity challenges. While light source intensity and photoresist sensitivity (S) have a complementary relationship, and high intensity EUV light source development only progresses slowly, this paper discusses other novel approaches to improve photoresist sensitivity with low intensity EUV light. Photosensitization chemistry …

Planar, Twisted, And Macrocyclic Polyarenes: Structures, Reduction Limits, And Reactivity, Matthew John Pennachio

Legacy Theses & Dissertations (2009 - 2024)

Molecular nanocarbons, which can be considered as fragments of fullerenes, carbon nanotubes, or graphene have invigorated the rapid development of carbon chemistry at the nanoscale in recent decades. Not only do molecular nanocarbons possess extraordinary chemical and physical properties, but they also exhibit such unique features as controllable and scalable molecular compositions, atomically uniform precision, and good stability. The advance of nanocarbon chemistry give rise to unique applications such as electron transfer, semiconductors, superconductors, and lithium-ion batteries. However, an in-depth understanding of controlled doping, charge transfer effects, and structure–property correlations has been limited in nanocarbon chemistry due to the lack …

Publication Of Undergraduate Experiments, Development Of Additional X-Ray Crystallography Experiments, And Proof-Of-Concept Cyclopropanation Reactions, Alain Beauparlant

Electronic Theses and Dissertations

Single crystal X-ray crystallography instructional materials were developed using a variety of compounds including sugar, Epsom salt, pyrite, copper(II) acetate, and rhodium(II) acetate. Rhodium(II) acetate was reacted with a variety of functionalized benzonitriles, and when crystals were obtained, characterized using single crystal X-ray crystallography. Rhodium(II) acetate with adducts of 4-nitrobenzonitrile and 4-(dimethylamino)benzonitrile were also characterized using proton NMR spectroscopy and Fourier Transform Infrared Spectroscopy. Rhodium(II) acetate with adducts of 4-(dimethylamino)benzonitrile was used as a catalyst in a proof-ofconcept reaction to determine if it acts as a catalyst in cyclopropanation reactions. Further, the new rhodium(II) acetate dinitrile compounds were investigated to …

Computational Quantum Chemistry Studies Of The Stabilities Of Radical Adducts Formed During The Oxidation Of Melatonin Derivatives, James Horne

Electronic Theses and Dissertations

Melatonin is a natural antioxidant that has been investigated for properties as a potential spin trap to identify short-lived free radicals. Computational quantum chemistry studies have been performed for the oxidation of melatonin to N¹-acetyl-N²-formyl-5-methoxykynuramine. This research focused on modification of melatonin into derivatives and analyzing the change in total molecular energy from melatonin to its oxidation product, as well as the corresponding derivatives. Each of the molecular geometries were optimized at the DFT/B3LYP/6-31G(d), DFT/B3LYP/cc-pVXZ (X = D, T), HF/6-31G(d), HF/cc-PVXZ (X = D, T), MP2/6-31G(d), and MP2/cc-PVXZ (X = D, T) levels of theory. …

Synthesis Of Bacterial Glycerophospholipids For Biomembrane Model Studies: A Means To Advanced Biofuels, Felix Adulley

Electronic Theses and Dissertations

To reduce reliance on fossil fuels, sustainable biofuels are being pursued, especially advanced biofuels like 1-butanol that have higher energy content and greater compatibility with existing infrastructure than ethanol. A persistent challenge is the yield-limiting toxicity of biofuels and process solvents, such as tetrahydrofuran, to the microbes that ferment biomass into biofuel. The cell membrane is a focal point of toxicity, and understanding how it interacts with fuels and solvents is key to improving yield. Phospholipid bilayers are the core of biomembranes, and model biomembranes of defined composition provide the ideal platform for biophysical studies. To this end, glycerophospholipids characteristic …

Stress-Sensing In Flexible Epoxy Adhesives, Christine Rukeyser

Honors Theses

In mechanochemistry, mechanical force causes a chemical change using small molecules, called mechanophores, by covalently connecting them into polymer materials. Stress-sensing mechanophores give a visual signal of mechanical force on the molecular level within a material. To our knowledge, stress-sensing mechanophores have never been incorporated into a commercially available epoxy kit. In this work, the characterization of two 3MTM Scotch-Weld TM Epoxy Adhesive kits: DP100 Plus Clear and DP190 Translucent have been completed through FT-IR Spectroscopy. The addition of the mechanophore spiropyran to the 3M kits will be discussed; as well as preparation and characterization of three dimerized anthracene derivatives. …

Characterization Of Interlayer Laser Shock Peening During Fused Filament Fabrication Of Polylactic Acid (Pla), Fabien Denise

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

The field of additive manufacturing (AM) has gained a significant amount of popularity due to the increasing need for more sustainable manufacturing techniques and the adaptive development of complex product geometries. The problem is that AM parts routinely exhibit flaws or weaknesses that affect functionality or performance. Over the years, surface treatments have been developed to compensate certain flaws or weaknesses in manufactured products. Combining surface treatments with the modularity of additive manufacturing could lead to more adaptable and creative improvements of product functions in the future. The current work evaluates the feasibility of pursuing a new research axis in …

Studies Toward A Total Synthesis Of The Pyrrole-Imidazole Alkaloid Palau'amine And Computationally Assisted Stereochemical Elucidation, Brandon Fulton

Chemistry & Biochemistry Dissertations - Archive

This thesis documents progress toward a total synthesis of the marine natural product palau'amine, a stereochemically dense hexacyclic pyrrole-imidazole alkaloid with pharmaceutically relevant anticancer, antifungal, and antibacterial activity. Also described herein are several miscellaneous synthesis projects and the application of computational NMR as an aid for solving structure elucidation problems. Chapter 1 is a continuation of our lab’s prior work utilizing vinylimidazoles in cycloaddition reactions to gain rapid access to scaffolds resembling dimeric pyrrole-imidazole alkaloids such as ageliferin or palau’amine. Mechanistic aspects of these cycloadditions for both inter- and intramolecular cases were probed via time-course NMR experiments and computational studies, …

Ionically Crosslinked Cellulose Nanocrystals By Metal Nitrates For The Preparation Of Stable Emulsions With Tunable Interface Properties, Joseph Batta-Mpouma, Gurshagan Kandhola, Jin-Woo Kim

Materials Science and Engineering Faculty Publications and Presentations

Biologically extracted cellulose nanocrystals (CNCs) are rod-like and amphiphilic materials with surface-exposed (hydrophilic sites) and hidden (hydrophobic sites) hydroxyl groups. These physicochemical characteristics make CNCs suitable for use as emulsifying agents to stabilize emulsions. Stable oil-in-water emulsions, using sulfated (i.e., – SO₃−) CNCs that were ionically crosslinked with alkaline-earth (i.e., Mg ²⁺) or transition-d-block (i.e., Zn ²⁺) metal cations, were developed without the use of any synthetic surfactants or prior functionalization of pure CNCs with hydrophobic molecules. Various emulsion surface properties such as interfacial tension, surface charge, surface chemistry, as well as rheology were characterized. Ionically …

Deficiency Of Acute-Phase Serum Amyloid A Exacerbates Sepsis-Induced Mortality And Lung Injury In Mice, Ailing Ji, Andrea C. Trumbauer, Victoria P. Noffsinger, Luke W. Meredith, Brittany Dong, Qian Wang, Ling Guo, Xiangan Li, Frederick C. De Beer, Nancy R. Webb, Lisa R. Tannock, Marlene E. Starr, Christopher M. Waters, Preetha Shridas

Saha Cardiovascular Research Center Faculty Publications

Serum amyloid A (SAA) is a family of proteins, the plasma levels of which may increase >1000-fold in acute inflammatory states. We investigated the role of SAA in sepsis using mice deficient in all three acute-phase SAA isoforms (SAA-TKO). SAA deficiency significantly increased mortality rates in the three experimental sepsis mouse models: cecal ligation and puncture (CLP), cecal slurry (CS) injection, and lipopolysaccharide (LPS) treatments. SAA-TKO mice had exacerbated lung pathology compared to wild-type (WT) mice after CLP. A bulk RNA sequencing performed on lung tissues excised 24 h after CLP indicated significant enrichment in the expression of genes associated …

Development Of A Methodology For The Quantification Of Reaerosolization Of A Biological Contaminate Surrogate Particle From A Military Uniform Fabric, George Cooksey, Jeremy M. Slagley, Casey W. Cooper, Douglas Lewis, Alisha Helm

Faculty Publications

In a mass casualty medical evacuation after a bioaerosol (BA) dispersal event, a decontamination (DC) method is needed that can both decontaminate and prevent biological particle (BP) re-aerosolization (RA) of contaminated clothes. However, neither the efficacy of current DC methods nor the risk of BP RA is greatly explored in the existing literature. The goals of this study were to develop a repeatable method to quantify the RA of a biological contaminant off military uniform fabric swatches and to test the efficacy of one DC protocol (high-volume, low-pressure water) using 1 µm polystyrene latex (PSL) spheres as a surrogate. A …

Advanced Progress In Metal Halide Perovskite Solar Cells: A Review, Judy Fan

Physics Faculty Research

Organic and inorganic hybrid perovskite solar cells (PSCs) have attracted intense attention in the past decades due to their fantastic performance in stability, durability, rapid processing, and high efficiency competitive to Si-based counterparts. The lab-fabricated solar cells based on organolead halide perovskites have reached a record efficiency of 26.1 %, which implies that halide perovskite materials may open a new paradigm for future solar energy innovation. Organometal/inorganic halide perovskites take advantage of tunable bandgaps, engineerable composites/interfaces, and solution-processible methods that render easy integrations of subcells to form tandem and multijunction modules with higher efficiencies potentially beyond the Shockley-Queisser (SQ) limit. …

Enhancing Urban Water Quality Through Biological-Chemical Treatment: Aquatic Macroinvertebrate Community And Temporal Chlorophyll-A Response, Matthew Chaffee

Department of Agricultural and Biological Systems Engineering: Dissertations, Theses, and Student Research

With a growing human population, urbanization is impeding a plethora of natural waterways. Of these, urban ponds play a vital role in nutrient sequestration, flood prevention, and habitat sanctuaries. However, nutrient loading can reduce habitat effectiveness and promote harmful algae blooms. To reduce internal nutrient loads, a biological-chemical treatment strategy consisting of floating treatment wetlands (FTWs) and lanthanum were applied to two urban retention ponds, Densmore and Wilderness Ridge Ponds. To measure effectiveness, chlorophyll-a samples were collected and correlated with Sentinel-2. A novel band algorithm termed 3BR1 produced a strong correlation (R² = 0.72) to physical chlorophyll-a …

Thin Film Piezoelectric Energy Harvesting Nanostructured Materials: Tailoring Size, Porosity, Morphology Of Zinc Stannate Perovskites (Abx3), Christopher Munoz

Theses and Dissertations

Three dimensional (3D) piezoelectric zinc stannate (ZnSnO3) nanoweb arrays are synthesized using a combination of treatment methods deposited in PDMS thin films for electrochemical analysis of its piezoelectric response. Advantages of hydrothermal, molten salt, and solvothermal synthesis methods were leveraged to facilitate several chemical and surface engineering techniques. The combination of these treatments reduce the size of zinc stannate to approximately ~40nm-80nm weblike networks, much smaller than previously reported ZnSnO3 sub-micro cubes. Scanning electron microscopy (SEM) and X-Ray Diffraction (XRD) analysis reveal a mesoporous protonated tristannate (H2Sn3O7) nanoweb template with connecting wirelike strands having diameters ranging from 12-27nm across and …

Electrolysis Degradation Of Cyanuric Acid In Wastewater At Cu/Go Cathodes, Chioma Chinwe Nwakanobi

Theses and Dissertations

This work evaluates the development of electrochemical processes for the oxidative degradation of persistent organic chemicals in waste waters, specifically the oxidation of cyanuric acid in the presence of NaCl at Cu/GO cathodes and Ti anodes. The experiment used a graphene oxide doped copper mesh cathode to examine different concentrations of cyanuric acid (30 mg/L, 40 mg/L, and 50 mg/L) and various concentrations of NaCl electrolyte (0.007mol/L, 0.03mol/L, 0.07mol/L, 0.1mol/L, and 0.2mol/L). In addition, the effect of pH (2, 4, 6, and 8), and applied current (0.200A, 0.150A and 0.100A) were studied. The Cu/GO electrode played a central role in …

Chemical And Biological Catalysis Using A Functionalized Fluorinated Phthalocyanine, Mary Chiọma Okorie

Seton Hall University Dissertations and Theses (ETDs)

Phthalocyanines, a class of photosensitizers that generate ¹O₂ using visible light, have been widely used in a variety of applications such as catalysis, solid-state materials, and photodynamic therapy. A 3^rd generation, namely functionalized fluorinated phthalocyanines, F₄₈H₇(COOH)PcMetal, containing a carboxylic acid “tail” allows the Pc to be anchored onto supports such as metal oxides, producing a new family of supported photocatalysts, F₄₈H₇(COOH)PcZn-Oxides.

These new materials photooxidize toxic thioethers mainly to less toxic sulfoxides using visible light and air, a genuine green chemistry pathway. The catalysts are robust and survive reactive …

An Efficient And Chemoselective Method To Generate Arynes, Bryan Metze, Riley A. Roberts, Aleksandra Nilova, David R. Stuart

Chemistry Faculty Publications and Presentations

Arynes hold immense potential as reactive intermediates in organic synthesis as they engage in a diverse range of mechanistically distinct chemical reactions. However, the poor functional group compatibility of generating arynes or their precursors has stymied their widespread use. Here, we show that generating arynes by deprotonation of an arene and elimination of an “onium” leaving group is mild, efficient and broad in scope. This is achieved by using aryl(TMP)iodonium salts (TMP = 2,4,6-trimethoxyphenyl) as the aryne precursor and potassium phosphate as the base, and a range of arynophiles are compatible. Additionally, we have performed the first quantitative analysis of …

Studies On Electrochemical Hydrogen Isotope Separation, Liyanage Mayura Sankalpa Silva

All Dissertations

Graphene-integrated Proton Exchange Membrane (PEM) electrochemical cells have emerged as a novel area of scientific investigation in the realm of hydrogen isotope separation. Chemical Vapor Deposited (CVD) graphene has been especially useful due to its large-scale production capability for scaling-up purposes. The research described in this dissertation explores the role that inadvertent introduction of cations, notably ammonium and copper, during the CVD graphene transfer onto PEM substrates, such as Nafion, might play in affecting hydrogen ion transport and isotope separation in PEM electrochemical cells. An extensive review of existing literature exposed a gap concerning unintentional cation introductions during graphene transfer, …