Chemistry Commons^™

Development Of Bifunctional Electrocatalyst For The Electrically Rechargeable Zinc Air Batteries, Thiruvenkatam S

Theses and Dissertations

The spontaneous reaction between zinc and oxygen in an alkaline medium is exploited in non-rechargeable aqueous zinc-air batteries (ZABs) to generate useful electricity. The primary ZAB has a rich history as it was used in tramways, railway signalling and it is being used in hearing aids, pacemakers, etc. The success of primary ZABs led to the development of two types of rechargeable ZAB, namely, mechanically rechargeable ZAB (mrZAB) and electrically rechargeable ZAB (erZAB). In mrZABs, the exhausted anode and electrolyte are replaced periodically. Whereas the chemistry of primary ZAB is reversed using suitable electrocatalysts in erZABs. Electrocatalysts used in erZABs …

Thermal Destabilization Of Azurin By Fatty Acid Ionic Liquids, Brandon Burrell, Austin K. Clark, Achismita Dutta, Esha Prajapati, Sierra Cottle, Andrew Ogungimi, Justin Burrell, Timothy D. Vaden

STEM Student Research Symposium Posters

Azurin is a mixed-structure redox protein involved in bacterial denitrification. Previous studies have shown that azurin is destabilized by imidazolium chloride ionic liquids (ImCl ILs) that can form micelles in aqueous solution, likely by micellar encapsulation. In these ImCl ILs the micelles form from the imidazolium cations. A relatively new class of ionic liquids is fatty acid ionic liquids (FAILs), in which the anion is a fatty acid. In FAILs micelles can form from the fatty acid anions. This presentation presents the results of a thermal unfolding study of azurin in the presence of FAILs in solution. The FAILs tetramethylguanidinium …

Attendance At Virginia Academy Of Science Meetings: A Report Of The Panel Discussion Held By The Chemistry Section Of The Virginia Academy Of Science, Tom Devore

Virginia Journal of Science

Since the attendance in the Chemistry Section at the Virginia Academy of Science (VAS) spring meetings has not returned to the numbers attending prior to the cancellation of the 2020 meeting due to the Covid pandemic, a roundtable discussion was held as part of the 2023 VAS Annual Meeting at the College of William and Mary on May 25, 2023 to discuss possible ways to increase attendance at future meetings. This is a report of the topics discussed and the suggestions made.

Solution Combustion Synthesis And Characterization Of Fumarolic Mineral Dolerophanite, Copper (Ii) Oxide Sulfate, Eric J. Cyganowski

Chemistry & Biochemistry Theses - Archive

Dolerophanite Cu₂OSO₄ is a rare mineral found almost exclusively in the fumaroles of volcano systems and is sensitive to temperature and humidity conditions. It has a monoclinic C2/m crystal structure characterized by two-dimensional layers composed of sulfate anions dispersed amongst copper (II) oxide backbones. There has been recent interest in dolerophanite due to the magnetic properties of its Kagome-like lattice as well as its potential use as a photocatalyst or Li-ion battery electrode. Literature on the material however has been limited by the available synthesis strategies. As such, this thesis work presents a novel strategy …

Frsc 480-002: Forensic Microscopy, Fisher David

Chemistry, Environmental and Forensic Science Syllabi

No abstract provided.

Polarizable Amoeba Force Field Predicts Thin And Dense Hydration Layer Around Monosaccharides, Luke A. Newman, Mackenzie G. Patton, Breyanna A. Rodriguez, Ethan W. Summer, Valerie Vaissier Welbourn

Chemistry & Biochemistry Faculty Publications

Polarizable force fields crucially enhance the modeling of macromolecules in polar media. Here, we present new parameters to model six common monosaccharides with the polarizable AMOEBA force field. These parameters yield a thinner, but denser, hydration layer than that previously reported. This denser hydration layer results in eliminating non-physical aggregation of glucose in water-an issue that has plagued molecular dynamics simulations of carbohydrates for decades.

Examining The Effectiveness Of Oiled Ballast Water Treatment Processes: Insights Into Hydrocarbon Oxidation Product Formation And Environmental Implications, Maxwell L. Harsha, Danielle E. Verna, Yanila Salas-Ortiz, Eduardo Osborn, Eduardo Turcios Valle, Aleksandar I. Goranov, Patrick G. Hatcher, Ana M. Aguilar-Islas, Patrick L. Tomco, David C. Podgorski

Chemistry & Biochemistry Faculty Publications

Ballast water released from ships into coastal environments has been identified as a mechanism that introduces contaminants of concern into coastal ecosystems. This study investigates the treatment processes employed at a ballast water treatment facility in Valdez, Alaska, that remove hydrocarbons from unsegregated ballast water. Specifically, the aim is to quantify and characterize hydrocarbons of emerging concern, known as dissolved hydrocarbon oxidation products (HOPs) and heavy metals (HMs), throughout the treatment process. Specialized analytical techniques were employed, such as non-volatile dissolved organic carbon analysis, fluorescence spectroscopy, Fourier transform-ion cyclotron resonance-mass spectrometry, and inductively coupled plasma triple quadrupole mass spectrometry. Results …

A Spectrophotometric Determination Of Strontium Complexation With Methylthymol Blue, Adebayo Comlan Djanman

Browse all Theses and Dissertations

This study examines the complexation behavior of methylthymol blue (MTB) with strontium, particularly focusing on its application in addressing environmental concerns related to radiotoxic 90Sr. Using spectrophotometric techniques, the binding interactions were analyzed at pH = 7.50, 9.60, and 12.20. Results indicate that MTB forms a 1:1 complex with strontium at pH = 7.50, while at pH = 9.60 and 12.20 were assumed to influence complexation due to changes in ligand deprotonation and electrostatic interactions. Equilibrium constants (K1) = 22 (± 2) and molar absorptivities, ε1 = 6.3 x 10^3 (± 0.0008) L·mol⁻¹·cm⁻¹, and ε2 = 9.73 x (± 0.2)10^3 …

Investigation Of Ion Pairing And Clustering Leading To The Nucleation Of Fluorite Using Ion Selective Electrode Potentiometry, Courtney L. Crone

Browse all Theses and Dissertations

Previously, mineral nucleation was described by Classical Nucleation Theory (CNT), a theory based on the thermodynamic properties of bulk materials. However, an alternative model, known as the Prenucleation Cluster Pathway, has been increasingly used to describe nucleation of minerals. This model considers the presence of thermodynamically stable ion clusters known as “prenucleation clusters” (PNCs). In the present research, the nucleation mechanism of calcium fluoride was investigated to identify evidence of PNCs by means of the ion-selective electrode (ISE) method, where a CaCl2 solution was titrated into a NaF solution while investigating the effects of saturation level and the aqueous ratio …

Effects Of Geometric Isomerism On Benzothiazole-Carbazole Based Tadf Emitters In Poly(Arylene Ether)S, Grace Olive

Browse all Theses and Dissertations

Thermally activated delayed fluorescence (TADF) small molecules have dominated the literature for their use in OLED devices. The use of TADF polymers has been employed to correct for processing issues that small molecules face, providing increased thermal stability and supportive electronic structures. A TADF chromophore based on a 2-(2,6-difluorophenyl)-benzothiazole-carbazole donor-acceptor pair was synthesized via a copper (I) catalyzed reaction. The chromophore exhibited peak absorption at 340 nm and emission at 477 nm. The resulting chromophore was incorporated into a poly(arylene ether) (PAE) backbone via nucleophilic aromatic substitution (NAS) with 4,4’-biphenol, 4,4’-difluorodiphenyl sulfone, and 2-(2,6-difluorophenyl)-benzothiazole as comonomers. UV/Vis analysis of the …

Synthesis Of Hydroxycinnamate Derivatives And Characterization Of Bioactivity As Radical Scavengers And Α-Glucosidase Inhibitors, Cate Simmermaker

University of the Pacific Theses and Dissertations

Hydroxycinnamic acids (HCAs), a class of polyphenols commonly found in regularly consumed fruits and vegetables, have been investigated for efficacy as radical scavengers and glycosidase inhibitors. These compounds could mitigate the negative health effects of free radicals in oxidative stress diseases including neurodegeneration, cancer and diabetes. The HCAs investigated were caffeic acid (1), p-coumaric acid (2), ferulic acid (3), and sinapic acid (4). The compounds were derivatized with synthetically prepared amino acid esters through a four-step synthesis including protective acetylation, chlorination of the carboxylic acid, amidation, and subsequent deprotection of all applied protecting groups. The inclusion of diverse derivative groups …

The Relationship Between Metacognition, Study Strategies, And Students’ Performances In General Chemistry And Organic Chemistry Courses, Nghiem Uy Tieu

Graduate Theses, Dissertations, and Problem Reports (ETD)

Many students find General Chemistry challenging, and studies have shown a link between students’ grades in chemistry and a decrease in interest in STEM fields. Similarly, Organic Chemistry has also been typically identified as a difficult course for many undergraduate students and has a notoriously high failure rate. Numerous studies have explored various methods to enhance students’ performance and experience in both General Chemistry and Organic Chemistry, but there hasn’t been much focus on students’ study strategies. In addition, metacognition, the skill of thinking about one’s thinking, had been proven in studies as a vital role in enhancing students’ achievements. …

Photoluminescence Switching In Quantum Dots Connected With Fluorinated And Hydrogenated Photochromic Molecules, Ephraiem S. Sarabamoun, Jonathan M. Bietsch, Pramod Aryal, Amelia G. Reid, Maurice Curran, Grayson Johnson, Esther H. R. Tsai, Charles W. Machan, Guijun Wang, Joshua J. Choi

Chemistry & Biochemistry Faculty Publications

We investigate switching of photoluminescence (PL) from PbS quantum dots (QDs) crosslinked with two different types of photochromic diarylethene molecules, 4,4'-(1-cyclopentene-1,2-diyl)bis[5-methyl-2-thiophenecarboxylic acid] (1H) and 4,4'-(1-perfluorocyclopentene-1,2-diyl)bis[5-methyl-2-thiophenecarboxylic acid] (2F). Our results show that the QDs crosslinked with the hydrogenated molecule (1H) exhibit a greater amount of switching in photoluminescence intensity compared to QDs crosslinked with the fluorinated molecule (2F). With a combination of differential pulse voltammetry and density functional theory, we attribute the different amount of PL switching to the different energy levels between 1H and 2F molecules which result in different potential barrier …

Quantification Of Antiretroviral Drug Emtricitabine In Human Plasma By Surface Enhanced Raman Spectroscopy, Marguerite R. Butler, Terry A. Jacot, Sucharita M. Dutta, Gustavo F. Doncel, John B. Cooper

Chemistry & Biochemistry Faculty Publications

In this study, reproducible label-free detection and quantification of the antiretroviral drug emtricitabine (FTC) down to 78 ng/mL in human plasma by surface enhanced Raman spectroscopy (SERS) is presented. A novel plasma sample pretreatment method using silver nitrate and silver colloidal nanoparticles (Ag CNPs) was used to prepare the plasma samples for analysis. The pretreated plasma samples were evaporated to dryness on an aluminum surface and a computer-controlled Raman scanning system was used to collect spatially resolved SERS spectra of the entire surface. Calibration curves of commercial human plasma samples containing FTC in a concentration range of 5000 to 78 …

Differentiation Of Human, Dog, And Cat Hair Fibers Using Dart Tofms And Machine Learning, Laura Ahumada, Erin R. Mcclure-Price, Chad Kwong, Edgard O. Espinoza, John Santerre

SMU Data Science Review

Hair is found in over 90% of crime scenes and has long been analyzed as trace evidence. However, recent reviews of traditional hair fiber analysis techniques, primarily morphological examination, have cast doubt on its reliability. To address these concerns, this study employed machine learning algorithms, specifically Linear Discriminant Analysis (LDA) and Random Forest, on Direct Analysis in Real Time time-of-flight mass spectra collected from human, cat, and dog hair samples. The objective was to develop a chemistry- and statistics-based classification method for unbiased taxonomic identification of hair. The results of the study showed that LDA and Random Forest were highly …

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 …

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, …

Cost Analysis Of Adsorption Based Air Capture Of Co2, Mona Muzammil, Muzammil Arshad, Muazzam Arshad

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Chemistry)

Carbon dioxide (CO2) capture and conversion to value added products, such as chemicals, polymers, and carbon-based fuels represents a promising approach to transform a potential threat to the environment into a value-added product for long term sustainability. Emerging Carbon Capture Technologies: Towards a Sustainable Future provides a multidisciplinary view of the research that is being carried out in this field, covering materials and processes for CO2 capture and utilization and including a broad discussion of the impact of novel technologies in carbon capture on the energy landscape, society and climate. Of interest to students, researchers and professionals in industries related …

Introductory Chemistry, Mona Muzammil

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Chemistry)

Introductory Chemistry, this edition is designed for a one-semester, introductory or preparatory chemistry course. Students taking this course need to develop problem-solving skills-but they also must see why these skills are important to them and to their world. Introductory Chemistry extends chemistry from the laboratory to the student's world. It motivates students to learn chemistry by demonstrating how it plays out in their daily lives.

This book draws students into the course through engagement and building their foundational knowledge – while introducing new content and resources to help students build critical thinking and problem-solving skills. allowing students flexibility and ensuring …

Contributions Of Tunneling In 8Π-6Π Electrocyclic Cascade Reactions Of Bicyclo[4.2.0]Octa-2,4-Diene Moieties, Ishika Jain, Claire Castro, William L. Karney

Featured Student Work

Six-electron electrocyclic reactions usually require relatively high temperatures; however recent research has shown that such reactions can occur at significantly lower temperatures in biosynthetic and biomimetic pathways. Pathways resulting in bicyclo[4.2.0]octa-2,4-diene moieties arise from thermally allowed 8π-6π electrocyclization cascade reactions of 1,3,5,7-octatetraenes, as in the biosynthesis of endiandric acids, elysiapyrones, and numerous other natural products. We report multidimensional tunneling calculations to explore the possible contribution of heavy-atom tunneling (e.g. by carbon) to biosynthetic pathways and biomimetic syntheses, and thus to provide a more complete picture of biochemical kinetics. M06-2X/cc-pVDZ calculations on the 8π-6π cascade cyclizations of methylated octatetraene model systems …

Phosphorus And Its Role In Chemical Evolution, Asbel Gonzalez

PANDION: The Osprey Journal of Research and Ideas

Phosphorus is a minor element with a cosmic abundance of about 105.5 atoms per 1012 H atoms (Boudreaux, n.d.). Phosphorus was depleted as a volatile throughout the developing solar system, and as a result, volatile forms of phosphorus would have been minimal, even in the colder regions of the solar nebula. Despite its low abundance, phosphorus minerals play key roles in planetary petrology, including through the formation of phosphate minerals that trapped volatiles and rare Earth elements, and in the formation of metal phosphides that may have served as nucleation sites for kamacite and taenite crystal growth in minor planet …

Exploring Students’ Epistemological Understanding Of Atomic Structure Models, Claire V. Ward, Morgan Balabanoff

The Cardinal Edge

Developing a robust understanding of atomic structure and the nature of matter is foundational across chemistry and STEM courses. The development of this concept is challenging because it relies on models to illustrate something not directly observable. Scientific models are important tools used to explain phenomena, particularly phenomena that are not directly observable. In general chemistry, students are typically asked to consider four different models: (1) the particle model, (2) the nuclear model, (3) the Bohr model, and (4) the Quantum model. Each depiction has its own advantages and limitations, where instructors introduce each model to explain specific parts of …

Exploring Retrieval Difficulties And Self-Confidence In An Assessment Of General Chemistry Students, Karen Julian, Morgan Balabanoff

The Cardinal Edge

Developing self-assessment skills is an important aspect of learning. Framed by assessment developed for the year-long sequence of general chemistry, students were asked to rate their ability to answer conceptual questions. Using cognitive interviews, this study revealed that people rely on a range of characteristics other than content knowledge to assess their confidence, including doubt, retrieval difficulty, and test-taking methods. These findings imply that more explicit instruction may be required to encourage correct self-assessment. Students can develop their metacognitive skills and calibrate their perceived ability by completing examinations meant to emphasize content knowledge gaps.

Bioinformatic Analysis Of The Interaction Of Evc And Evc2 Proteins, Md Atikul Islam Mamun

Electronic Theses and Dissertations

Protein to protein interactions are significant to various biological processes, functioning, and the regulation of cells and organisms. Proteins perform essential cellular tasks and often work together in complexes, enabling specific functions like enzymatic activity, signal transduction, DNA replication, and cell division. These interactions are important in signaling pathways, allowing proteins to interact sequentially, leading to specific cellular responses. Some proteins rely on chaperones to fold correctly, and protein to protein interactions enhance stability, preventing degradation.

Researchers at Stanford University School of Medicine discovered that EvC syndrome is related to a malfunction in the Hedgehog (Hh) signaling pathway. They found …

Studying The Stability Of Collagen/Heparin Coatings To Be Used In Cell Therapy Applications, Gavin Mussino

Biological Sciences Undergraduate Honors Theses

This honors thesis aims to investigate the reusability and performance of cell coatings for cell therapy applications. Cell therapy, which involves the use of human cells to repair or replace damaged tissues, holds immense potential for medical advancements. However, ensuring the survival and functionality of transplanted cells remains a significant challenge. We focused on studying the effectiveness of coatings applied to cells for improved cell growth and viability. The research project involved the preparation of the coatings using a layer-by-layer method and the subsequent seeding of cells. The coated cells were then subjected to a series of experiments to assess …

Leveraging Non-Covalent Interactions Between Small Organic Molecules And Inorganic Scaffolds In The Design Of Advanced Materials, Jonathan Lefton

Chemistry Theses and Dissertations

Powder diffraction is a powerful tool for studying crystal structures, especially as it relates to interactions of small organic molecules with inorganic compounds. The first part of this dissertation involves small organic ligands interacting with metal-organic framework, MOF-74. The first and simplest iteration involves the crystal structure solution of a neat, liquid loading of n-propylmercaptan to the open metal sites within the MOF-74 pores. Later studies investigate the leveraging of a similarly sized bitopic ligand in the solution loading of 1,2-ethanedithiol, which results in the amorphization of MOF-74. Having no crystallinity, amorphous or severely defected materials can be a …

The Investigation Of Singlet Fission From The Perspective Of Hierarchy Of Pure States (Hops), Tao (James) Chen

Chemistry Theses and Dissertations

This thesis provides a preliminary investigation of singlet fission from the perspective of Hierarchy of pure states (HOPS), which provides a numerical exact solution for the investigation of a series of open quantum systems. Since the inception of the concept of singlet fission about half a century ago, this photo-physical process has attracted the attention of a multitude of researchers and has been extensively studied theoretically and experimentally. However, these previous methods for the investigation of singlet fission focus more or less on tackling the underlying mechanisms of singlet fission from the perspective of perturbation. So far, the HOPS method …

The Investigation Of Singlet Fission From The Perspective Of Hierarchy Of Pure States (Hops), Tao (James) Chen

Chemistry Theses and Dissertations

This thesis provides a preliminary investigation of singlet fission from the perspective of Hierarchy of pure states (HOPS), which provides a numerical exact solution for the investigation of a series of open quantum systems. Since the inception of the concept of singlet fission about half a century ago, this photo-physical process has attracted the attention of a multitude of researchers and has been extensively studied theoretically and experimentally. However, these previous methods for the investigation of singlet fission focus more or less on tackling the underlying mechanisms of singlet fission from the perspective of perturbation. So far, the HOPS method …

Clear As Glass: Novel Antibiotic Glasses Vitrified From Solution, Claire Lamberti

Chemistry Theses and Dissertations

The World Health Organization (W.H.O.) has maintained a list of essential medicines since 1977 (1). This list contains the medications considered to be the most effective and of the utmost importance to the needs of worldwide healthcare systems. If new forms of these drugs can be created, they can be studied for potential stability and transportation purposes, as well as drug delivery mechanisms. There are strategies to try and improve the physicochemical properties including forming polymorphs, salts, cocrystals, and amorphous formulations. There are issues with these techniques, and a large one is that in most cases the crystal structures of …

The Decomposition Of Normal Vibrational Modes In Different Chemistry Problems, Mateus Macedo Quintano

Chemistry Theses and Dissertations

The least action principle yields the Euler-Lagrange equations, which explain molecular vibrations in minimizing action. Subsequently, the Lagrangian gives rise to the equations of motion using the Euler-Lagrange equations. We can then solve the characteristic value problem to obtain normal vibrational modes. Ultimately, the vibrational spectrum of a molecule can be extracted from the characteristic values. Normal coordinates are linear combinations of internal or Cartesian coordinates. However, the delocalization of normal vibrational modes across the molecule restricts the direct use of normal mode frequencies and force constants for measuring bond strength. From the force constant matrix and the normal mode …