Chemistry Commons^™

Model Of The Effect Of Voltage On Contact Angle In An Electrolytic Cell Reaction, Aaron Essilfie

Reviews, Analyses, and Instructional Studies in Electrochemistry (RAISE)

This paper investigates the hypothesis that the contact angle at the meniscus of an electrode-electrolyte can be altered during a redox reaction through the coupled understanding of electrowetting and capillarity rise. Recent studies in electrowetting have focused on dielectric surfaces but research on contact angle at the electrode-electrolyte surface is lacking. The study employs a basic electrolytic cell. By applying principles of electrowetting and capillary rise the research aims to understand the relationship between applied voltage and contact angle, to advancements in electrochemistry and microfluidics.

An Overview Of How To Measure The Kinetic Properties Of An Anode Material For The Chlorine Evolution Reaction, Cameron Vann

Reviews, Analyses, and Instructional Studies in Electrochemistry (RAISE)

The process of generating chlorine gas using electrolysis in aqueous systems is well established. However, a new process requires chlorine to be generated at high temperatures using molten salt. This harsh environment requires a new study of anode materials for the chlorine evolution reaction. Anode materials can be compared by their kinetic parameters, the transfer coefficient α and the exchange current i0. The basic theory of these properties as they relate to the chlorine evolution reaction has been detailed and an analysis method for finding these effective parameters has been shown and demonstrated.

Probing The Surface Structure Of Ferrocene Modified Electrodes Using Cyclic Voltammetry, Rebekah S. Stanley

Reviews, Analyses, and Instructional Studies in Electrochemistry (RAISE)

Modifying electrodes imparts new electrochemical properties for use in various applications. To fully understand these electrochemical properties the structure of the modified surface needs to be characterized. Cyclic voltammetry (CV) offers a quick and simple way to determine if the surface structure has been homogeneously modified even at low surface concentrations. Nonideal responses in CV scans give insights to the microenvironments and structure of the monolayer surface that may be indistinguishable in other techniques. Peak fitting CV data, coupled with other surface techniques, can further characterize the contributions and nature of these microenvironments and aid in structural determination.

Toxic Chocolate: An Investigation Of Heavy Metal Concentrations In Chocolate Products, Meredith E. Hoff

Student Scholarship

Many news organizations and scientific journals have recently reported high concentrations of lead and cadmium in chocolate products. The consumption of lead, cadmium, and other toxic metals can lead to numerous health impacts and impair development in children.1,2 Previous studies have specifically focused on the quantification of lead and cadmium in mainstream chocolate products, neglecting small businesses and the quantification of other heavy metals. This study addresses this disparity by analyzing the concentrations of lead, cadmium, barium, strontium, thallium, and mercury in lesser-known chocolate products from Castronovo Chocolate, Meridian Cacao Co., and Lidl. Two ICP-OES instruments and a direct mercury …

Cn Stretches Around 4.4 Microns Dominate The Ir Absorption Spectra Of Cyanopolycyclic Aromatic Hydrocarbons, Vincent J. Esposito, Ryan C. Fortenberry, Christiaan Boersma, Alexandros Maragkoudakis, Louis J. Allamandola

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Anharmonic quantum chemical computations reveal a strong, narrow (width = 0.075 μm) band in the 4.3–4.5 μm region of the absorption spectra of the cyano-substituted polycyclic aromatic hydrocarbons (CN-PAHs) cyanonaphthalene, cyanoanthracene, c yanophenanthrene, and c yanopyrene. This narro w windo w with intense IR lines implies that CN-PAHs of various shapes and sizes offer little variation in both wavelength and intensity in this region. Subsequently, this band can be used as a tracer for CN-PAHs. The distinct features making up the band are assigned to mixed vibrational states consisting of the CN stretch fundamental and various combination bands, including in-plane …

Melting Point Predictions Of Thermally Stable Ionic Liquids Using A Machine Learning Approach, Jarod Morris

Poster Presentations

Thermally robust ionic liquids hold promise as high-temperature solvents, heat transfer fluids, and high-performance lubricants. These ionic liquids, inspired by thermoplastics like PEEK and PES, incorporate peraryl functional groups that lend them high thermal stability, however they often have melting points greater than 100 °C. A broad liquid range is usually desirable in most applications, so finding thermally robust ILs with lower melting points would significantly enhance their applicability. In this study, machine learning models are developed to make predictions of melting points for these thermally stable ionic liquids using a process called quantitative structure-property relationships (QSPR). The methodology used …

Synthesis And Characterization Of Ox-Nad Derivatives, Juanita Monteiro-Pai

Honors Theses

Energy metabolism is complex, and NAD, or nicotinamide adenine dinucleotide, plays a huge role as an organic redox cofactor, driving metabolic reactions. The abundance of pathways dependent on NAD has led to an increase in the studies of NAD and its precursors. As a result NR, or nicotinamide riboside, is now a popular pharmaceutical taken to increase levels of NAD in the body. NR is not only a precursor to NAD, but a metabolite that is found in extracellular regions such as urine and blood. While this molecule should be an intracellular molecule, the fact that it is found in …

Purification And Isolation Of Α-Chloro-Β-Lactone Precursor Molecules, Matthew Ellis

Honors Projects

This research investigates the synthesis of α-chloro-β-lactone molecules, focusing on the production, isolation, and purification of two precursor compounds from chloroacetic acid and substituted benzaldehydes. While multiple methods were explored, including EDC, DIC, and DCC catalysis, DCC proved to be most effective in producing higher yields. However, challenges in purification arose due to the formation of byproducts, particularly with DCC, prompting further investigation for efficient extraction and purification techniques. DCC, however, shows a promising route for α-chloro-β-lactone synthesis, despite purification complexities.

Investigating The Impact Of Secondary Activation Time On The Adsorption Properties Of Activated Biochar For Arsenic Removal From Wastewater, Achyuth Bharadwaj Rayarao

Graduate Theses and Dissertations (2019 - present)

Biochar, a naturally occurring and renewable carbon material, becomes porous through activation. Activated biochar is an ideal candidate for use as an adsorbent. The objective of this study is to investigate whether activated biochar derived from Colorado soft pine serves as a better adsorbent and demonstrates enhanced adsorption capabilities after undergoing secondary physical activation at various activation times. The effect of secondary action time on physical adsorption properties drawn from the analysis of isotherm plots, surface areas and pore size patterns were examined by using a physisorption analyzer. Chemical structures were identified using both ultimate and proximate analyses, while porosity …

Photodynamic Treatment Of Staphylococcus Aureus With Non-Iron Hemin Analogs In The Presence Of Hydrogen Peroxide, Badhu Prashanthika Sivasubramaniam, Benjamin M. Washer, Yuichiro Watanabe, Kathryn E. Ragheb, J. Paul Robinson, Alexander Wei

Department of Chemistry Faculty Publications

Bacteria subjected to antiseptic or antibiotic stress often develop tolerance, a trait that can lead to permanent resistance. To determine whether photodynamic agents could be used to counter tolerance, we evaluated three non-iron hemin analogs (M-PpIX; M = Al, Ga, In) as targeted photosensitizers for antimicrobial photodynamic inactivation (aPDI) following exposure to sublethal H2O2. Al-PpIX is an active producer of ROS whereas Ga- and In-PpIX are more efficient at generating singlet oxygen. Al- and Ga-PpIX are highly potent aPDI agents against S. aureus and methicillin-resistant strains (MRSA) with antimicrobial activity (3 log reduction in colony-forming units) at nanomolar concentrations. The …

Using Student Interests To Explore Inclusion In Undergraduate Chemistry, Sonja Hoversten

CSB and SJU Distinguished Thesis

For students who are not chemistry majors, but who are on a career track requiring four chemistry courses, taking the final reactivity chemistry course (CHEM 251) for pre-health students can be daunting. For this reason, this research is focused on the CHEM 251 course at The College of Saint Benedict and Saint John’s University (CSBSJU) which is one of the four required chemistry courses for pre-medicine and some pre-physician assistant students, and all chemistry and biochemistry majors. Student perception of inclusion in the course increased through the implementation of group assignments including prompts for individual application of the material. The …

Design, Synthesis, Self-Assembly, And Applications Of Functional Bottlebrush Architectures Through Ring-Opening Metathesis Polymerization, Yipei Zhang

Arts & Sciences Graduate Student Theses and Dissertations

Shear-thinning hydrogels are a class of materials with unique rheological properties that enable them to undergo a reversible reduction in viscosity under shear stress, which allows for easy injection. The injectability of shear-thinning hydrogels is particularly important when considering their use in biomedical applications, such as drug delivery, tissue engineering, and wound healing. However, before advancing to these applications, it is crucial to evaluate the “injectability” of new shear-thinning hydrogels to avoid clogging of the needle for injection. Injectability is typically associated with determining suitable viscosity, storage/loss moduli, and other factors, such as injection force (e.g., needle length and gauge …

Zeolitic Imidazolate Framework-8 Encapsulated With Mo-Based Polyoxometalates As Surfaces With Antibacterial Activity Against Escherichia Coli, Mariam M. Abdelkhalek, Aya M. Mohamed, Rehab Z. Abdallah, Ghada E. Khedr, Rania Siam, Nageh K. Allam

Faculty Journal Articles

Bacterial infections represent a major global health concern, causing millions of deaths and a significant economic burden. The development of antibacterial nanoporous surfaces with potential mechano-bactericidal effects can revolutionize infection control practices. In this study, a hybrid material of zeolitic imidazolate framework-8 (ZIF-8) doped with phosphomolybdic acid (PMA) was synthesized and characterized by field emission scanning electron microscopy (FESEM), energy-dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), and N2 sorption isotherms. PMA@ZIF-8 performance as an antibacterial agent against E. coli was superior to that of its individual constituents, suggesting a synergistic effect of PMA and ZIF-8. The …

Outlining The Hidden Curriculum: Perspectives On Successfully Navigating Scientific Conferences, Eduardo J. Caro-Diaz, Marcy J. Balunas, Lesley Ann Giddings, Sandra Loesgen, Brian T. Murphy, C. Benjamin Naman, Christine E. Salomon, Kevin J. Tidgewell, Jaclyn M. Winter

Chemistry: Faculty Publications

Scientific conferences and meetings are valuable opportunities for researchers to network, communicate, and develop knowledge. For early career scientists, conferences can also be intimidating, confusing, and overwhelming, especially without having adequate preparation or experience. In this Perspective, we provide advice based on previous experiences navigating scientific meetings and conferences. These guidelines outline parts of the hidden curriculum around preparing for and attending meetings, navigating conference sessions, networking with other scientists, and participating in social activities while upholding a recommended code of conduct.

Incorporating Solvent Effects In Dft: Insights From Cation Exchange In Faujasites, An T. Ta, Ayoub Daouli, R. Seaton Ullberg, Eric Fonseca, Vanessa Proust, Agnès Grandjean, Richard G. Hennig, Hans Conrad Zur Loye, Michael Badawi, Simon R. Phillpot

Faculty Publications

Zeolites are versatile materials renowned for their extra-framework cation exchange capabilities, with applications spanning diverse fields, including nuclear waste treatment. While detailed experimental characterization offers valuable insight, density functional theory (DFT) proves particularly adept at investigating ion exchange in zeolites, owing to its atomic and electronic resolution. However, the prevalent occurrence of zeolitic ion exchange in aqueous environments poses a challenge to conventional DFT modeling, traditionally conducted in a vacuum. This study seeks to enhance zeolite modeling by systematically evaluating predictive differences across varying degrees of aqueous solvent inclusion. Specifically focusing on monovalent cation exchange in Na-X zeolites, we explore …

Anodic Cyclizations To Form Alkaloid Ring Systems And The Role Of The Second Oxidation Step, Zachary Tyler Medcalf

Arts & Sciences Graduate Student Theses and Dissertations

In chapter 1 we will explore the essential background on electrochemistry and anodic cyclization reactions, laying the foundation for understanding the subsequent chapters. In chapter 2, we will explore the mechanistic model established for anodic olefin coupling reactions and the importance of the second oxidation step in the success of these reactions. We showed how a fast second oxidation step can be used to push an anodic cyclization down a kinetic pathway. We will also explore how this step impacts the generation of product in photoelectron-transfer initiated radical cation reactions. It is evident that a fast second oxidation step alone …

Investigation Of Lignin Solubilization Using Quantum Chemical Calculations In Constrained Media, Leo Sanzone

Arts & Sciences Undergraduate Showcase

Lignin is a common, yet complex polymer found in a majority of vascular plants. The polymer can easily be functionalized, and it is a readily available and renewable source of carbon-based material without a petrol source. There are various methods to allow for the dissolution of lignin, one of which involves the use of H₂O and CO₂ in supercritical conditions. This particular solution bends the normal solvation rules and allows for multiple instances of H-bonding interactions.

By using Density Functional theory, this study aims to identify the molecular interactions of guaiacol (the most basic fragment of lignin) …

Outlining The Hidden Curriculum: Perspectives On Successfully Navigating Scientific Conferences, Eduardo J. Caro-Diaz, Marcy J. Balunas, Lesley Ann Giddings, Sandra Loesgen, Brian T. Murphy, C. Benjamin Naman, Christine E. Salomon, Kevin J. Tidgewell, Jaclyn M. Winter

Chemistry: Faculty Publications

Scientific conferences and meetings are valuable opportunities for researchers to network, communicate, and develop knowledge. For early career scientists, conferences can also be intimidating, confusing, and overwhelming, especially without having adequate preparation or experience. In this Perspective, we provide advice based on previous experiences navigating scientific meetings and conferences. These guidelines outline parts of the hidden curriculum around preparing for and attending meetings, navigating conference sessions, networking with other scientists, and participating in social activities while upholding a recommended code of conduct.

Peace With Painful Memories, Mona Muzammil, Muzammil Arshad, Washain Muzammil

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

This Book helps you identify and heal from childhood emotional neglect so you can be more connected and emotionally present in your life.

Do you sometimes feel like you’re just going through the motions in life? Do you often act like you’re fine when you secretly feel lonely and disconnected? Perhaps you have a good life and yet somehow, it’s not enough to make you happy. Or perhaps you drink too much, eat too much, or risk too much to feel something good. If so, you are not alone and you may be suffering from emotional neglect.

Are you one …

Enabling More Efficient Solar Thermal Energy Production And Storage, Allan Wilson

Poster Presentations

Concentrated Solar Power (CSP) stores & transfers energy using a Thermal Energy Storage Fluid (EIA AEO 2022)

Formation Of Diazirine Functionality For Propellant Applications, Abby Mock

Poster Presentations

Overall, this research focuses on a cost-effective approach which minimizes synthetic overhead when assembling compounds with diazirine functionality. The goals are to prevent the surplus use of ammonia in the formation of the diaziridines and use electrochemistry to perform the oxidation of diaziridines. In addition, this project will evaluate the efficiency of different diazirine molecules as propellants.

The Effects Of Free Volume And Processing On The Development Of Gas Separation Membranes, Jacob Schekman

Dissertations

Structure, thermal, mechanical, gas transport, and free volume properties of thiol-ene based systems are investigated and discussed. In the pursuit of generating low energy-cost polymer membranes for gas separation, it became apparent that UV-curing of thiol-ene materials presented several routes toward achieving this goal. Network structure plays a vital role in determining the gas transport properties of membrane materials. UV photopolymerization techniques provide a means to rapidly vitrify network morphologies which can be tuned depending on choice of monomer. Thiol-ene monomers offer a broad range of precursor materials from which to choose for the design of functional membrane materials.

Chapter …

Synthesis Of Poly-N-Methylated Peptides Against Malaria, Kaitlyn Watson

Theses & Dissertations

Malaria, a life-threatening global health concern, is primarily targeted by mainstream treatments such as artemisinin-based combination therapies, focusing on the blood stage of the disease. Primaquine, one of the few drugs active against the liver stage, faces challenges with reports of resistance in Plasmodium vivax strains and relapsing infections. With the scarcity of liver-stage-targeting drugs and increasing cases of drug-resistant malaria, the World Health Organization emphasizes the urgent need for novel therapeutic agents. Marine organisms are a rich source of new bioactive compounds, and extracts from the Antarctic Sea sponge Inflatella coelosphaeroides revealed new N-methylated peptides exhibiting promising antimalarial activity, …

Enabling High-Rate Thermoplastic Composite Manufacturing Through Structure-Processing-Property Relationships Of Polyphenylene Sulfide, Lina Ghanbari

Dissertations

In this dissertation, relationships between polyphenylene sulfide (PPS) chain structure and melt processing parameters are linked to thermoplastic composite (TPC) properties and mechanical performance. Deviations from linear PPS structure and the formation of branching/crosslinked moieties upon exposure to TPC manufacturing steps presents an opportunity to systematically uncover the interdependencies of melt-state thermal history on polymer rheology, crystallization, crystal structure, and translate these properties to the continuum level. This work first explores unreinforced PPS and how the formation of non-linear chain architectures yield altered rheological states when held at melt processing temperatures. These hindered chains exhibit unconventional crystallization behavior and non-uniform …

Development Of An Enhanced Sampling Workflow To Accelerate Molecular Docking With Sparse Biophysical Information, Zachary Stichter

Masters Theses & Specialist Projects

Rapid docking of flexible biological macromolecules remains a significant open challenge in protein structure determination. While rigid docking is relatively simple with toolkits such as TagDock, a key obstacle to rapid flexible docking is the complexity and roughness of the free energy surface associated with protein conformational motion (often termed the many-minima problem), meaning conventional molecular dynamics methods do not effectively sample protein conformations near the interaction complex in accessible timescales. Methods such as metadynamics and replica exchange molecular dynamics exist to ameliorate this obstacle, yet these methods use nonphysical biases or random swaps to enhance sampling. In contrast, high …

A Chemical And Historical Analysis Of Beer: Discovering Brewing Styles And Beer Stages, Alexander Taylor '24

Honor Scholar Theses

This interdisciplinary project is designed to explore both the compositional qualities of beer during the brewing process and its impact on society from a cultural, economic, and social viewpoint. Comparing various styles of beer against each other in a historical, societal, and chemical lens allows for a deeper understanding of what creates a beer’s identity, and what makes it different from other styles. Here we analyzed two different styles of beer, a bock lager and a saison ale, in order to determine their chemical composition through their developmental stages to their final product. Based on previously published research and extended …

Learning, Optimizing, And Simulating Fermions With Quantum Computers, Andrew Zhao

Physics & Astronomy ETDs

Fermions are fundamental particles which obey seemingly bizarre quantum-mechanical principles, yet constitute all the ordinary matter that we inhabit. As such, their study is heavily motivated from both fundamental and practical incentives. In this dissertation, we will explore how the tools of quantum information and computation can assist us on both of these fronts. We primarily do so through the task of partial state learning: tomographic protocols for acquiring a reduced, but sufficient, classical description of a quantum system. Developing fast methods for partial tomography addresses a critical bottleneck in quantum simulation algorithms, which is a particularly pressing issue for …

Development Of Chiral Lewis Base Catalysts For Chlorosilane-Mediated Asymmetric C-C Bond Formations, Changgong Xu

Theses and Dissertations

The chiral hydrazine is a crucial structural motif that serves as pivotal structural elements in numerous natural products and biologically significant molecules. We are particularly interested in the catalytic asymmetric reduction of hydrazones, as well as the catalytic asymmetric propargylation and allenylation of hydrazones, because they provide direct pathways to these enantio-enriched chiral building blocks. In this work, we will explore the potential of two different categories of chiral Lewis base catalysts in the said transformations.

Developed by another student in our group, axial-chiral 3,3’-triazolyl biisoquinoline N,N’-dioxides derived catalysts are tested and demonstrated its capability in activating various hydrazone …

Tpm^Ph Derivative Of Tungsten; Hydrogen-Bonding In 7-Coordinate Cation Complex, Olivia Ryon Simcox

Undergraduate Honors Thesis Collection

Tpm^Ph, or tris(3-phenylpyrazolyl)methane reacts with tungsten hexacarbonyl to form the ligand-metal complex tris(3-phenylpyrazolyl)methane tungsten tricarbonyl, or Tpm^PhW(CO)3. The further complexes of Tpm^PhW(CO)3 and Tpm^PhMo(CO)3 are not known. This project aims to explore how the addition of a phenyl substituent to the pyrazole ring on Tpm impacts the synthesis of [Tpm^PhW(CO)3I]+X– and [Tpm^PhW(CO)3H]+X–. The inclusion of this phenyl substituent may impact the possible hydrogen bonding of then hydrogen contained in the carbon-hydrogen bond. This work aims to explore the extent of hydrogen-bonding of the carbon-hydrogen bond of the Tpm^Ph ligand in cationic metal complexes.

Using Ion Mobility Mass Spectrometry In Conjuction With Derivatization Methods To Enhance The Separation Of Different Steroid Isomers, Shadrack Lucas

All Theses

One of the major problems facing analytical chemistry challenge is the isomers separation, due to their closely related molecular structures and physicochemical properties. Therefore, in this thesis, we have performed the separation of steroid isomers through the use of ion mobility mass spectrometry, using various chemical approaches. Ion mobility is an effective high-resolution separation techniques that utilizes the mobility of ions in the gas-phase environment. A useful tool for isomeric analysis due to the ability to separate different isomeric classes of steroids according to their varied collision cross-sections, which is achieved by taking advantage of differences in ion mobility.

Moreover, …