Chemistry Commons^™

Hydrolytically Degradable Thermosets With Tunable Degradation Profiles Via Ketal-Based Crosslinks, Benjamin Alameda

Dissertations

Thermoset polymer networks are ubiquitous in the construction of high-performance materials due to their excellent mechanical properties, solvent resistance, and thermomechanical performance. However, the crosslinked structure that instills these materials with favorable performance also makes them incredibly resistant to degradation and are nearly impossible to recycle – adding to the ever-growing problem of plastic pollution. Hydrolytically degradable thermosets have emerged as a potentially sustainable alternative to traditional thermosets by affording networks that are inherently degradable in aqueous environments. This dissertation focuses on the development of hydrolytically degradable thermoset networks with tunable degradation behavior through the implementation of ketal-based crosslinks. Given …

Controlling Unequal Surface Energy Results Caused By Test Liquids: The Case Of Uv/O3 Treated Pet, Bilge N. Altay, Paul D. Fleming, Md Arifur Rahman, Alexandra Pekarovicova, Bruce Myers, Cem Aydemir, Arif Karademir

Articles

Ultraviolet/ozone (UV/O3) treatment has been reported to be an effective method to modify properties such as wettability, adhesion or adsorption of plastic surfaces. The change in the surface is measured by contact angle analysis, which employs liquids and their surface tensions (ST) to estimate the surface energy (SE). We found two different practices in the scientific community: (1) the majority of researchers adopted the ST value of liquids from the literature, while (2) other researchers conducted real-time measurements in the lab under ambient conditions prior to SE estimation. To the best of our knowledge, there is no study that compares …

The Effects Copper Has On Casting Glass, K. Malika Haver

Honors Projects

The aim of this honors project was to discern the difference between how various types of copper reacted with glass. The two disciplines that were connected were chemistry and glassblowing. The basic components learned in chemistry were applied to glass with an end goal of a project installation that visualized the discoveries with copper. The glassblowing technique used was lost wax casting, and the two types of copper used were copper foil and fine copper metal powder. The copper was found to turn the glass into various blues with the intensity and darkness of the blues being dependent on the …

Metal Complexes Of Redox Active Ligands, Alexandra Chaparro, Parker Keller

Chemistry & Biochemistry Student Scholarship

Alexandra Chaparro ’22, Major: Biochemistry

Parker Keller ’24, Major: Chemistry

Mentor: Dr. Maria Carroll, Chemistry and Biochemistry

Our research focuses on synthesizing and studying the properties of metal complexes that contain redox active ligands. Ligands are molecules or ions that can bind to a metal ion, and this particular class of ligands is interesting because they can either accept or lose electrons. We synthesized zinc complexes, in order to measure the reduction potentials of the ligands, which provide information about the ease with which they accept electrons. We then synthesized iron complexes and determined their structures. These complexes are potentially …

Investigating Ionic Current Rectification As A Means Of Controllable Drug Delivery Using Silica Nanoparticles And Nano Porous Membranes, Katie L. Nolan

Honors College Theses

This project investigates a novel ionic current rectification (ICR) phenomenon created by the opening and closing of nanopores by charged silica nanoparticles (SNPs) under electrophoretic flow. This voltage-controlled opening and closing of the pores can be exploited to allow delivery of nicotine through the pores at programmable intervals. The ICR phenomenon was thoroughly investigated by varying pH, buffer concentration, SNP concentration, and applied voltage range. The mechanism was also verified by testing with a 2-, 3-, and 5-electrode system. Potential cake layer formation was demonstrated in a longer ICR test, and the implications of this on the drug delivery mechanism …

Synthesis, Characterization And Activity Of Palladium Catalysts On The Dual Support Of Cerium And Aluminum Oxides, Jihyeon Park

Theses and Dissertations

The effects of sequence of impregnation (Pd on cerium oxides -alumina and cerium oxides on Pd-alumina) and calcination temperature (500 ℃ and 850 ℃) on the catalytic oxidation of methane under lean conditions were investigated. The catalysts were prepared by a combination of impregnation, slurry and vortexing methods. The catalysts had 4.7 wt.% Pd and 10.7 wt.% Ce based on inductively coupled plasma optical emission spectrometry (ICP-OES) analysis. The catalysts were characterized by pulse chemisorption, temperature programmed reduction (TPD), scanning transmission electron microscopy (STEM), and X-ray photoelectron spectroscopy (XPS). The activity of the catalysts for methane combustion was measured in …

Coevolutionary Analysis Implicates Toll-Like Receptor 9 In Papillomavirus Restriction, Kelly King, Brendan B. Larsen, Sophie Gryseels, Cécile Richet, Simona Kraberger, Robert Jackson, Michael Worobey, Joseph S. Harrison, Arvind Varsani, Koenraad Van Doorslaer

Pacific Faculty Work

Upon infection, DNA viruses can be sensed by pattern recognition receptors (PRRs), leading to the activation of type I and III interferons to block infection. Therefore, viruses must inhibit these signaling pathways, avoid being detected, or both. Papillomavirus virions are trafficked from early endosomes to the Golgi apparatus and wait for the onset of mitosis to complete nuclear entry. This unique subcellular trafficking strategy avoids detection by cytoplasmic PRRs, a property that may contribute to the establishment of infection. However, as the capsid uncoats within acidic endosomal compartments, the viral DNA may be exposed to detection by Toll-like receptor 9 …

The Synthesis And Purification Methodology Of An Intermolecular Pyrophosphate Sensor: Applications For The Quantitative Polymerase Chain Reaction, Ethan Gevedon

Honors Projects

The optimized synthesis and purification methodology for an intermolecular pyrophosphate sensor scaffold molecule was performed: high performance liquid chromatography afforded the scaffold in excellent purity and yield. The applications of the sensor assembly in the quantitative polymerase chain reaction were discussed, and preliminary results show that

Collision-Induced Dissociation And Ion Mobility Mass Spectrometry Of Au30(S-Tbu)18 Nanoclusters, Christopher Hood

Honors Theses

Collision Induced Dissociation (CID) and Ion Mobility Mass Spectrometry (IM-MS) are methods used to understand the structural arrangement and stability of large molecules. In this study, the gold nanocluster Au₃₀(S-tBu)₁₈ was dissociated at varying Trap collision energies, and drift time vs mass spectrometry data was plotted to determine the order of cluster fragmentation. Comparing Au₃₀(S-tBu)₁₈ data to that of Au₂₅(SCH₂CH₂Ph)₁₈, the only current nanocluster published with IM-MS data, two distinctly different dissociation patterns were seen. Unlike the linear CID fragmentation of Au …

Synthesis And Characterization Of Alkyne-Functionalized Photo-Cross-Linkable Polyesters, Warrick Ma, Xiaochu Ding, Ying Chen, Yadong Wang

Michigan Tech Publications, Part 1

An alkyne-functionalized elastomer derived from sebacic acid, 1,3-propanediol, and alkyne-functionalized serinol is synthesized via melt condensation. A low-power UV lamp triggers the cross-linking rapidly via thiol-yne click chemistry. The cross-linking behavior is studied by photorheology and NMR spectroscopy. The resultant elastomer possesses mechanical properties similar to those of human soft tissues and exhibits in vitro degradability and good cytocompatibility.

Synthesis And Characterization Of Redox-Active Multidentate Ligands For Catalytic C-H Bond Oxidation And Carbon Dioxide Reduction, Caroline Hodge

Honors Theses

This thesis focuses on two research projects. The first project reported in Chapter 1 involves the synthesis and application of a tetradentate ligand (2-(1,1-di(pyridin-2-yl)ethyl)-1,10-phenanthroline, PhenPY2Me) that is metalated with iron to give a catalyst capable of carbon-hydrogen (C-H) bond oxidation. C-H bond oxidation provides a method that may allow some transformations in organic syntheses to be streamlined. The mononuclear iron complex supported by PhenPY2Me was found to dimerize in the presence of O₂ in a non-coordinating solvent. These iron complexes and a previously reported system were assessed and compared in C-H bond oxidation with model substrates using the sacrificial …

Targeting Platelets Using Ionic Liquid Coated Nanoparticles, Karen Mun Wong

Honors Theses

Platelets are key players in our body’s inflammatory processes upon activation, which can create physiological problems. Researchers are actively seeking solutions by targeting platelets with therapeutics. The objective of the research in this thesis was to investigate a new and potentially less invasive drug delivery platform using nanoparticles. The topic of the project was to explore the world of ionic liquids and their abilities, when coated on nanoparticles, to bind to platelets. A library of choline carboxylic acid-based ionic liquids (ILs) was first synthesized via salt metathesis while PLGA-based nanoparticles were simultaneously being synthesized via the nanoprecipitation method. The ionic …

The Phosphorus Problem In The Pre-Biotic World, Erica Bronwyn Mobley

ONU Student Research Colloquium

The so-called “phosphorus problem” in prebiotic life has traditionally been framed in terms of phosphate solubility. Phosphates (PO₄^3-) are generally insoluble and therefore cannot supply adequate nutrients for protocellular metabolism. Phosphite (HPO₃^2-) is thought to solve this problem, but introduces a new obstacle, what might be termed the “phosphorus permeability problem”. Phosphate and phosphite are both charged at circumneutral pH and cannot cross a lipid membrane. No evolutionary pressure exists to drive formation of transporters prior to the existence of a membrane, and so the first protocells likely lacked transporters. We suggest that volatile …

Evaluating The Impact Of River Settlement On Phosphorus Uptake, Erica Bronwyn Mobley

ONU Student Research Colloquium

Phosphorus sorption to sediments is an important process that can buffer dissolved P concentrations. Both the amount of P and sediment as well as the mode of binding can influence transport of P in aquatic ecosystems. This study focused on determining sediment stocks in the Maumee River basin and quantifying reactive and total P extracted from sediment by a sequential multi-step process. Quantification of sediment stock will enable more accurate modeling of P retention and ultimately P loading into western Lake Erie.

How Student Attitudes Have Changed Toward Chemistry Due To The Implementation Of Hybrid Labs, Erica Bronwyn Mobley

ONU Student Research Colloquium

Hybrid chemistry labs in schools and universities have become much more common due to the COVID-19 pandemic. Previous research on student perceptions of chemistry has shown a correlation between their attitudes and performance in this subject that educators are still seeking to understand. This mixed methods study compared perceptions of students in traditional, in-person labs (pre-COVID, 2017) with students in a mixture of virtual and in-person labs (during COVID, 2020) over the course of a semester. The Attitude toward the Study of Chemistry Inventory (ASCI) survey was given to both cohorts of students and focused on five areas related to …

Carbon-Carbon Bond Activation: Optimization Of Decarbonylation-Exchange Reactions Of Diortho-Fluoro Pyridyl Ketone With Boronic Acids, Therese A. Joffre, Luke J. Shoemaker, Eric A. Salisbury, Erik J. Schoonover, Jacob P. Vanderroest

21st Annual Celebration of Undergraduate Research and Creative Activity (2022)

Rhodium-catalyzed decarbonylation reactions have been shown to occur readily with a variety of substituted pyridyl ketones. However, the 2,6-diortho-fluoro pyridyl ketone does not undergo decarbonylation on its own. When testing the unreactive ketone, a reaction was found with boronic acids that leads to an aryl ring exchange and subsequent decarbonylation. This decarbonylation-exchange reaction was further optimized by evaluating three promising sets of experimental conditions. The 2,6-diortho-fluoro ketone was reacted with a series of boronic acids to assess the scope of this transformation using these sets of experimental conditions.

Landscape Materials: Impact On Water Quality At Different Temperatures, Vignesh Tiruvannamalai '24

Distinguished Student Work

The purpose of this experiment is to analyze how commonly used landscaping materials (wood mulch, rubber mulch, and landscape stones) will affect the quality and chemical composition of runoff water they come into contact with, and how this will be impacted by different temperatures experienced in different climatic regions.

In order to conduct this experiment, always wear safety goggles and gloves when handling experiment materials. First, prepare the landscaping materials and rinse the containers and lids. Then, place the designated amount of landscaping materials in each container and fill each with 2.27 liters of filtered water, subsequently covering them and …

Towards Asymmetric Mannich Reactions And Alkylation Of Indoles, Bianco Bicalho

Honors Theses

In the presence of trimethylsilyl trifluoromethanesulfonate (TMSOTf) and 2,6-lutidine, acylated thiones undergo Aldol and Mannich reactions with aldehydes and nitrones to yield complex nitrogen-containing compounds. The use of a chiral metal-ligand complex is hypothesized to accelerate the reaction and increase stereochemical control during product formation. N-Alkylindoles undergo Friedel-Crafts alkylation with acetates in the presence of TMSOTf and 2,6-lutidine to produce 3-alkyl indoles. Varying Substitution on the indole at the 5 position and removal of the alkyl group from the 1 position both show continued reactivity at the 3 position even in the presence of TMSOTf.

Simplified Synthesis Of Conjugated Polymers Enabled Via 1,4-Dihydropyrrolo[3,2-B]Pyrrole, Kenneth-John Jack Bell

Master of Science in Chemical Sciences Theses

Conjugated polymers have attracted significant attention as the active layer material in organic electronics, such as organic photovoltaics and light-emitting diodes, partly due to the ability to influence a broad range of properties through structural design motifs. However, high performance conjugated polymers suffer from numerous synthetic steps, generation of toxic waste, and harsh reaction conditions all of which impart additional costs that inhibit their widespread utilization. Therefore, an emphasis on reducing synthetic complexity and utilizing abundant, commercially available starting materials is needed for organic electronics to reach their full potential. Dihydropyrrolo[3,2-b]pyrrole (H₂DPP) chromophores offer a simple one-pot synthesis …

Binary Transition Metal Oxides@Reduced Graphene Oxide@Polyaniline As Bifunctional Electrode Materials For Energy Conversion And Storage, Jonghyun Choi

Electronic Theses & Dissertations

The world’s increasing consumption of energy has led researchers to focus on research and development for high performance-energy devices. Development of materials used in energy devices is currently focused on improving the performance and stability of devices. Composite materials are well known as an effective way to improve the performance of an energy device. A composite is a combination of two or more materials with different properties, and such combinations can be of great help in advancing the performance of a composite material by adding the advantages or compensating for the disadvantages of each material.

In this study, ternary composite …

Synthesis Of Benzophenone-O-Glycosides Under Basic Conditions, Samuel Burns

Undergraduate Research Symposium 2022

Type 2 diabetes is a growing health concern worldwide characterized by high blood sugar. Anti-diabetic therapy aims at correcting this sugar imbalance by inhibiting the enzyme α-glucosidase which is responsible for cleaving carbohydrates and starch into glucose. Benzophenone glycosides are a class of biomolecules with α-glucosidase inhibitory properties that have garnered some attention. It can be found and isolated from some traditional medicinal plants which was not done for this project. Once isolated, new derivatives can be synthesized by manipulating protecting groups of the starting material to get the benzophenone. The benzophenone can then undergo glycosylation with the protected sugar …

Fast Photochemical Oxidation And Footprinting Of Proteins Via Trifluoromethyl Radical Chemistry, Elaine Morrow

Honors Theses

Fast photochemical oxidation of proteins (FPOP) is a useful tool in proteomics because of the ability for modifications to occur on the scale of microseconds which reduces the modifications to tertiary and quaternary structure allowing for more accurate labeling of the protein. Labels for FPOP are generated from various radicals in our experiments which include hydroxyl radicals and trifluoromethyl radicals. Hydroxyl radicals are easily generated by using an excimer laser (KrF laser, 248 nm) or a UV flash lamp (as a part of the Fox™ System) by the photolysis of hydrogen peroxide. Trifluoromethyl radicals, however, need hydroxyl radicals to be …

Interactions Of Tug-Ubl1 And Insulin And Implications For Glucose Uptake, Megan Kohout

Celebrating Scholarship and Creativity Day (2018-)

TUG-UBL1 (Tether Containing UBX Domain for GLUT-4 Ubiquitin Like 1) is a glucose transporter 4 (GLUT4) regulating protein which facilitates the release of GLUT4 transport vesicles when insulin stimulation is present. To understand the role of TUG-UBL1 in glucose metabolism, especially for type two diabetic patients for whom increases in insulin concentration do not correlate with increased glucose uptake, we explored the research question of whether TUG-UBL1 binds to insulin. Initially, models of full-length TUG-UBL1 (amino acids 1-473), the GLUT4 binding domain of TUG-UBL1 (amino acids 86-337), and the insulin heterodimer were built using PHYRE2. All of these structures were …

The Effects Of Paclitaxel On Cellular Migration And The Cytoskeleton, Ashley Salguero-Gonzalez

Thinking Matters Symposium

In a clinical setting, some patients are exposed to an anti-cancer chemotherapy agent, paclitaxel. Cancerous cells undergo rapid, continuous cell division without control. Chemotherapy treatments try to slow and stop the uncontrollable cell division cycles and eliminate cancerous cells in the process. Paclitaxel serves as a treatment for some types of cancers, including lung, melanoma, bladder, and esophageal. Because it targets the cytoskeleton, paclitaxel can also influence cell migration. This project utilizes a cellular migration assay and an immunohistochemistry assay to analyze the effects of paclitaxel on the movement of cells and on the cytoskeleton of neuroglia rat cells with …

Designing Experiments: The Impact Of Peer Review Structure On Organic Chemistry Students' Experimental Designs, Katie Patterson

Department of Chemistry: Dissertations, Theses, and Student Research

To better understand how peer review can be used to support students when designing experiments, the current thesis examined how the structure of the peer review template affects the kinds of feedback students give and the revisions that they make. I utilized a quasi-experimental design to investigate the effects that the peer review template had on the outcome of an experimental design task. A sample of 195 students enrolled in an Organic Chemistry I course participated in the study. The students were divided into two groups, one of which was given a scaffolded peer review template and the other was …

Volume 13, Payton Davenport, Audrey Lemons, Jacob Shope, Haley Smith, Cassandra Poole, Rachel Cannon, Rachel Boch, Suzanne Stetson

Incite: The Journal of Undergraduate Scholarship

Introduction Dr. Roger A. Byrne, Dean

From the Editor Dr. Larissa “Kat” Tracy

From the Designers Rachel English, Rachel Hanson

The Effect of Compliment Type on the Estimated Value of the Compliment by Payton Davenport, Audrey Lemons, and Jacob Shope

The Imperial Japanese Military: A New Identity in the Twentieth Century, 1853–1922 by Haley Smith

Longwood University’s campus: Human-cultivated Soil has Higher Microbial Diversity than Soil Collected from Wild Sites by Cassandra Poole

Reminiscent Modernism: Poetry Magazine’s Modernist Nostalgia for the Past by Rachel Cannon

Challenges Faced by Healthcare Workers During the COVID-19 Pandemic: A Preliminary Study of Age and …

X-Ray Crystallographic Analysis Of Quinoline N-Oxide And Isoquinoline N-Oxide With Zinc Halides, Nitrates, Perchlorates., Erin N. Groneck

GS4 Student Scholars Symposium

We have worked to analyze the chemistry between aromatic N-oxides, Quinoline N-oxide and Isoquinoline N-oxide, with zinc halides, nitrates, and perchlorates by X-ray crystallography. These structures were formed by reaction of the aromatic N-oxides with an equivalent of the zinc halide, nitrate, or perchlorate. These N-oxides had been chosen due to being the focus of this study. We will present the crystallographic X-ray structures of the synthesized novel complexes of the N-oxides with either a zinc halide, zinc nitrate, and zinc perchlorate.

Raman Spectroscopic And Quantum Chemical Investigation Of The Pyridine-Borane Complex And The Effects Of Dative Bonding On The Normal Modes Of Pyridine, Ethan C. Lambert, Benjamin W. Stratton, Nathan I. Hammer

Faculty and Student Publications

The pyridine-borane (PyBH3) complex was analyzed by Raman vibrational spectroscopy and density functional theory to elucidate its structural and vibrational properties and to compare these with those for neat pyridine (Py). The borane-nitrogen (BN) bond length, the BN dative bond stretching frequency, and the effects of dative-bonded complex formation on Py are presented. Rather than having a single isolated stretching motion, the complex exhibits multiple BN dative bond stretches that are coupled to Py's vibrations. These modes exhibit large shifts that are higher in energy relative to neat Py, similar to previous observations of Py/water mixtures. However, significantly higher charge …

New Synthetic Reactions Enabled By Protected Oxyallyl And Amidoallyl Cations, Binod Nepal

LSU Doctoral Dissertations

This dissertation entails design and development of two new synthetic methodologies made possible through the generation of cationic species, namely oxyallyl and amidoallyl cations. Chapter 1 involves literature survey on generation and trapping of oxyallyl cations. Mostly known for cycloaddition reactions with these elusive species, the most recent approach of direct nucleophilic capture of oxyallyl cations are discussed. Apt design of substrates and reaction conditions by Kartika Group to access a-electrophilic carbon towards the synthesis of a variety of value-added compounds, i.e., 1,4- and 1,6-dicarbonyls, carbazoles, densely substituted pyrroles and furans are elaborated.

Chapter 2 focuses on our discovery of …

Synthesis And Characterization Of A Novel Reaction-Based Azaborine Fluorescent Probe Capable Of Selectively Detect Carbon Monoxide Based On Palladium-Mediated Carbonylation Chemistry, Samuel Moore, Carl Jacky Saint-Louis

Symposium of Student Scholars

Azaborines are fascinating compounds because they possess valuable properties such as photochemical stability, have high molar absorption coefficient and high fluorescent quantum yields, as well as large Stokes shifts and tunable absorption/emission spectra. Here, we designed, synthesized, and will examine a novel reaction-based azaborine fluorescent probe capable of selectively detect carbon monoxide (CO) based on palladium-mediated carbonylation chemistry. This novel azaborine fluorescent probe will exhibit high selectivity for CO and display a robust turn-on fluorescent response in the presence of CO in aqueous buffer solution.