Chemistry Commons^™

Refinement Of A Thermodynamic Model To Explain The Weathering Patterns Of Ignitable Liquids On Household Substrates At Elevated Temperatures, Chaney Ashlyn Ganninger

Graduate Theses, Dissertations, and Problem Reports (ETD)

ABSTRACT

Refinement of a thermodynamic model to explain the weathering patterns of ignitable liquids on household substrates at elevated temperatures

Chaney A. Ganninger

In 2021, arson caused more than 4,361 deaths in the United States. To aid in the differentiation between arson and accidental or natural causes, investigators often analyze fire debris for the presence of ignitable liquid residues using headspace concentration followed by gas chromatography-mass spectrometry (GC-MS). Classification of ignitable liquids can be confounded by weathering, which is the uneven evaporation of compounds in ignitable liquid residues. The Jackson group, among others, has developed a thermodynamic model to help …

Expanding The Vibrating Sharp-Edge Spray Ionization Toolkit For Oligonucleotide Characterization, Sultan Mahmud

Graduate Theses, Dissertations, and Problem Reports (ETD)

A gentle or soft Ionization process is a critical component in native mass spectrometry (MS) to lift the biomolecules from the bulk solution into the gas phase environment of the mass spectrometer preserving their shape, topology and non-covalent interactions. Electrospray ionization (ESI) facilitates structural preservation of proteins, nucleic acids and their complexes and as a result it has been extensively used in native MS. However, in negative ion mode, ESI is somewhat limited in sensitivity due to corona discharge effect resulting from the requirement of a high amount of voltage. This often disrupts the ESI process and may not preserve …

Forensic Characterization And Comparison Of Modern Nail Polish Products By Their Physical Features And Chemical Composition, Madison Meredith Lindung

Graduate Theses, Dissertations, and Problem Reports (ETD)

Nail polish can serve as valuable evidence in forensic investigations as it is often found on the hands and feet of individuals. Nail polish can break off and transfer easily during self-defense actions or forceful contact, such as in cases of kidnapping, sexual assault, or homicide. These residues can provide clues about who was at the scene, as well as where, when, and how the event evolved. However, compared to other types of paints commonly analyzed in forensic laboratories, limited forensic research has been conducted on the chemical composition and discrimination capabilities of popular nail products. The lack of information …

Introduction Of Polar Functional Groups To Pyridinedipyrrolide Zirconium Photosensitizers Through Post-Synthetic Modifications, Marisa Nicole Tordella

Graduate Theses, Dissertations, and Problem Reports (ETD)

Photosensitizers are vital components to applications such as photoredox catalysis, photodynamic therapy, and various avenues of solar energy production. The abilities of transition metal photosensitizers containing precious metals have been well studied over the years. However, because of the growing scarcity of these metals, there has been a shift in finding more earth abundant alternatives. To help fill this gap in the literature, the Milsmann group has developed and studied the photophysical properties of Zr(IV) complexes with various ligand systems. Due to the electron deficient metal center, these complexes exhibit ligand-to-metal charge transfer (LMCT), unlike the metal-to-ligand charge transfer commonly …

Effects Of Chain Length, Saturation, And Bases On Saponification, Sarah Fenik

Williams Honors College, Honors Research Projects

This project will analyze the effects of chain length and saturation of fatty acids on saponification processes, as well as the effects of the base used in the reaction. Stearic acid, lauric acid, and oleic acid will be used for the fatty acid comparisons, and sodium hydroxide and potassium hydroxide will be used for the base comparisons. Stearic acid is considered a long chain fatty acid, while lauric acid is considered a short chain fatty acid. Oleic acid is a monounsaturated fatty acid. Five soap products are be made: sodium stearate, sodium laurate, sodium oleate, potassium stearate, and potassium oleate. …

Cold Atmospheric Plasma Induced Degradation Of Organophosphate Pesticides On Kevlar Swatches, Ta Chun Lin, Victor Somtochukwu Mbanugo, Boluwatife Stephen Ojo, Yue-Wern Huang, Marek Locmelis, Frank Daoru Han

Biological Sciences Faculty Research & Creative Works

Cold atmospheric plasma (CAP) was evaluated for degrading organophosphate pesticide (OP) residues (acephate, malathion, and dimethoate) from Kevlar fabrics. Fourier transform-Infrared (FTIR) spectroscopy, scanning electron microscope (SEM) imaging and tensile strength testing confirmed that CAP treatment preserved Kevlar's structural integrity and mechanical properties. Results show degradation efficiency increased with higher power, shorter discharge gaps, and longer exposure duration. Hyperspectral imaging supported the detection of plasma-induced spectral changes, reinforcing the presence of reactive species. The strong oxidative potential of CAP facilitated the rapid breakdown of OPs into nontoxic byproducts. These findings demonstrate the potential of CAP as a portable, energy-efficient solution …

Metal-Free Photoredox Catalysis For The S-Trifluoromethylation Of Thiols, Raheemat Rafiu, Puspa Aryal, V. Prakash Reddy

Chemistry Faculty Research & Creative Works

The S-trifluoromethylation of thiols is accomplished using a simple and cost-effective organic catalyst (diacetyl) along with a bench-stable and environmentally friendly trifluoro methylating reagent (Langloi's reagent). Under optimized conditions (2.5 equivalents of Langlois reagent, Blue LED irradiation, 48-h reaction time at room temperature), the reaction yielded up to 81% S-trifluoro methylated product. This method's high yields, compatibility with a broad substrate scope (aliphatic, heteroaromatic, and aromatic thiols), and environmentally friendly conditions demonstrate its potential for broader synthetic applications. In contrast to traditional methods that rely on organometallic catalysts and environmentally hazardous reagents, this novel photoredox catalysis method offers a more …

Characterizing The Transient Emission Of Particles And Gases From A Single Puff Of Electronic Cigarette Smoke, Kashala Fabrice Kapiamba, Steven Achterberg, Ta Chun Lin, Philip D. Whitefield, Yue-Wern Huang, Yang Wang

Chemistry Faculty Research & Creative Works

This study employed high-time-resolution systems to examine the transient properties of aerosols and gases emitted from electronic cigarette (EC) puffs. Using a fast aerosol sizer, we measured particle size distributions (PSDs) across various EC brands (JUUL, VUSE, VOOPOO), revealing sizes ranging from 5 to 1000 nm at concentrations of 107 to 1010 cm-3. Most aerosols were found to be in the ultrafine range (below 100 nm), with JUUL-, VUSE-, and VOOPOO-producing aerosols with geometric mean sizes of 19.9, 47.3, and 29.4 nm, respectively. Applying the International Commission on Radiological Protection (ICRP) deposition model and assuming no further evolution of aerosols …

Formation Of Hydrocarbons And Carbon Oxides In Mxene Reactions With Water Under Varying Oxidative Conditions, Shuohan Huang, Guanglei Xiang, Vadym Mochalin

Chemistry Faculty Research & Creative Works

Titanium carbide / carbonitride MXenes have garnered significant attention due to their remarkable properties, versatile solution processability, and broad range of potential applications. However, when exposed to the environment, MXenes are susceptible to degradation, which ultimately leads to the formation of metal oxides, a process that may be regarded as either disadvantageous or beneficial, depending on the application of a MXene and our knowledge about the underlying mechanisms. Therefore, it is very important to understand the reactivity of MXenes in different environments and conditions. Although researchers have made efforts to understand MXene degradation in air and water, our knowledge of …

Instantaneous Hydrolysis Of Methyl Paraoxon Nerve Agent Simulant Is Catalyzed By Nontoxic Aminoguanidine Imines, Emmanuel Kingsley Darkwah, Puspa Aryal, Chi Zhang, Charles B. Musgrave, William A. Goddard, V. Prakash Reddy

Chemistry Faculty Research & Creative Works

Exposure to organophosphate-based nerve agents and pesticides poses health and security threats to civilians, soldiers, and first responders. Thus, there is a need to develop effective decontamination agents that are nonhazardous to human health. To address this, we demonstrate that instantaneous hydrolysis of methyl paraoxon (Me-POX), a nerve agent simulant, can be achieved in the presence of aminoguanidine imines at pH 10: ● the pyridine-4-aldehyde aminoguanidine-imine (1) and ● the 2,3-butanedione aminoguanidine-imine (2). The hydrolysis of Me-POX under these conditions is substantially faster than that of the state-of-the-art decontaminating agent, Dekon-139 (2,3-butanedione oxime, potassium salt). Furthermore, Dekon-139 shows adverse effects …

Synthesis And Characterization Of Free Radical Scavenging Dendrimer Nanogels Via Cross-Linking Reaction-Enabled Flash Nanoprecipitation, Lin Qi, Da Huang, Huari Kou, Anna Chernatynskaya, Nuran Ercal, Hu Yang

Chemistry Faculty Research & Creative Works

This work reports the development and evaluation of dendrimer-based nanogels based on Poly amidoamine (PAMAM) dendrimer generation 5, engineered to act as a carrier with reactive oxygen species (ROS)-scavenging capabilities. We developed a cross-linking reaction-enabled flash nanoprecipitation method in which the cross-linking reaction occurs during the flash nanoprecipitation process to form a cross-linked nanostructure. Using this approach, an N-hydroxy succinimide (NHS)-functionalized ROS-responsive thioketal cross-linker (TK-NHS) was synthesized and utilized to cross-link DAB-core PAMAM dendrimer G5, resulting in the formation of G5-TK nanogels. The resulting nanogels were characterized using dynamic light scattering and transmission electron microscopy, and their cytocompatibility, irritancy, cellular …

Pla-Based Bone Tissue Engineering Scaffolds Incorporating Hydroxyapatite And Bioactive Glass Using Digital Light Processing, Engin Gepek, Fateme Fayyazbakhsh, Lev Suliandziga, Vadym Mochalin, Osman Iyibilgin, Yue-Wern Huang, Ming C. Leu

Chemistry Faculty Research & Creative Works

Bone tissue engineering (BTE) aims to repair bone defects using biocompatible materials with tailored geometries and pore structures, providing appropriate mechanical support and control over biodegradation kinetics to promote bone growth. In this study, we utilized digital light processing (DLP) 3D printing to fabricate scaffolds with varying pore sizes using polymer–ceramic slurries composed of polylactic acid (PLA) as the main polymer matrix, incorporated with hydroxyapatite (HA) and bioactive borate glass (BBG) at various ratios. We studied the effect of composition on rheological behavior, printability, mechanical properties, bioactivity, degradation rate, and biocompatibility. While HA increased viscosity and reduced printing accuracy, it …

Unveiling Pseudocapacitance: A Kinetic Treatment Of The Pseudocapacitive Biosensor, Rokas Gerulskis, Egor Baiarashov, Maryam Karimi, Wassim El Housseini, Shelley D. Minteer

Chemistry Faculty Research & Creative Works

A kinetic framework is introduced for a pseudocapacitive potentiometric biosensor. Mathematical derivation and kinetic modeling demonstrate that experimentally observed linearity in analyte-OCP response arises from a dynamic equilibrium between competing redox reactions on a single electrode. This system can be expanded to develop a new generation of biosensors.

Mechanical And Thermal Characterization Of Additively Manufactured Carbon/Nylon 12 And Carbon/Peek Composites, Matik Heskin, Bradley Deuser, Thomas P. Schuman, K. Chandrashekhara, John Bayldon, Jeff Degrange, Steven Patterson, Neiko Levenhagen

Chemistry Faculty Research & Creative Works

This study explores additive manufacturing of carbon fiber-reinforced thermoplastic composites using the Composite-Based Additive Manufacturing (CBAM) process. Carbon/Nylon 12 and Carbon/PEEK composites were fabricated and evaluated through mechanical (compression, tensile, flexural, and impact) and thermal (DSC and TGA) tests. Carbon/PEEK exhibited superior mechanical performance, with 97.5% higher tensile strength, 79.8% higher elastic modulus, and 59.6% higher flexural strength compared to Carbon/Nylon 12. Thermal testing showed that Carbon/PEEK had higher thermal stability, beginning degradation at 350 °C versus 298 °C for Carbon/Nylon. These results indicate that CBAM-fabricated Carbon/PEEK composites are suitable for applications requiring high strength and temperature resistance.

Electrochemically Active Molybdenum Phosphate With Open-Framework Structure, Sutapa Bhattacharya, Milad Aghayi-Anaraki, Nikolay Gerasimchuk, Steven P. Kelley, Amitava Choudhury

Chemistry Faculty Research & Creative Works

Somewhat less investigated, lithium ion containing molybdenum phosphate compounds are synthesized via simple template free hydrothermal method. Single-crystal X-ray diffraction (SCXRD) study reveals that the compounds Li_0.89Mo₂O_1.89F_0.11(PO₄)2(H₂PO₄)·xH₂O (x ≈1) and Li₃Mo₂O₂(PO₄)₃·xH₂O (x ≈1) crystallize in monoclinic C2/m and C2/c space group, respectively. The structures are built of alternate corner-sharing of MoO₆ octahedra and PO₄ tetrahedra forming layers, which are pillared by phosphate groups creating a 3D framework with channels. These …

Atomistic Mechanisms Of Ti3alc2 Etching: Oxidation, Surface Stability, And Selectivity, Valentina Nesterova, Ana Maria Stratulat, Walter Malone, Vadym Mochalin, Majid Beidaghi, Konstantin Klyukin

Chemistry Faculty Research & Creative Works

Mechanisms governing MAX-phase etching set the properties and stability of resulting MXenes, yet the details of this complex process remain poorly understood. Combining thermodynamic analysis of surface chemistries with ab initio molecular dynamics and enhanced free-energy sampling, we directly model elementary steps at the MAX/etching solution interface. We find that purely thermodynamic analysis overestimates etching selectivity, which is governed by the kinetics of elementary reaction steps. Our calculations reveal that initial exposure to water drives localized, thermodynamically favored edge oxidation that seeds MXene-like terminations into the uppermost layers of Ti₃AlC₂ with oxygen occupying the interlayer space between …

Cloud Condensation Nuclei Activity Of Fresh And Aged Phenolic Acid Aerosol Particles, Emily A. Nortmann

Honors Undergraduate Theses

In recent years, the incidence of wildfires has considerably increased, with fire seasons starting earlier and ending later than usual due to changes in snowpack, precipitation, and temperature, which are attributed in part to climate change. Wildfires are responsible for the emission of a variety of gases and organic aerosol particles in the atmosphere with profound impacts on air quality, visibility, and human health. The aerosol particles produced by wildfires can contribute to climate change by scattering or absorbing solar radiation, affecting the radiative balance of the planet through cooling or warming effects, or by acting as cloud condensation nuclei …

Synthesis Of Novel Schiff Bases And Their Metal Complexes, Ryan J. Lukkarinen

Theses and Dissertations

Presented in this thesis is the synthesis and characterization of multiple thiosemicarbazones and dithiocarbazates, as well as their corresponding metal complexes. Chapter 1 is an introductory chapter exploring the significance and potential applications of this work. Chapter 2 focuses on thiosemicarbazone synthesis and characterization. Chapter 3 describes the synthesis and characterization of dithiocarbazates. Chapter 4 details metal complex synthesis using the previously described ligands. Chapter 5 summarizes the conclusions of the research and future work that may stem from it.

High Throughput, Solid Sample Analysis With Cone-Based Mass Spectrometric Ionization Sources, Emily J. Wiggins

Theses and Dissertations

The widespread presence of environmental and consumer-product contaminants (e.g. trace metals, opium alkaloids) has underscored the need for rapid, reliable, and high-throughput analytical techniques that are capable of handling complex solid samples. While traditional mass spectrometric (MS) methods tend to have high sensitivity and accuracy, they often require labor-intensive and time-consuming sample preparation steps that limit throughput and field applicability. This thesis investigates the use of 3D-Printed Cone Spray Ionization-Mass Spectrometry (3D-PCSI-MS) as an ambient ionization technique for the direct screening of contaminants from solid matrices, eliminating the need for traditional sample preparation and allowing for real-time analysis.

In …

Thermo-Rheological And Tribological Properties Of Low- And High-Oleic Vegetable Oils As Sustainable Bio-Based Lubricants, Abiodun Saka, Tobechukwu K. Abor, Anthony C. Okafor, Monday U. Okoronkwo

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Vegetable oil-based lubricants have attracted increased research attention in recent decades as sustainable alternatives to conventional petroleum-based lubricants in metal machining. However, more studies are required to fully elucidate the thermo-rheological and tribological properties. This study presents an investigation of the thermo-rheological and tribological properties of different vegetable oils, including low- and high-oleic soybean oil, high-oleic sunflower, safflower, and canola oils. The lubricity, and evolution of viscosity and thermodynamic properties as a function of temperature were investigated to obtain important parameters including the viscosity index, flow behavior index, flow activation energy, specific heat capacity, thermal conductivity, coefficient of friction, contact …

Approaches To The Synthesis Of Highly Substituted Arenes, Kh Tanvir Ahmed

Graduate Theses, Dissertations, and Problem Reports (ETD)

While benzene rings and their derivatives are among the most frequently encountered ring systems in natural products, pharmaceuticals, agrochemicals, dyes, and functional materials, polysubstituted arenes are relatively scarce. The analysis of FDA-approved small molecules provides valuable insights into the characteristics of successful drugs while also highlighting gaps in the availability of synthetic methods capable of efficiently accessing diverse substitution patterns on aromatic rings. Highly substituted arenes are typically synthesized through sequential modification of a pre-existing benzene core; however, this stepwise approach becomes increasingly challenging with each additional substitution. An alternative strategy involves the direct construction of benzene rings via annulation …

Free Energy Approaches To Understanding The Mechanism Of Membrane-Active Peptides, Hannah R. Scott

Graduate Theses, Dissertations, and Problem Reports (ETD)

Cancer is a leading cause of death in the world today. Current methods of treatment fail to distinguish the difference between cancer cells and cells of healthy tissue, leading to off-target effects, often with terminal outcomes. A potential solution to this challenge is to target the cancer cells’ microenvironment. One universal characteristic across all cancer cells is the acidic extracellular environment. The pH-Low Insertion Peptide (pHLIP) is a membrane-active peptide with acid-sensitive function, undergoing folding and insertion into a transmembrane alpha-helix. pHLIP is a promising candidate to be used to deliver anti-cancer agents exclusively to cancer cells. Although the mechanism …

Assessment Of Analytical Workflows Of Gunshot Residue Evidence And Strategies For Implementation Of Advanced Technology In Crime Laboratories., Leah D. Thomas

Graduate Theses, Dissertations, and Problem Reports (ETD)

The rise in gun violence in the United States has increased the demand on forensic agencies to process evidence promptly and accurately. The exchange of imperceptible traces among objects, suspects, and victims can provide critical insights into the interactions and sequence of events during a crime. Gunshot residue (GSR) is a type of trace evidence that holds significant investigative value in shooting reconstructions. GSR can help identify potential shooters, intermediate targets, and bullet trajectories; however, its analysis is often expensive and time-consuming. Consequently, there is an urgent need for more effective solutions.

Methods for on-site screening can significantly streamline forensic …

Investigation Of Protein-Ligand Binding Interactions Through The Computational Methods Of Molecular Dynamics And Graph Neural Networks, Alexander Benjamin Wroe

Graduate Theses, Dissertations, and Problem Reports (ETD)

Studies in protein ligand binding are a significant focus in the field of medicinal chemistry

and biochemistry, facilitating a greater understanding of the structure-function relationship

of the protein and controlling function via drug development. In this research, we identify

new binding sites for lipids on the microbial membrane protein, proteorhodopsin, and apply

machine learning approaches to accelerate the generation of binding affinity-like data for the

use in the identification of potential small molecule drugs. The platelet activating factor

receptor. Cardiolipin, a lipid in membranes, and proteorhodopsin, a microbial proton pump,

are both commonly found in microbial membranes, but little is …

Development And Applications Of Capillary Vibrating Sharp-Edge Spray Ionization Coupled With Atmospheric Pressure Chemical Ionization (Cvssi-Apci), Madison Elizabeth Pursell

Graduate Theses, Dissertations, and Problem Reports (ETD)

Mass spectrometry (MS) is a technique that is used in fields in which both complex and non-complex mixtures are analyzed. The state-of-the-art ion sources that are utilized for MS are being demonstrated to be functional for direct infusion of samples as well as for use with online separations. However, ion sources, such as electrospray ionization (ESI) and atmospheric pressure chemical ionization (APCI) can encounter problems such as ion suppression and an inability to ionize based on size and/or polarity, respectively. Further these sources are bulky and require gas flow, heat sources, and additional high voltage power supplies for optimal performance. …

Rational Design Of Small Molecules Targeting Mitochondrial Redox Proteins, Matheus Barbosa Belchior

Graduate Theses, Dissertations, and Problem Reports (ETD)

Reactive oxygen species play a crucial role in many cellular processes. Despite being a natural byproduct of cellular metabolism, overexpression of these species causes damage to the cell, leading to cell dysfunction. Central to the regulation of these highly reactive molecule is the mitochondria. Impairment in its function has been associated with oxidative stress within the cell. Herein, a ligand-based and structure-based approach to design new small molecules to inhibit mitochondrial redox proteins associated with oxidative stress and reactive oxygen species. In the first project two molecules were synthesized and characterized as potential monoamine oxidase B inhibitors. Results showed two …

Development Of Fast And Comprehensive Approaches For Gunshot Residue Interpretation Using Ambient Ionization, Mass Spectrometry, And Microparticle Sampling Studies, Thomas Dimmey Ledergerber

Graduate Theses, Dissertations, and Problem Reports (ETD)

The information derived from the forensic examination of gunshot residue (GSR) can be critical during the investigative and trial stages in the criminal justice system. However, the complexity of the GSR deposition, transfer, and persistence mechanisms calls for meticulous handling and identification processes. Novel advances in evidence interpretation and analysis via instrumental methods are current areas of growing interest that must be pushed along the chain from research to practice in a timely manner. Therefore, this research focuses on developing both rapid and comprehensive methods for detecting gunshot residue evidence and effectively communicating its significance to the investigators or trier …

3d Printed Microfluidic Platforms For Elisa-Based Diagnostics: Advancing Toward Point Of Care, Brandi Marie Binkley

Graduate Theses, Dissertations, and Problem Reports (ETD)

Protein biomarker detection is a critical analytical method for quantifying proteins in biological samples. It is relevant not only in medical diagnostics and research but also numerous other fields such as environmental monitoring, pharmacology, food safety, and biotechnology. Sensitive detection at picogram-per-milliliter (pg/mL) levels is essential for diagnosing diseases, monitoring progression, and tailoring treatments, especially for low-abundance biomarkers like troponin, interleukin 6, carcinoembryonic antigen (CEA), activin A, and vascular endothelial growth factor (VEGF). Immunoassays, particularly enzyme-linked immunosorbent assays (ELISAs), are the gold standard for protein biomarker detection due to their high specificity and sensitivity. The development of point-of-care (POC) diagnostic …

Developing Consensus-Based Methods For The Examination And Interpretation Of Contemporary Vehicle, Architectural, And Portable Electronic Device Glasses By Micro-X-Ray Fluorescence Spectrometry, Zachary Bailey Andrews

Graduate Theses, Dissertations, and Problem Reports (ETD)

Glass is a trace material that is commonly encountered during investigations of violent crimes. When glass is recovered at crime scenes, it can be used to establish links between suspects, victims, and the scene itself. The most discriminatory form of analysis for glass evidence is elemental analysis, and micro-X-ray fluorescence spectrometry (µXRF) is becoming an increasingly common technique used for this purpose. Recent advances in µXRF technology, such as the introduction of silicon drift detectors (SDD) and improved polycapillary optics are promising in enhancing the capabilities for the examination of glass evidence in forensic investigations. However, along with these advances …

Functionalized Carbon Nanohoops: Synthesis, Structural Insights, And Pathways To Carbon Nanobelts, Liu Li

Graduate Theses, Dissertations, and Problem Reports (ETD)

The development of structurally defined carbon nanostructures has gained significant attention due to their unique electronic, optical, and mechanical properties. Cycloparaphenylenes (CPPs), also known as carbon nanohoops, and carbon nanobelts (CNBs) represent key molecular segments of carbon nanotubes (CNTs), offering a bottom-up approach to precise nanotube construction. This dissertation focuses on the synthesis, structural characterization, and functionalization of CPPs, as well as the development of novel synthetic pathways for CNBs. A series of functionalized CPPs, including [9]-, [12]-, [15]-, and [18]CPPs, were synthesized using a modular approach involving a Diels-Alder adduct formation followed by a Ni(cod)2/bpymediated macrocyclization reaction. The influence …