Chemistry Commons^™

Integration Of Fundamental Research And Cer: The Role Of Authenticity In Developing Views On The Nature Of Teaching, Learning, And Doing Science, Julie Donnelly

Electronic Theses and Dissertations

This dissertation is an integration of fundamental research and chemical education. It begins with two nonlinear spectroscopic studies of compounds important to the study of brain chemistry. In Chapter 2, we present a novel method using quantum mechanics for modelling ligand docking and the potential of nonlinear circular dichroism for elucidating the mechanism of cannabinoids docking to their receptor, a contribution to studies of varying psychological effects of cannabinoids. Considering existent challenges with measuring this phenomenon, in Chapter 3, we evaluate two-photon absorption properties of Thioflavin T (ThT) in varying glycerol/water content solutions and discuss the enhancement of nonlinear absorption …

Nanoscale Characterization And Mechanism Of Electroless Deposition Of Silver Metal, Christopher Grabill

Electronic Theses and Dissertations

This dissertation is an investigation of the nanoscale characteristics and mechanism of electrolessly deposited silver metal seeded by gold nanoparticles. The process of growing seed-nanoparticles on a polymer surface was studied. Several bifunctional amines and organic reducing agents were used to explore how these chemical factors affect the size and distribution of gold nanoparticles formed at the interface. The nanoparticles were characterized by transmission electron microscopy (TEM) and high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM). An electroless deposition (ED) bath developed by Danscher was selected to study electroless deposition of silver in detail. The chemical species in the bath …

Split Aptameric Turn-On Fluorescence Sensor For Detection Of Sequence Specific Nucleic Acid At Ambient Temperature, Nanami Kikuchi

Electronic Theses and Dissertations

Nucleic acid amplification tests (NAATs) enable sensitive detection of low density infections that microscopy and rapid diagnostic test are not capable of detecting. They enable quantitative and qualitative nucleic acid detection, genotype analysis, and single nucleotide polymorphism (SNP) detection. Current state of the art molecular probes used with NAATs includes molecular beacon (MB), Taqman and its variations. This work presents novel molecular probe designed from Spinach and Dapoxyl aptamers. The aptamers are split into two parts (split aptamer), allowing greater sensitivity and selectivity towards fully complementary nucleic acid analyte. The major advantage of split aptamer probe over state-of-the-art fluorescent probes …

The Forensic Characterization Of Bacterial And Fungal Organisms In Traditional Chinese Medicine, Julia Grzymkowski, Christopher J. Ehrhardt, Justin L. Poklis, Michelle R. Peace

Undergraduate Research Posters

There has been an increase in use of Traditional Chinese Medicine (TCM) in the United States because they are less expensive and believed to be more effective with less adverse effects in comparison to traditional pharmaceutics. Therefore, sales have increased in the US, despite articles and case studies demonstrating the dangers, such as injury and death, related to TCM, stemming from improper labelling, toxic contaminants, and, in some cases, the presence of pathogenic bacteria. The aim of this study was to perform a survival experiment to demonstrate the importance of proper herbal brewing technique and to conduct a molecular and …

Varied Length Stokes Shift Bodipy-Based Fluorophores For Multicolor Microscopy, Amy M. Bittel, Ashley M. Davis, Lei Wang, Michel A. Nederlof, Jorge O. Escobedo, Robert Strongin, Summer L. Gibbs

Chemistry Faculty Publications and Presentations

Multicolor microscopy tools necessary to localize and visualize the complexity of subcellular systems are limited by current fluorophore technology. While commercial fluorophores cover spectral space from the ultraviolet to the near infrared region and are optimized for conventional bandpass based fluorescence microscopy, they are not ideal for highly multiplexed fluorescence microscopy as they tend to have short Stokes shifts, restricting the number of fluorophores that can be detected in a single sample to four to five. Herein, we synthesized a library of 95 novel boron-dipyrromethene (BODIPY)- based fluorophores and screened their photophysical, optical and spectral properties for their utility in …

Boiling Points Of The Propylene Glycol + Glycerol System At 1 Atmosphere Pressure: 188.6–292 °C Without And With Added Water Or Nicotine, Anna K. Duell, James F. Pankow, Samantha M. Gillette, David H. Peyton

Chemistry Faculty Publications and Presentations

No abstract provided.

Wildfire Emissions In The Context Of Global Change And The Implications For Mercury Pollution, Aditya Kumar

Dissertations, Master's Theses and Master's Reports

Wildfires are episodic disturbances that exert a significant influence on the Earth system. They emit substantial amounts of atmospheric pollutants, which can impact atmospheric chemistry/composition and the Earth’s climate at the global and regional scales. This work presents a collection of studies aimed at better estimating wildfire emissions of atmospheric pollutants, quantifying their impacts on remote ecosystems and determining the implications of 2000s-2050s global environmental change (land use/land cover, climate) for wildfire emissions following the Intergovernmental Panel on Climate Change (IPCC) A1B socioeconomic scenario.

A global fire emissions model is developed to compile global wildfire emission inventories for major atmospheric …

Synthesis, And Structural, Electrochemical, And Magnetic Property Characterization Of Promising Electrode Materials For Lithium-Ion Batteries And Sodium-Ion Batteries, Ruixin Han

Theses and Dissertations--Chemistry

Iron oxides, have been widely studied as promising anode materials in lithium-ion batteries (LIBs) for their high capacity (≈ 1000 mA h g^-1 for Fe₂O₃ and Fe₃O_4,), non-toxicity, and low cost. In this work, β-FeOOH has been evaluated within a LIB half-cell showing an excellent capacity of ≈ 1500 mA h g^-1 , superior to Fe₂O₃ or Fe₃O_4. Reaction mechanism has been proposed with the assistance of X-ray photoelectron spectroscopy (XPS). Various magnetic properties have been suggested for β-FeOOH such as superparamagnetism, antiferromagnetism and complex …

New Approaches To Cyclopentadienyl-Fused Thiophene Complexes Of Iron And Synthesis And Characterization Of Carbonic Anhydrase Active-Site Mimics For Co2 Hydration, Deepshikha Gupta

Theses and Dissertations--Chemistry

Polyheterocycles such as polythiophene and its derivatives comprise an important class of conducting polymers used for electronic applications. They have been of great interest for use in electronic materials due to their increased environmental stability as well as novel electronic properties in their polymer states. We have been interested in exploring the electronic properties of organometallic analogues of the low-band-gap polymer poly(benzo[3,4-c]thiophene) (polyisothianaphthene) that incorporates η⁵-cyclopenta[c]thienyl monomers such as ferroceno[c]thiophene. First chapter of this dissertation involved synthetic attempts to ferroceno[c]thiophene. Exploring a shorter synthetic route to starting material, 1,2-di(hydroxymethyl)ferrocene was …

Enhanced Analysis Of Lignin Dehydrogenation Oligomers Via Mass Spectrometry, Amber Suzanne Bowman

Theses and Dissertations--Chemistry

Effective analytical techniques need to be developed to characterize the products of lignin degradation experiments to be able to generate renewable products from lignin. Mass spectrometry is an valuable analytical approach for lignin characterizaion, but it is hindered by lignin’s poor ionization efficiency, especially in the positive ion mode. In this work, we attempt to improve lignin’s ionization by utilizing electrospray and laser desorption mass spectrometry coupled with the addition of cations and chemical derivatives. We confronted the ionization problem from both a top-down and bottom-up analytical approach by analyzing synthesized monomers, dimers, and polymers along with natural lignin extracts …

Spectroscopy And Formation Of Lanthanum-Hydrocarbon Complexes, Wenjin Cao

Theses and Dissertations--Chemistry

Lanthanum-mediated bond activation reactions of small hydrocarbon molecules, including alkenes, alkynes, and alkadienes, were carried out in a laser vaporization metal cluster beam source. Time-of-flight mass spectrometry and mass-analyzed threshold ionization (MATI) spectroscopy, in combination with quantum chemical and multi-dimensional Franck-Condon factor calculations, were utilized to identify the reaction products and investigate their geometries, electronic structures, and formation mechanisms.

La-hydrocarbon association was only observed in the reaction of La with isoprene. C-H bond activation was observed in all reactions, hydrogen elimination was observed as the prominent reaction for the alkenes (2-butene, isobutene, 1-pentene, and 2-pentene), alkynes (1-butyne, 2-butyne, and 1-pentyne), …

Multifunctional Nanocomposites In Coating Technology: Synthesis, Characterization, Formulation, Evaluation And Application, Sudeshna Chakraborty

Graduate Research Theses & Dissertations

Application of Nanomaterials using nanotechnology has gained significant

attention in the coating industry in recent years. Their application has had a great

impact, particularly in the 3C industries (computer, communication, and construction).

Incorporation of nanomaterials into polymer carriers through a systematic approach to

coating processes can enhance various physical properties, such as mechanical,

optical, electrical and thermal properties. The current dissertation focused on the

synthesis and characterization of new nanomaterials like mesoporous silica or

nanocomposites like copper-doped zinc oxide that can be used in the coating to study

thermal cooling performance and enhancement of thermal conductivity. New thermal

devices will …

Fundamental Studies Of Chemical Stability And Carrier Process In Hybrid Perovskite Materials, Jue Gong

Graduate Research Theses & Dissertations

This dissertation comprehensively studies the optoelectronic properties of organic-inorganic hybrid perovskites to fundamentally answer their foundations of outstanding performance on solar cells, photodetectors, nanowire lasers and other optoelectronic applications. Specifically, a novel type of charge carrier-lattice interaction was discovered in perovskite methylammonium lead iodide (CH3NH3PbI3), where photoluminescence lifetime of photoinduced carriers is strongly dependent on the rotational frequency of CH3NH3+, as modulated via substitution of hydrogens with deuterium atoms in the organic cation. In addition, two-dimensional Ruddlesden-Popper perovskite (CH3NH3)2Pb(SeCN)2I2 was first synthesized and characterized in the field, and its photoluminescence properties were systematically examined. The existence of intensive photoluminescence peak …

Evaluation Of Ispe For Inhibitor Design In The Non-Mevalonate Pathway, Kataryzna Barbara Hoerchler

Graduate Research Theses & Dissertations

There is an urgent need to discover new antibiotics to combat the emergence of drug resistant Novel antibiotics that target unique pathways different from existing therapies are promising targets. The non-mevalonate pathway (MEP), which was discovered in the 1990’s, is essential for most bacteria, plants and apicomplexan parasites. Inhibition of the non-mevalonate is an attractive pharmaceutical target, since it is not present in mammals. Many compounds have surfaced as potential inhibitors, but none have made it to market. This thesis investigates the fourth step in the MEP pathway involving the enzyme 4-diphosphocytidyl-2-C-methyl-D-erythritol kinase (IspE) from Escherichia coli (Ec), Burkholderia thailandensis …

Oxidation Of Β-O-4 Lignin Model Compounds And Application To Lignin Linkage Degradation Facilitated By Mechanochemical Treatment And Two-Step Oxidative Depolymerization, Soledad G. Yao

Theses and Dissertations--Chemistry

The oxidation of lignin model compounds was studied in conventional solvents in parallel with oxidations in ionic liquid solvents. Catalyst systems were investigated in ionic liquid solvents to determine how reaction rates and the selectivity for benzylic carbon oxidation were affected. Oxidation rates were often lower in ionic liquids than in conventional solvents ‒ as indicated by lower conversion in a standard reaction time ‒ likely due, at least in part, to the higher viscosity of ionic liquids. Mechano chemical treatment of Indulin AT kraft lignin by ball milling with KOH and toluene produced significant carbonyl functionality, among other changes. …

Applications Of Cell-Derived Vesicles: From Single Molecule Studies To Drug Delivery, Faruk H. Moonschi

Theses and Dissertations--Chemistry

Single molecule studies can provide information of biological molecules which otherwise is lost in ensemble studies. A wide variety of fluorescence-based techniques are utilized for single molecule studies. While these tools have been widely applied for imaging soluble proteins, single molecule studies of transmembrane proteins are much more complicated. A primary reason for this is that, unlike membrane proteins, soluble proteins can be easily isolated from the cellular environment. One approach to isolate membrane proteins into single molecule level involves a very low label expression of the protein in cells. However, cells generate background fluorescence leading to a very low …

Protein Suppression Of Flavin Semiquinone As A Mechanistically Important Control Of Reactivity: A Study Comparing Flavoenzymes Which Differ In Redox Properties, Substrates, And Ability To Bifurcate Electrons, John Patrick Hoben

Theses and Dissertations--Chemistry

A growing number of flavoprotein systems have been observed to bifurcate pairs of electrons. Flavin-based electron bifurcation (FBEB) results in products with greater reducing power than that of the reactants with less reducing power. Highly reducing electrons at low reduction midpoint potential are required for life processes of both aerobic and anaerobic metabolic processes. For electron bifurcation to function, the semiquinone (SQ) redox intermediate needs to be destabilized in the protein to suppress its ability to trap electrons. This dissertation examines SQ suppression across a number of flavin systems for the purpose of better understanding the nature of SQ suppression …

Carbon Quantum Dots: Bridging The Gap Between Chemical Structure And Material Properties, Timothy J. Pillar-Little Jr.

Theses and Dissertations--Chemistry

Carbon quantum dots (CQDs) are the latest generation of carbon nanomaterials in applications where fullerenes, carbon nanotubes, and graphene are abundantly used. With several attractive properties such as tunable optical property, edge-functionalization, and defect-rich chemical structure, CQDs have the potential to revolutionize optoelectronics, electro- and photocatalysis, and biomedical applications. Chemical modifications through the addition of heteroatoms, chemical reduction, and surface passivation are found to alter the band gap, spectral position, and emission pathways of CQDs. Despite extensive studies, fundamental understanding of structure-property relationship remains unclear due to the inhomogeneity in chemical structure and a complex emission mechanism for CQDs.

This …

Study Of The Effect Of Steric Bulk Of Side Chains On The Properties Of Conjugated Polymers, Bei Zhang

Theses and Dissertations--Chemistry

Donor-acceptor conjugated polymers opened a new era for conjugated polymer research due to the abundant selection and combination of different conjugated units. This class of polymers function as semiconductor materials with potential application in plastic consumer electronics. The frontier molecular orbital energies of the polymers are generally determined by the selection of donor and acceptor units in the backbone structure, and their substituents. The side chains attached to the backbone not only affect the solubility of the materials, but also their self-assembly and morphological characteristics, which indirectly govern optoelectronic properties. It is important therefore to consider backbone architectures and the …

Catalytic Conversion Of Monosaccharides Into 5-(Hydroxymethyl)Furfural In Ionic Liquids Using Aluminum Complexes Bearing Bidentate (Aminomethyl)Phenolate Ligands, Daudi Sayialel Saang'onyo

Theses and Dissertations--Chemistry

Currently, the major sources of fuel, energy, and chemicals are nonrenewable fossil resources such as petroleum, natural gas, and coal. Additionally, petroleum is used for the production of most transportation fuels and for the production of about 95% of organic chemicals. However, the production and use of non-renewable fossil fuels are unsustainable. For economic and environmental sustainability, there is a need to search for new and/or renewable resources and technologies for energy, fuels, and chemicals production that have the potential of effectively substituting fossil resources. In this context, lignocellulosic biomass is one of the candidates that meet these requirements due …

Heterogeneous Catalytic Deoxygenation Of Lipids To Fuel-Like Hydrocarbons Over Improved Bimetallic Nickel Catalysts, Ryan Andrew Loe

Theses and Dissertations--Chemistry

Diminishing petroleum reserves and environmental considerations have strengthened the demand for developing renewable fuel technologies. One alternative is deoxygenating plant oils, animal fats, and waste lipid streams to fuel-like hydrocarbons. These fuels offer a drop-in replacement to petroleum products while potentially becoming carbon neutral, satisfying both fuel and environmental concerns. This fuel is obtained through catalytic deoxygenation via either hydrodeoxygenation (HDO) or decarboxylation/ decarbonylation (deCO_x). HDO requires problematic sulfided catalysts and extreme hydrogen pressures to convert lipids to fuel-like hydrocarbons. Therefore, this work focuses on the deCO_x pathway, where hydrogen is not required for deoxygenation to take …

Design And Synthesis Of Functional Organic Materials, Anthony Joseph Petty Ii

Theses and Dissertations--Chemistry

Control of solid state ordering in conjugated small molecules is paramount to the continued development and implementation of organic materials in electronic devices. However, there exists no reliable method on which to predicatively determine how a change to the molecular structure will impact the solid-state packing. As such, the molecule must be synthesized before its solid-state packing can be definitively evaluated. However, once the packing structure of a material is known there exist both qualitative structure- function relationships derived from the literature, as well as quantitative computational methods that can be employed to suggest if a material will perform well …

Aqueous Photochemistry Of 2-Oxocarboxylic Acids, Alexis Eugene

Theses and Dissertations--Chemistry

Atmospheric aerosols affect climate change by altering the energy balance of the atmosphere, and public health due to their variable chemical composition, size, and shape. While the formation of secondary organic aerosol (SOA) from gas phase precursors is relatively well understood, it does not account for the abundance of SOA observed during field measurements. Recently it has become apparent that in-aerosol aqueous chemical reactions likely provide some of the missing sources of SOA production, and many studies of aqueous phase processes are underway.

This work explores the fates of the simplest 2-oxocarboxylic acids, glyoxylic acid (GA) and pyruvic acid (PA), …

Evaluation Of Autonomously Measured Alkalinity, Ph, And Pco2 Variability On A Coral Reef, Brittany Peterson

Graduate Student Theses, Dissertations, & Professional Papers

Currently, our understanding of alkalinity (A_T) variability in highly dynamic environments such as coral reefs is limited by the dearth of A_T measurements. In order to better characterize these environments, high temporal resolution A_T data are needed. This work employed the newly developed Submersible Autonomous Moored Instrument for Alkalinity (SAMI-alk), a fully autonomous in situ A_T analyzer, to study seawater A_T variability. The main goals of this research were to evaluate the utility of combining the SAMI-alk data with currently available in situ measurements of pH and partial pressure of carbon dioxide (p …

Relationships Among Vitamin D Deficiency, Metabolic Syndrome, Smoking Behavior, And Physical Activity, Ethan Pham

Walden Dissertations and Doctoral Studies

Aging increases the risk of both vitamin D deficiency and metabolic syndrome. Vitamin D deficiency and metabolic syndrome may be related, although there are mixed findings. Furthermore, literature suggests other factors such as physical fitness activity and smoking behavior are associated with Vitamin D deficiency and the development of metabolic syndrome. A number of studies have documented associations between Vitamin D levels and physical fitness activities, while other studies found correlations between Vitamin D levels, metabolic syndrome, and smoking behavior. However, no previous study has examined the links between physical fitness activity, smoking behavior, Vitamin D levels, and the risks …

Bimetallic Complexes: The Fundamental Aspects Of Metal-Metal Interactions, Ligand Sterics And Application, Michael Bernard Pastor

University of the Pacific Theses and Dissertations

Metal containing complexes have been used to catalyze various organic transformations for the past few decades. The success of several mononuclear catalysts led to transition metal catalysts used in pharmaceuticals, environmental, and industrial processes. While mononuclear complexes have been used extensively, bimetallic systems have received far less attention. Bimetallic or polynuclear sites are commonly found in metalloenzymes that perform elegant transformation in biological systems, underlying their significance. Inorganic chemists take inspiration from nature and design model bimetallic complexes to further study this cooperativity effect. A bimetallic platform offers many structural and functional differences such as the identity of the metal …

Aerogels For Energy Storage Applications: From Shape Memory Materials To Thermites And Explosives, Suraj Donthula

Doctoral Dissertations

"Aerogels are three dimensional highly porous solid objects that provide density reduction compared to dense objects. Those materials can have applications in different classes of energy storage and the two types that are focused in this dissertation are mechanical energy and thermal energy storage. Shape memory materials can store and recover elastic deformation energy when triggered by an external stimulus such as temperature. To incorporate those properties, shape memory polymeric aerogels (SMPA) were synthesized from a rigid isocyanurate containing triisocyanate (N3300 A) and four short oligomeric derivatives of ethylene glycol: H(OCH₂CH₂)_nOH (1 ≤ n …

Evaluation Of The Redesign Of A Stem Gatekeeper Course, General Chemistry I, Incorporating Active-Learning Strategies And Implementation Of A Student-Choice Model, Travis Rae Mcdowell

Doctoral Dissertations

"The first courses freshman university students typically enroll in are the introductory science and math, courses that bridge from and build upon their prior educational experiences. These introductory courses often have large enrollment lectures coupled with supplemental sessions to teach using traditional educational practices, which may operate counter to the attitudes and culture of the students who take them. To address this, the general chemistry faculty through collaboration with a team of educational specialists initiated a redesign of the general chemistry course, which primarily serves first-year undergraduates. The redesign efforts included changes such as reducing lecture time and placing emphasis …

Electrodeposited Semiconductor Nanostructures & Epitaxial Thin Films For Flexible Electronics, Naveen Kumar Mahenderkar

Doctoral Dissertations

"Single-crystal Si is the bedrock of semiconductor devices due to the high crystalline perfection which minimizes electron-hole recombination, and the dense native silicon oxide which minimizes surface states. To expand the palette of electronic materials beyond planar Si, an inexpensive source of highly ordered material is needed that can serve as an inert substrate for the epitaxial growth of grain boundary-free semiconductors, photonic materials, and superconductors. There is also a need for a simple, inexpensive, and scalable fabrication technique for the growth of semiconductor nanostructures and thin films. This dissertation focuses on the fabrication of semiconducting nanowires (polycrystalline Ge & …

Cappack Devices For The Evaluation Of Parameters And Pulse Performances In Liquid And Solid-State Nmr Spectroscopy, Lingyu Chi

Doctoral Dissertations

"NMR spectroscopy is a powerful analytical tool to obtain explicit information about molecular structures, conformations, dynamics, and functions. To extract the desired information most accurately, NMR reference standards and devices are needed for calibrating the spectrometer hardware, generating reference data for the NMR software, and testing the applicability of pulse sequences. In this dissertation, the CapPack (Capillary-tube Package) platform is introduced which provides well-defined external reference and calibration standards for liquid and solid-state NMR applications. CapPacks consist of one or more permanently sealed capillary tubes that, depending on the intended application, come arranged in different geometries such as side-by-side or …