Chemistry Commons^™

Differentiation Of Human, Animal And Synthetic Hair By Atr Ftir Spectroscopy, Jeremy Manheim

Chemistry

Hair fibers are ubiquitous to every environment and are the most commonly found form of trace evidence at crime scenes. The primary difficulty forensic examiners face after retrieving a hair sample is determining who it came from. Currently, the methodology of microscopic examination of potential hair evidence is absent of statistical probability and is inherently subjective. Another method, involving DNA analysis, takes months to conduct and the majority of times is unsuccessful due to its degradation and absence from the hair. Here, Attenuated Total Reflectance (ATR) Fourier Transform Infrared (FTIR) Spectroscopy coupled with advanced statistics was used to identify a …

Green Chemistry As A Tool For Understanding The Toxic Substances Control Act: A Lecture Module For Undergraduate Students, Molly R. Blessing

Honors Scholar Theses

The Toxic Substances Control Act (TSCA) is the central form of chemical regulation existent in the United States today, yet scientists are often unaware or uncertain of its provisions. Violations of TSCA by unknowing chemists set industry and government unnecessarily at odds. A lecture on TSCA was developed for undergraduate students that uses the concept of green chemistry to promote interest and incentivize learning. Green chemistry methods are cleaner and less wasteful than traditional chemical ones, and many companies using them are at the forefront of technological innovation. The lecture explains both green chemistry and TSCA, includes company case studies, …

Inertial Force-Driven Synthesis Of Near-Infrared Plasmonic Nanosphere Composites: Physicochemical Characterizations, Joseph Noel Batta-Mpouma

Graduate Theses and Dissertations

Near-infrared (NIR) responsive nanoparticles (NPs) like gold nanorods (GNRs) are important in biomedical fields because of their transparency for biological tissues. Although GNRs are sought after as contrast agents for theranostics in cancer studies, capping ligands like cetyltrimethylammonium bromide (CTAB) for the GNR synthesis are toxic for biological tissues. The need for an alternative to toxic GNRs is of interest to alleviate the problem.

This work aimed to optimize the synthesis of NIR responsive nanosphere composites (NSCs) by inertial force (g-force) using colloidal gold NPs as model, elucidate the mechanism for the NSC formation, and study their detailed physicochemical characteristics. …

Novel [3,3]- And [1,3]- Rearrangements Of Azole-Derived N,X-Ketene Acetals, Sefat A. Alwarsh

Graduate Theses and Dissertations

The formation of carbon-carbon bonds in organic chemistry is fundamentally important. One of the major reactions that chemists have widely investigated is the Claisen rearrangement. Based on the fundamental features of this rearrangement, chemists exploited the capability of the transformation and invented their own variations of Claisen-type rearrangements. Our goal in this project is to develop a novel variation of the Claisen rearrangement using azole compounds, which are common heteroaromatic ring systems that are present extensively in the biomedically important natural products. We propose here novel methodologies of preparing 2-substitution azole derivatives using aza-based Claisen rearrangement, N,X-ketene acetals that requires …

The Use Of Shape Memory Polymers As A Tool To Study Human Fibrosarcoma And Murine Mesenchymal Stem Cell Migration, Justin N. Elkhechen

Renée Crown University Honors Thesis Projects - All

Shape memory polymers (SMPs) are a class of “smart” materials that can transform between two distinct conformations through external stimuli, such as heat or electricity. Their usage in bioengineering has led to a promising field of research that lies at the interface of cell and mechanobiology, potentially providing insight into cancer therapies and tissue development—two processes that exist in dynamic environments in vivo. The present work involves creating new, shape changing, scaffolds for studies to analyze cell migration upon changes to the environmental topography. Specifically, this Capstone has been primarily focused on the development of a “half and half” fibrous …

Growth Of Ordered Nanostructure Arrays Including Nanotubes And Nanorods For High Efficiency Solar Cells, Wipula P. Liyanage, Manashi Nath

Chemistry Faculty Research & Creative Works

A simple and straightforward approach has been described for the fabrication of CdTe nanotube and nanorod arrays with a high degree of precision through confined electrodeposition on lithographically patterned nanoelectrodes. This technique has the potential of growing these nanotube/nanowire arrays with extreme uniformity over a significantly large area. the desired nanoelectrode pattern was defined through electron beam lithography on indium tin oxide coated glass, and electrodeposition of the semiconducting material of interest (CdTe) on the nanoelecrodes produced the nanotubes/nanowires. It is interesting to note that the measured photocurrent density of nanotube device created by this protocol exceeds that obtained from …

A Rapid Lc-Ms/Ms Method For Quantification Of Csuoh0901, A Novel Antitumor Agent, In Rat Plasma, Ramakrishna R. Voggu, Ravali Alagandula, Xiang Zhou, Bin Su, Bo Zhong, Baochuan Guo

Chemistry Faculty Publications

CSUOH0901, a novel anticancer derivative of nimesulide, exhibits very promising anticancer activities in various cancer cell lines. In order to support further pharmacological and toxicological studies of this promising anticancer drug candidate, an LC-MS/MS method was developed and validated in accordance with the US Food and Drug Administration guidelines. The drug molecules were extracted from plasma samples by protein precipitation and then analyzed with LC-ESI-MS/MS. An excellent analyte separation was achieved using a phenomenex C18 column with a mobile phase of 90% methanol and 5 m m of ammonium formate. The validated linear dynamic range was between 0.5 and 100 …

Synthesis And Characterization Of Rhodium Acetate With Functionalized Benzonitriles, Jared M. Lowe

Undergraduate Honors Theses

Dirhodium complexes are effective catalysts in carbene transformations. These reactions involve chemistry between the catalyst and a carbene generated in situ. In order to better understand the rhodium-carbon bond, studies of rhodium acetate, Rh₂(OAc)₄, and a variety of functionalized benzonitriles were proposed. Diadducts of rhodium acetate with 4-nitrobenzonitrile, 4-aminobenzonitrile, 4-(dimethylamino)benzonitrile, and 3,5-dinitrobenzonitrile were successfully prepared and characterized by X-ray crystallography. IR and NMR spectroscopy were also employed for characterization purposes.

Increased Microdialysis Recovery Of Large Molecular Weight Analytes Via Ultrafiltration, Michael C. Elkins

Chemistry & Biochemistry Undergraduate Honors Theses

Microdialysis is a sampling method based on the passive diffusion of solutes across a semi-permeable hollow-fiber membrane that is driven by a concentration gradient. The membrane has a defined molecular weight cutoff, which causes larger molecular solutes such as proteins with molecular weights of approximately 8-80 kDa to have low recoveries. The purpose of this research is to utilize ultrafiltration across the membrane through push-pull and vacuum ultrafiltration methods as a means to increase recovery of large molecular weight analyte. These experiments were carried out using Methyl Orange (MO), Fluorescein Isothiocyanate 4 kDa (FITC-4), and Fluorescein Isothiocyanate 40 kDa (FITC-40). …

Biomimetic Adhesive Thiol-Ene Films For Improved Adhesion, Laken L. Kendrick

Honors Theses

Current dental restoration materials fall short in adhesion and often pull away from the surface of the tooth upon curing. This project seeks to design polymers that can adhere to wet, heterogeneous surfaces as potential materials for dental restoration applications. The goal of this project is to mimic the structure and adhesive properties of natural adhesives containing 3,4-dihydroxyphenyl-L-alanine (DOPA). We will synthesize mono- and di-functional DOPA derivatives with catechol functionality and investigate their adhesion compared to their non-catechol-containing alternative through incorporation into a model thiol-ene photopolymerization. Functional group conversion, real time kinetics, and adhesion data will be used to analyze …

Analysis Of The Mechanical Properties Of Dgebf/4,4’-Dds Thermoset Systems As A Function Of Cure Rate, Chase B. Thompson

Honors Theses

The relationship between macroscopic mechanical and thermal properties and ramp rate during cure of epoxy-amine systems consisting of the epoxide resin digylcidyl ether of bisphenol F (DGEBF, provided Hexion specialty chemicals) and 4,4-diaminodiphenyl sulfone (4,4-DDS, provided by Atul Sulpho) were probed using Dynamic Mechanical Analysis (DMA), Positron Annihilation Lifetime Spectroscopy (PALS), and compression testing. These systems were cured in a programmable oven; the samples were heated from 35°C to 180°C at ramp rates of 0.5, 1.0, 1.5, 2.0, 2.5, 5.0, 10, and 15°C/min. Even as the ramp rates during the cure of these materials was changed, there was very little …

Polymerization Of Blocked Isocyanate Functional Polymer Surfaces And Post-Polymerization Modification By Thiol-Isocyanate Reactions, Chase A. Tretbar

Honors Theses

Direct polymerization of isocyanate-functional monomers has been achieved with controlled radical polymerizations (CRP) for precisely engineered modification platforms with highly reactive side chains. However, despite the success of these strategies, the inherent reactivity of isocyanates still leads to adverse side reactions, such as hydrolysis, that are difficult to suppress. Phenol, lactam, and oxime-based blocking agents have been used to limit the reactivity of isocyanates in applications such as multicomponent urethane coating systems. The reactivity of these blocked isocyanates can be restored by thermal deprotection of the blocking agent to achieve the desired reactions. In this work, we use blocked isocyanate-functional …

Methanogen Metabolism In The Presence Of Iron Compounds: A Martian Environment Simulation, Monroe Phillip Cowan

Chemistry & Biochemistry Undergraduate Honors Theses

The climate on the face of Mars is hostile towards life. Thus, any organisms potentially living on Mars would likely inhabit a subsurface environment, in which conditions are wetter and warmer. However, organisms living beneath the surface would be significantly deprived of light and some organic compounds necessary for the sustenance of most life. The discovery of methane gas in Mars’ atmosphere has led to speculation that methanogens, obligate anaerobes which produce methane as waste, are the organisms most likely to survive in a subsurface environment. These members of domain Archaea subsist on water, hydrogen, and carbon dioxide. In addition, …

Analysis And Comparison Of The Photodecomposition Reaction Of Methanol On Ceo2 Impregnated Tio2 Surfaces Versus Bare Tio2 Surfaces, Christopher A. Estes

Master of Science in Chemical Sciences Theses

Titanium dioxide (TiO₂) has been well-studied primarily due to its unique photocatalytic activity. Different preparation techniques have been developed to increase its photocatalytic activity by various means, including simply increasing the surface area, changing the makeup of the framework, and modifying the surface with a dopant. This study focuses on the effect cerium oxide (CeO₂) has on the photocatalytic activity of TiO₂ by depositing CeO₂ on the TiO₂ surface. Methanol is used as a probe reactant for these experiments due to its wide use in heterogeneous catalysis research and the limited products that …

Synthesis Of Novel Dienes And Cyclic Compounds Via Olefin Metathesis Reactions Catalyzed By The Second Generation Grubbs Catalyst, Patrick Joseph Carey

Honors Theses

Transition metal-catalyzed olefin metathesis reactions play a significant role in chemical synthesis. These reactions are currently applied across several disciplines, and their full potential has not yet been reached. This project details the synthesis of spiro[3-cyclopentene-1,9’-[9H]fluorene], 1-(1-amino-2-methylpropyl)-3-cyclopentenol, and the eugenol dimer via olefin metathesis reactions catalyzed by the second generation Grubbs catalyst. The unique structural properties of each compound help demonstrate the widespread abilities of these reactions. Also reported are the novel three-dimensional crystal structures of both spiro[3-cyclopentene-1,9’-[9H]fluorene] and the eugenol dimer. These structures were determined via X-ray diffraction crystallography methods using a Bruker SMART X2S Single Crystal Diffractometer. Both …

Determination Of Antibiotic Release From Electrospun Nanofibers, John P. O'Brien Iii

Honors Theses

Decreasing the risk of infection following surgery for traumatic bone breaks is a major focus of the medical and scientific community. Drug delivery devices are emerging as powerful solutions for combating infection following these procedures. Current devices, however, suffer several drawbacks including poor antibiotic release rate and control the devices themselves not being biodegradable. This thesis studies the \textit{in vitro} release rate for antibiotics tobramycin and vancomycin from a biodegradable medical implant. Antibiotics, collagen, and bone growth factors are incorporated into Poly(lactide-co-glycolide)-based electrospun nanofibers by local company eSpin for development. The drug-loaded nanofibers are immersed in phosphate buffered saline (PBS) …

Modifications Of Lysozyme By Substituted Benzoquinones, Hendrik J. Greve

Honors Theses

Amyloidosis, which involves the precipitation of mis-folded protein aggregates, is a prominent process that occurs in many neurodegenerative conditions such as Alzheimer's disease and Parkinson's disease; the protein aggregates being amyloid-β for Alzheimer’s disease and α-synuclein for Parkinson’s disease. This study has focused on lysozyme modifications induced by metabolites of the commonly found pollutants known as polycyclic aromatic hydrocarbons (PAHs). PAHs are found in substances ranging from grilled meats to cigarette smoke to cosmetics, and they can be metabolized into a family of biological toxins known as benzoquinones. The molecules of interest for this study were 1,4-benzoquinone (pBQ), 2-chloro-1,4-benzoquinone (CBQ), …

Ribonuclease A Modification Induced By 1,2-Naphthoquinone And 2-Hydroxy-1,4-Naphthoquinone, Michelle Dawn Smith

Honors Theses

Protein modifications may occur upon exposure to environmental toxins such as polycyclic aromatic hydrocarbon (PAH) molecules or their metabolites. In this context, our laboratory was interested in investigating protein modifications in the presence of select naphthoquinones, which were 2-hydroxy-1,4-naphthoquinone (HNQ) and 1,2-naphthoquinone (o-NQ). The effects of HNQ and o-NQ on the protein Ribonuclease A (RNase) were investigated through a variety of conditions. These modified incubation conditions included pH variation and the addition of metal ions to further mimic physiological conditions. Documentation of results was carried out through sodium dodecyl sulfate polyacrylamide gel electrophoretic analysis (SDS-PAGE). Of the two quinones, o-NQ …

Distributed Drug Discovery: Synthesis Of Unnatural Amino Acids As Potential Antimalarial Drugs, Amanda Dugan

Honors College

Through the collaboration of many institutions across the globe, the Distributed Drug Discovery project founded at Indiana University-Purdue University Indianapolis seeks to aid in the development of drugs for the developing world. In response to two antimalarial assay hits, our team at Abilene Christian University has synthesized many unnatural amino acid analogs using resin-based combinatorial chemistry. Proton nuclear magnetic resonance spectroscopy has been used to characterize the compounds and thin layer chromatography to determine purity. All compounds were purified on hypersep cyanosilica columns.

Analysis Of Free Solute Fractions And Solute-Protein Interactions Using Ultrafast Affinity Extraction And Affinity Microcolumns, Xiwei Zheng

Department of Chemistry: Dissertations, Theses, and Student Research

This dissertation describes the use of a high-performance affinity chromatography method based on ultrafast affinity extraction and microcolumns to study biological interactions.

In the first project, a new method was created and based on ultrafast affinity extraction to determine both the dissociation rate constants (k_d) and association equilibrium constants (K_a) for drug-protein interactions in solution. Various conditions to optimize the use of ultrafast affinity extraction for equilibrium and kinetic studies were considered.

The objective of the next portion of this dissertation was to develop a chromatographic approach to measure free drug fractions in more …

Chromatographic Analysis Of Drug-Protein Interactions During Diabetes And Characterization Of Human Serum Albumin Through Multidimensional Mass Spectrometry, Ryan E. Matsuda

Department of Chemistry: Dissertations, Theses, and Student Research

Diabetes is a metabolic disease that can lead to the non-enzymatic glycation of serum proteins such as human serum albumin (HSA). Previous studies have indicated that glycation can affect the structure and function of these proteins. This dissertation describes the development of tools and techniques based on high performance affinity chromatography (HPAC) and multidimensional mass spectrometry to analyze the effects of glycation on the function and structure of HSA.

A major portion of this research involved the utilization of HPAC to examine the effect of glycation on the binding of three second-generation sulfonylurea drugs and one third-generation sulfonylurea drug. These …

Investigations Into The Molecular Mechanisms Of Bacterial Pathogen–Host Interactions: Construction Of A Dual Plasmid System For Incorporation Of Unnatural Amino Acids Into Pseudomonas Syringae Pv. Tomato Dc3000, Scotty D. Raber

Department of Chemistry: Dissertations, Theses, and Student Research

A dual plasmid system for the incorporation of unnatural amino acids into plant pathogen, Pseudomonas syringae pv. tomato DC3000, has been designed. This invention is expected to allow (a) mutations of proteins synthesized by the bacterium, P. syringae pv. tomato DC3000, that can capture molecular targets, especially for such modified proteins secreted by the phytopathogen into the host plant cells of A. thaliana and S. lycopersicum, (b) expression of biological probes in the bacterial species to monitor changes in redox, nutritional, and other small molecule states over pre-, post- and in situ disease stages, and secretion of such biological …

Molecular Mechanism For The Biosynthesis Of Antifungal Hsaf And Antibacterial Wap-8294a2, Haotong Chen

Department of Chemistry: Dissertations, Theses, and Student Research

Bioactive natural products are a major source of anti-infectives. Many ubiquitous inhabitants of soil and water, such as the Gram-negative, prolific producers of natural products, Lysobacter, remain largely unexplored. This PhD thesis reports our studies of the biosynthetic mechanism for a novel antifungal natural product HSAF and a potent anti-MRSA natural product WAP-8294A2.

In the first chapter, we give a short review of the biosynthesis of polyketides, focusing on those which exhibit new biosynthetic features. In subsequent chapters, we present original research on the biosynthetic mechanisms of dihydromaltophilin, a heat stable antifungal factor (HSAF). HSAF is the main antifungal …

Mechanochemical Investigation Of A Glassy Epoxy-Amine Thermoset Subjected To Fatigue, Stephen Finley Foster

Dissertations

Covalent bonds in organic molecules can be produced, altered, and broken through various sources of energy and processes. These include photochemical, thermochemical, chemical, and mechanochemical processes. Polymeric materials derive their physical properties from the time scale of motion, summation of intermolecular forces, and number of chain entanglements and crosslinks. Glassy thermoset polymers experience mechanical fatigue during dynamic stress loading and properties diminish with inevitable material failure at stress levels below the ultimate tensile strength (UTS). Damage modeling has been successful in predicting the number of cycles required to induce failure in a specimen due to stress. However, it does not …

Investigations Of The Photocatalytic Activity And Self-Cleaning Properties Of Polyhedral Oligomeric Silsesquioxane (Poss) Containing Titania Thiol-Ene Films, Lacrissia Unsonta Jefferson

Dissertations

In this document the film composition, self-cleaning aspect, photocatalytic efficiency, and methods employed to analyze a novel photocatalytic titania-containing thin film was evaluated. A primary objective of this research project was to assess the conditions required to achieve a stable titania dispersion for the photocatalytic coating and to determine the extent to which the presence of additives contributes to this process. Modified titania dispersions were prepared and characterized via dynamic light scattering (DLS), transmission electron microscopy (TEM), fourier transmission infrared spectroscopy (FTIR) and thermogravimetric analysis (TGA). Characterization details of the previous focus on the influence of polyhedral oligomeric silsesquioxane (POSS) …

Aqueous Raft Polymerization Of Glycopolymers For Peptide Interaction Studies And Antimicrobial Peptide Mimics For Antimicrobial Activity And Selectivity Studies, Sarah Elizabeth Exley

Dissertations

The first section of this work describes the synthesis and characterization of novel glycopolymers synthesized to model GM1 gangliosides, a glycolipid found in neuronal cells. Glucose and galactose were attached to N-hydroxyethyl acrylamide, using chemistry that granted control over the stereochemistry at the C1’ carbon of each saccharide, and polymerized via aqueous RAFT (aRAFT). Homopolymers, targeting either 30 or 300 DP, and copolymers, with N-dimethyl acrylamide, were prepared as a glycopolymer platform for investigation of amyloid β (Aβ), a naturally occurring peptide associated with Alzheimer’s disease, aggregation. Aβ aggregation kinetics and aggregate size in the presence of glycopolymer were determined. …

Oxidation Of Dibenzothiophene To Dibenzothiophene-Sulfone Using Molybdenum (Vi) Oxide, Tungsten (Vi) Oxide, And Ratios Of Molybdenum (Vi) Oxide And Tungsten (Vi) Oxide At Atomspheric Pressure, Sean M. Pelfrey

Theses and Dissertations - UTB/UTPA

This is a study of the catalytic oxidation of dibenzothiophene to dibenzothiophene sulfone using molybdenum (VI) oxide, tungsten (VI) oxide, and mixtures of molybdenum (VI) oxide and tungsten (VI) oxide at atmospheric pressure. The oxidative desulfurization reaction is studied with respect to the kinetics and thermodynamics of the process. Five catalysts were synthesized using a precipitation reaction. The five catalysts were 100% MoO3, 75/25% MoO3/WO3, 50/50% MoO3/WO3, 25/75% MoO3/WO3, and 100% WO3. Each catalyst was calcinated at three different temperatures 250oC, 500oC, 750oC and characterized using X-Ray Diffraction. Reactions of DBT-catalyst were held, under reflux, at temperatures from 140 oC …

Removal Of Cobalt And Nickel From Water Using Mno2 And Mn3o4 Nanomaterials, Maria Dolores Pacheco

Theses and Dissertations - UTB/UTPA

Nanomaterials MnO2 and Mn3O4 were synthesized using a titration/precipitation technique and characterized with powder XRD. A pH assay determined the optimum binding for cobalt and nickel occurred at pH 5 for both nanomaterials. A time dependency study determined that cobalt and nickel required more time with MnO2 for maximum adsorption than Mn3O4. The binding capacity study showed cobalt and nickel have good binding capacity with both nanomaterials. Interfering ion assay in the presence of Na+ , Ca2+ and Mg2+ showed minimal difference in the adsorption of cobalt and nickel to MnO2 or Mn3O4. Cobalt and nickel showed a reduction in …

Effect Of Crimping, Multilayering, And Twisting On Polymer Fibers For Acl Replacement, Mariana Ocampo

Theses and Dissertations - UTB/UTPA

The Anterior Cruciate Ligament (ACL) is the most common knee injury in the United States; roughly 150,000 ACL surgeries are performed annually. The ACL lacks self-healing properties due to its location inside the knee’s intra – articular environment (IA). Treatments for ACL ruptures involve the use of autogenous grafts or allografts. More suitable treatments can be found in new bio engineered tissue scaffolds, composed of natural and synthetic polymers. The polymers provide stronger mechanical properties and the ability to promote cell adhesion. It is believed that mimicking the crimping pattern of human ligaments will enhance polymer properties. Four polymers were …

Methodology Development In Green Chemistry: Oxoammonium Salt Oxidations And Fluoroform Incorporation, Rebecca J. Wiles

Honors Scholar Theses

Central to the advancement of small molecule synthesis is the ability to develop methodologies that reimagine well known chemistry in a new, environmentally friendly manner. In this thesis two central themes emerge: oxoammonium salt oxidations and trifluoromethyl incorporation using fluoroform gas. Several projects have been developed surrounding oxoammonium salt chemistry, which are featured by their mild conditions, ease of use, and the metal-free, recyclable nature of the oxidant. Trifluoromethylation using fluoroform gas finds its utility in the use of a potent greenhouse gas waste product as a benchtop reagent.