Chemistry Commons^™

High Temperature Electrochemical Engineering And Clean Energy Systems, Brenda L. Garcia-Diaz, Luke Olson, Michael Martinez-Rodriguez, Roderick Fuentes, Hector Colon-Mercado, Josh Gray

Journal of the South Carolina Academy of Science

Global power demand is projected to more than double by 2050 and meeting this increased power demand will require maintaining or increasing power output from all existing energy sources while adding a large amount of new capacity. The power sources that have the greatest opportunity to fulfill this demand gap over this time period are clean energy sources including solar and nuclear power. One of the areas of expertise that SRNL has been applying to help with a variety of clean energy technologies is in high temperature electrochemistry. Savannah River National Laboratory (SRNL) in collaboration with industrial and university partners …

Development Of A Luminescent Polymer Sensor Array For The Discrimination Of Carboxylates And Further Improvements In A Solvent Programmable Polymer, William J. Richardson

Theses and Dissertations

This thesis summarizes the work performed on two stimuli responsive polymer projects. The first project used a lanthanide based luminescent polymer to create a sensor array for carboxylate analytes. Initial attempts incorporated molecular imprinting as a means to incorporate unique selectivity into the polymer by introducing acetate, benzoate, and phenylacetate as templates prior to polymerization. This process was successful at creating unique sensing elements for the array, but the polymers lacked the specific selectivity typically seen in molecularly imprinted polymers (MIPs). Instead, a ligand displacement mechanism that relied on multiple sensors with different labile anion ligands directly complexed with the …

Understanding The Activity Of Model Catalyst Surfaces: Ultrahigh Vacuum And Atmospheric Pressure Studies, Kangmin Xie

Theses and Dissertations

Heterogeneous Catalysis plays an extremely important role in the world. Metal particles supported on oxide supports are the most widely employed heterogeneous catalysts. In order to provide insight into the development of new catalytic materials, a fundamental understanding of surface reactions is required. Vapor-deposited metal clusters on single-crystal surfaces are well-defined systems that can be used to understand the structure-relationships in commercial catalysts. The pressure gap between fundamental surface analysis under ultra-high vacuum (UHV, P~10-10 Torr) conditions and kinetic evaluation of catalysts under realistic pressures has been bridged by constructing a micro-reactor interfaced with UHV chamber: pre- and post-reaction surfaces …

Measurement Of Non-Covalent Aromatic Interactions Using Molecular Balances, Jung Wun Hwang

Theses and Dissertations

Non-covalent aromatic interactions govern many of the unique structures and properties of biological and synthetic molecules. Despite the importance of these interactions, their weak nature makes it challenging to study the interactions. To accurately measure weak non-covalent aromatic interactions in solution, we have designed molecular torsion balances that provide a quantitative measure of non-covalent intramolecular interaction strengths. First, we investigated the importance of electrostatic interactions in aromatic interactions. Substituent effects were strongly correlated with electrostatic Hammett parameters. In addition, the substituent effects were additive and showed significant direct substituent-arene interactions that support the recent direct substituent effect model. Next, the …

Forensic Characterization Of Dyes From Synthetic Textile Fibers Exposed To Outdoor And Laundering Effects By Ultra Performance Liquid Chromatography And Spectral Analysis, Molly Rebecca Burnip

Theses and Dissertations

Textile fibers found in an investigation are trace evidence that can connect a suspect to a victim or crime scene. Examination involves comparison of the color and morphology of a questioned fiber to a known fiber with optical spectroscopy. Fibers are considered class evidence, so evaluating more characteristics increases their significance as evidence if a match cannot be excluded. Acrylic, nylon, and polyester are textile polymers that require different extraction solvents based on the polymer chemistry. Methods have been developed for UPLC analysis of basic dyes on acrylic, acid on nylon, and disperse dyes on polyester. After microextraction from single …

Renewable Bio-Based Intermediates, Monomers And Polymeric Materials From Plant Oils, Liang Yuan

Theses and Dissertations

In the dissertation work, new chemical intermediates, monomers and thermoplastic polymers were derived from renewable soybean oil. Elastomers were further developed using monomers and polymers from soybean oil. The properties of these polymeric materials were characterized and discussed.

In Chapter 1, the overall background and recent development polymers from renewable biomass, especially plant oils, is introduced. Major research objectives of my doctoral research were described.

The first section of the dissertation, on the preparation of renewable intermediates, novel monomers and homopolymers, is provided in Chapter 2 and Chapter 3. In Chapter 2, amidation of soybean oil with amino alcohols was …

Virus Particles Provide Nanotopographical Cues For Osteogenic Differentiation Of Mesenchymal Stem Cells, Kamolrat Metavarayuth

Theses and Dissertations

One key aspect of tissue engineering is to develop biomimetic scaffolding materials that can modulate the proliferation, self-renewal and differentiation of multipotent stem cells into different lineages. Bone marrow derived mesenchymal stem cells (BMSCs) can differentiate into several target cells such as osteoblasts, chondrocytes, adipocytes, and smooth muscle cells. BMSCs are commonly used for in vitro osteogenesis studies in bone tissue engineering field. However the mechanisms and signaling pathways that these cells use to recognize and response to biomaterial surface are still unclear. This dissertation focuses on investigating the effect of chemical and physical cues introduced by virus nanoparticles on …

The Role Of Ferric Oxide Particles As Sources And Sinks Of Reactive Oxygen Species During The Autoxidation Of Ferrous Iron, Shengnan Meng

Theses and Dissertations

The oxic portion of the biosphere is a metastable mixture of different oxidation states of carbon, sulfur and oxygen energetically poised from equilibrium by the net rate differentials between photosynthetic carbon fixation and its metabolic or abiotic oxidation. The direct reaction of dioxygen with reduced carbon or sulfur is spin forbidden and therefore kinetically slow, but ferric and ferrous iron species serve as catalysts for enabling their oxidation and therefore play critical roles in the environment. This thesis reports exploratory and hypothesis driven research that seeks a better understanding of the physical and chemical limitations on the effectiveness of iron …

Characterization Of 1-Deoxy-D-Xylulose 5-Phosphate Reductoisomerase (Dxr) From Vibrio Vulnificus, Nikita K. Ussin

Theses and Dissertations

Vibrio vulnificus, a gram-negative bacterium, is the leading cause of seafood-borne illnesses and mortality in the United States. Previous studies of bacterial pathogens have identified a metabolite essential to V. vulnificus growth and function. 1-deoxy-D-xylulose 5-phosphate reductoisomerase (Dxr) is an essential enzyme in the viability of many bacteria and catalyzes the rearrangement of 1-deoxy-D-xylulose 5-phosphate (Dxp) to 2-C-methylerythritol 4-phosphate (MEP) within the MEP pathway found in plants and bacteria. Previous studies have been conducted to characterize Dxr homologs from other pathogens including E. coli, M. tuberculosis, and P. falciparum. Information on the structural and enzymatic characteristics of Dxr from Vibrio …

Properties And Applications Of Self-Assembled Benzophenone Bis-Urea Macrocycles, Arthur Ariston Korous

Theses and Dissertations

Supramolecular chemistry is a vast multidisciplinary field with great potential and application. It is driven by one simple concept, the self-assembly of small building blocks into larger complex architectures without application of external force. This thesis highlights previous applications of supramolecular chemistry in addition to new potential properties and applications. Recently, the Shimizu group reported a self-assembled benzophenone bis-urea macrocycle (host 1) that facilitated the selective oxidation of an encapsulated alkene when UV-irradiated in an oxygen atmosphere to afford products that are typically observed in radical mediated reactions.1 Surprisingly, the host displayed a stable room temperature radical upon UV irradiation. …

Classification Of Natural Phytoplankton Populations With Fluorescence Excitation-Based Imaging Multivariate Optical Computing, Shawna Kathleen Tazik

Theses and Dissertations

Phytoplankton account for the majority of the primary productivity in the ocean and contribute significantly to the global carbon cycle through photosynthesis. A quantitative characterization of phytoplankton cell size and taxonomic composition is essential for understanding marine biogeochemical cycles, quantifying carbon export, and for predicting the ocean’s response to future climate change. Our labs have developed a new instrument for this purpose that combines fluorescence excitation spectroscopy with an all-optical approach to multivariate statistics called multivariate optical computing (MOC). The instrument, known as the Shipboard Streak Imaging Multivariate Optical Computing (SSIMOC) photometer, is a simple filter photometer that images the …

From Model Systems To Real Catalysts: Bridging The Pressure And Materials Gaps, Audrey S. Duke

Theses and Dissertations

For decades a fundamental understanding of heterogeneous catalysts has been pursued for rational catalyst design using model systems under ultrahigh vacuum (UHV) conditions; however, there exist stark differences between the simplified models investigated under UHV and the industrial catalysts used at high pressures. To bridge these gaps, it becomes essential to utilize progressively more complex materials and to correlate their surface structure and activity using incrementally higher pressure techniques. In this work, both model Pt-Re catalysts and powdered metal-organic frameworks (MOFs) were studied using a suite of traditional UHV surface science techniques in addition to ambient pressure X-ray photoelectron spectroscopy …

Synthesis And Utility Of Bis-Urea Macrocycles As Nanoreactors And As Ligands For Metal Organic Materials, Sahan R. Salpage

Theses and Dissertations

“Supramolecular chemistry” powered by non-covalent interactive forces forms the crux in the area of host-guest chemistry. Supramolecular assemblies often have different chemical and physical properties than that of its individual molecular entities and are used to develop novel functional materials. Our expertise involves making functional materials from macrocycles, which contain two urea groups and two rigid C shaped spacer groups. These individual macrocyclic components can self-assemble through hydrogen bonding and other non-covalent interactions to form porous supramolecular assemblies that can be used as confined reaction environments and as ligands to synthesize novel metal organic materials.

This dissertation focuses on studying …

Crystal Growth And Characterization Of Reduced Early Transition Metal Compounds Grown Via Hydrothermal And Molten Flux Methods, Anthony J. Cortese

Theses and Dissertations

Interest in new and facile ways to prepare early transition metal reduced oxides has recently been increasing. In the past difficult flux techniques involving vacuum furnaces, expensive metal tubing, complicated electrolytic reduction apparatuses, were used to achieve in situ reduction of fully oxidized transition metal precursors. Often times these techniques were coupled with use of a difficult flux, such as boric acid, which is hard to remove due to its insolubility in water at room temperature. These limitations can be circumvented in multiple ways, including carefully choosing a redox neutral flux, using evacuated fused silica tubes for reaction vessels, and …

Mass Spectrometry-Based Protein Profiling And Investigations Of Tgf-Ss1-Induced Epithelial-Mesenchymal Transition Signatures In Namru Murine Mammary Gland Epithelial Cells, Matsepo Ramaboli

Theses and Dissertations

Breast cancer is the second-most common cancer and the second-leading cause of cancer-related deaths in women. Despite advances in cancer early detection, prevention and treatment, breast cancer is still a major health challenge due to low survival caused by breast cancer metastasis. This warrants critical attention and intervention. From the proteomic standpoint, a protein-based multiplex system that provides large array of informative signals for cancer identification and prognosis is still limited. In this dissertation work, we developed two mass spectrometry-based strategies involving chemical biology tools for rapid protein fingerprinting of breast cancer cell lines, and for probing the O-linked N-acetylglucosamine …

Applications Of Disposable Pipette Technologies With Lc-Ms/Ms For Forensic And Clinical Analyses Of Biological Matrices, Kaylee R. Mastrianni

Theses and Dissertations

Efficiently hydrolyzing glucuronide metabolites is an important step in the analysis of drugs in urine. Amitriptyline and cyclobenzaprine are both tricyclic compounds with tertiary aliphatic amine groups that are subsequently metabolized to a less common form of glucuronide metabolite, quaternary ammonium linked glucuronides (N+- glucuronide). A collaborative study was conducted to investigate discrepancies in recoveries of these two commonly prescribed compounds in patient urine samples when hydrolyzed with different enzyme from four different commercially available β-glucuronidase sources.

Similarly, there is potential for 6-monoacetylmorphine to be converted to morphine during β-glucuronidase hydrolysis of urine samples. 6-monoacetylmorphine is a unique metabolite of …

Ligand Engineering For Advanced Functional Composite Materials, Michael H. Bell

Theses and Dissertations

The surface modification of solid inorganic substrates for thermodynamic compatibility with organic polymer media has become an important area of study for the development of advanced functional composite materials. Polymer ligands covalently bound to the substrate surface have been an effective means to achieve said compatibility. Current investigations focus on multifunctional ligand engineering where multiple chemically distinct species, each with specific functionality, can be implemented on the filler surface simultaneously. A combination of matrix compatible polymer brushes and conjugated charge trapping moieties attached to filler surfaces are investigated for enhancements in dielectric properties. Presented herein are the synthesis and characterization …

Estimation Of The Quantum Effects Of Nuclei In Large Molecular Systems, Bing Gu

Theses and Dissertations

Chemical dynamics, in principle, should be understood by solving the time-dependent Schrödinger equation for a molecular system, describing motion of the nuclei and electrons. However, the computational efforts to solve this partial second-order differential equation scales exponentially with the system size, which prevents us from getting exact numerical solutions for systems larger than 4-5 atoms. Thus, approximations simplifying the picture are necessary. The so-called Born-Oppenheimer approximation, separating motion of the electrons and nuclei is the central one: solution to the electronic Schrödinger equation defines the potential energy surface on which the nuclear motion unfolds, and there are standard quantum chemistry …

Investigating Cross Talk Between The High And Low Iron Sensors In Saccharomyces Cerevisiae, John S. Hepburn

Theses and Dissertations

Iron is essential for nearly all life on earth. Cells must maintain sufficient levels of this important nutrient due its function as a central co-factor for many cellular processes. Although iron is extremely plentiful, its poor solubility requires specialized import. On the other side, too much iron inside the cell can lead to the generation of reactive oxygen species (ROS), which have deleterious effects on many cellular functions and have been implicated in a wide variety of diseases such as cancer and Alzheimer’s disease. Using the model eukaryote Saccharomyces cerevisiae, or budding yeast, our research group has accomplished much in …

Development Of Reactions And Methods For Labeling Biomolecules In Cells, Enoch Agbesi Adogla

Theses and Dissertations

The complexity of cellular environments presents a challenge to efforts at studying and elucidating biomolecules in cells. Covalent ligation of biomolecules with fluorescent molecules that have a reactive functional group that can react with a complementary functional group on biomolecules is one way that has been utilized to study biomolecules. It enables visualization and tracking of ligation and transportation of molecules within the cell. However, the myriad of functional groups within the cell makes achieving selectivity difficult. To circumvent this problem, reactions that do not interfere with biology have been developed. These reactions, referred to as bioorthogonal reactions must be …

Cobaltocenium Containing Polymers: Complexation With Organic Anion And Initial Assesment For Anion Exchange Membranes, Mohammad Pabel Kabir

Theses and Dissertations

In this thesis, cobaltocenium containing monomers and polymers are investigated for guest anion loading and alkaline anion exchange membrane for fuel cells. The properties of these polymers are characterized and discussed.

Chapter 1 describes overall background and potential applications of metallocene and metallocenium containing polymers. The research objectives of metallocenium containing polymers are discussed.

Cobaltocenium containing polymers have potential applications in biomedical science. Therefore, the effect of different parameters such as electrostatic charge, size, conformation, π-electron system and hydrogen bonding on the interactions between these polymers and small anionic probes has been studied qualitatively, as described in Chapter 2. A …

The Development Of A Miniature Spatial Heterodyne Raman Spectrometer For Applications In Planetary Exploration And Other Extreme Environments, Patrick Doyle Barnett

Theses and Dissertations

Space exploration is arguably one of the most important endeavors our species has ever undertaken. Rapid advances in rocketry and robotics in recent years has allowed for positioning of complex scientific instruments on other planets with a precision that was previously thought impossible. This, along with the need for more sophisticated chemical measurements to achieve the goals of new, more ambitious missions and recent advances in in-situ and remote spectroscopic techniques, has led to a boom in the use of spectroscopic instruments for space exploration. However, future missions to the moons of Jupiter and Saturn, along with other planetary bodies …

Using Synthetic Lectins To Investigate Metastatic Potential In Colon Cancer, Erin E. Gatrone

Theses and Dissertations

Cancer is a disease that affects millions of people each year and it is well established that early diagnosis is a key factor towards improving survival rate, with that in mind there is a great need for better diagnostics. From the earliest onset of cancer, changes can be detected in the type and amount of carbohydrates expressed by the cancer cells, i.e., aberrant glycosylation. This process results in differing glycosylation patterns that can be used to detect cancer. Aberrant glycosylation can also greatly affect the potential of cancer cells to metastasize and can be used to stage the disease as …

Issues In Laser Induced Breakdown Spectroscopy For Measurements In The Deep Ocean And Other High-Pressure Environments, Joseph C. Bonvallet

Theses and Dissertations

This dissertation describes fundamental and applied studies that have advanced the understanding and application laser induced breakdown spectroscopy (LIBS) to the deep-ocean environment and to operation on a deep-ocean submersible. Chapter one is an overview of LIBS including a brief history, LIBS theory, the instrumentation typically used, and a specific application. Chapter two analyzes the effect that monodisperse suspended particles have on LIBS emission intensity and on the formation of a LIBS plasma. This chapter demonstrates that for particle concentrations similar to those found in the neutrally buoyant regions around hydrothermal vents there is little effect on the LIBS emission …

Development Of Protein-Polymer Core-Shell Nanoparticles (Ppcs-Nps) As Efficient Vehicles To Deliver Therapeutic Agents Across Blood Brain Barrier (Bbb), Napat Tandikul

Theses and Dissertations

Blood Brain Barrier (BBB) plays a main role as selective barrier which controls and limits access of chemicals, molecules and therapeutic agents from blood to brain. The BBB endothelial cells are connected by Tight Junctions (TJs) which close intracellular spaces between the endothelial cells and block the free diffusion of substances, therefore many potential drugs for treating human brain diseases cannot reach the brain in sufficient concentration. Recently, many studies have thrown an interest in development of nanoparticles for delivering drugs and imaging agents across BBB. Our research group has developed protein-polymer core-shell nanoparticles (PPCS-NPs) which demonstrate great potential for …

Wide Field Measurements Using A Spatial Heterodyne Raman Spectrometer For Transmission Raman Spectroscopy And Standoff Detection, Kimberly A. Fessler

Theses and Dissertations

Our group recently developed a new type of Fourier transform Raman spectrometer, the spatial heterodyne Raman spectrometer (SHRS), for planetary exploration. The SHRS is a high spectral resolution, high throughput, compact dispersive interferometer, similar in design to a Michelson interferometer, where the mirrors are replaced by stationary diffraction gratings. The SHRS has no moving parts and does not require an entrance slit, making the throughput of the system orders of magnitude larger than a typical dispersive spectrometer. The wide field-of-view (FOV) of the SHRS enables wide area measurements without loss of sensitivity or spectral resolution and offers advantages such as …

Cdk8 And Cdk19 As Novel Regulators Of Bmp4 Induced Emt In Cancer, Anne Elizabeth Serrao

Theses and Dissertations

Bone morphogenetic protein 2/4 (BMP2/4), members of the transforming growth factor β (Tgf-β) superfamily, play a dichotomous role in the progression of cancers through cell growth suppression and the enhancement of tumorigenesis in a variety of cancers. Cyclin dependent kinase 8 (CDK8), a protein kinase that regulates gene transcription, is involved in a variety of cancers including breast and pancreatic cancers as well as in mediating BMP2 signaling via its canonical Smad1 pathway. Our studies show that BMP4 induced EMT signals primarily though Smad1 and that Yap1, a transcriptional co-activator, is necessary for BMP4 induced EMT. Using a highly specific …

Investigating Structure-Activity Relationships Of Sl11 To Develop A Better Prostate Cancer Diagnostic, Rong Huang

Theses and Dissertations

Prostate cancer is now the second leading cause of cancer death in American men. Since many of the diagnostics either have high false results or risky, it’s important to have better diagnostics and earlier diagnosis of prostate cancer. Aberrant glycosylation is a hallmark of cancer. When cancer occurs, aberrant glycosylation occurs, therefore, glycosylation patterns may provide information about different cancer types and metastatic potential. In order to study and use these glycosylation patterns, the boronic acid functionalized synthetic lectins that can interact with glycans have been developed. The work described here focuses on 1) the structure activities of synthetic lectins …

Improved Systems For On-Site Raman Measurements, William Joshua Huntington

Theses and Dissertations

The need to development lightweight miniature sensors for spectrometers for use in hazardous environments such as war zones, industrial settings, and space exploration is ever growing. This thesis will present studies aimed at improving Raman instruments for such applications by reducing the size, weight, and power consumption of the instrument. The two methods described here include the utilization of a light emitting diode (LED) source for Raman spectroscopy and a new type of Raman gas sensor.

Chapter one describes a new Raman spectrometer that utilizes an LED for Raman excitation coupled to the SHRS. LEDs are highly divergent broadband , …

Mechanistic Investigation And Potential Application Of A Fatty Acid Decarboxylating Cytochrome P450 Peroxygenase, Chun H. Hsieh

Theses and Dissertations

OleT (CYP152L1) is a recently discovered cytochrome P450 that is structurally similar to peroxide dependent P450s that catalyze fatty acid hydroxylations. OleT has been shown to catalyze the cleavage of n chain length fatty acids to form n-1 alkenes through C-C bond scission of the terminal carboxylate. Using headspace GC-MS and FTIR with isotopically labeled substrates, we have confirmed that OleT metabolizes eicosanoic acid to 1-nonadecene, forming carbon dioxide (CO2) as a co-product of the reaction. No oxygen deriving from peroxide is observed in either product. In order to probe the mechanistic deviation of OleT from P450 peroxygenases, we have …