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Chemistry

Clemson University

All Dissertations

Theses/Dissertations

2011

Articles 1 - 11 of 11

Full-Text Articles in Physical Sciences and Mathematics

Single Particle And Ensemble Spectroscopy Of Conjugated Polymer Nanoparticles And Their Development For Photodynamic Therapy, Jennifer Grimland Dec 2011

Single Particle And Ensemble Spectroscopy Of Conjugated Polymer Nanoparticles And Their Development For Photodynamic Therapy, Jennifer Grimland

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Energy transport in conjugated polymers is the combination of energy transfer and exciton diffusion. There is considerable ongoing research in this field, converging to develop better organic photovoltaics, polymer light emitting diodes (PLEDs) and organic solar cells, to name a few. One way these phenomena can be explored is by doing solution dependent studies on conjugated polymer nanoparticles. With experiments on CP dots in an aqueous solution and the addition of a water miscible organic solvent in varying concentrations, dynamics occurring in the folding process can be better understood, and also exciton and fluorescence quenching properties can be extracted as …

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Electrolyte Incorporation Into Composite Electrodes For Proton-Exchange Membrane Fuel Cells And Lithium-Ion Batteries, Jung Oh Dec 2011

Electrolyte Incorporation Into Composite Electrodes For Proton-Exchange Membrane Fuel Cells And Lithium-Ion Batteries, Jung Oh

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This dissertation describes research on the preparation and characterization of composite electrodes for use in proton-exchange membrane (PEM) fuel cells and lithium ion batteries. The general focus of the research was on high-surface-area carbon supports for platinum catalysts in fuel cells, and integration of electrolytes, particularly fluoropolymer electrolytes, into composite electrodes both batteries and fuel cells. Results are described for work in the following three specific topical areas.
1. Carbon nanofibers for use as platinum (Pt) catalyst supports in fuel cells were prepared by carbonization of electrospun acrylic fibers. The resulting carbon nanofibers were found to contain mainly micropores. Following …

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Modification And Characterization Of Fluorescent Conjugated Polymer Nanoparticles For Single Molecule Detection, Yueli Zheng Dec 2011

Modification And Characterization Of Fluorescent Conjugated Polymer Nanoparticles For Single Molecule Detection, Yueli Zheng

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Single molecule tracking using fluorescent dye or nanoparticle labels has emerged as a useful technique for probing biomolecular processes. Considerable interest arises in the development of nanoparticle labels with brighter fluorescence in order to improve the spatial and temporal resolution of single molecule detection and to facilitate the application of single molecule detection methods to a wider range of intracellular processes. The McNeill laboratory recently reported that conjugated polymer nanoparticles exhibit fluorescence cross-sections roughly 10-100 times higher than other luminescent nanoparticles of similar size, excellent photostability (2.2×108 photons emitted per nanoparticle prior to photobleaching), and saturated emission rates roughly 100 …

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Semifluorinated Aromatic Ether Polymers Segmented With Polyethylene Glycol (Peg), Dakarai Brown Aug 2011

Semifluorinated Aromatic Ether Polymers Segmented With Polyethylene Glycol (Peg), Dakarai Brown

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Aromatic trifluorovinyl ether (TFVE) monomers are the precursors for perfluorocyclobutyl (PFCB) aryl ether polymers and fluoroethylene/vinylene alkyl/aryl ether (FAE) polymers. PFCB aryl ether polymers are prepared by 2π + 2π cycloaddition of aromatic TFVE monomers. FAE polymers are prepared by nucleophilic addition of dual functional aryl or alkyl alcohols to aryl TFVE monomers. PFCB aryl ether and FAE polymers are amorphous, have excellent processability, high thermal stability, optical clarity, and tunability using a variety of (co)monomers. In this dissertation several novel monomers, polymers, and blends were prepared by incorporation of polyethylene glycol (PEG) or PEG precursors.
Chapter 1 contains the …

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A Theoretical Investigation Examining Dna Conformational Changes And Their Effects On Glycosylase Function, Allyn Brice Aug 2011

A Theoretical Investigation Examining Dna Conformational Changes And Their Effects On Glycosylase Function, Allyn Brice

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Glycosylase enzymes initiate the process of base excision repair (BER) in order to prevent the irreversible modification of the genome. In the BER process a damaged DNA base is recognized, removed from the DNA sequence, and then the remaining abasic site is repaired. Glycosylase enzymes are responsible for the base recognition mechanism and catalysis of the base excision. One of the most studied glycosylase superfamilies is uracil DNA glycosylase (UDG). The UDG superfamily has demonstrated specificity for excising uracil, which is the deamination product of cytosine, from DNA sequences of prokaryotes and eukaryotes. Mismatch-specific uracil DNA glycosylase (MUG) is a …

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Bridging The Gap Between Structures And Properties: An Investigation And Evaluation Of Students' Representational Competence, Sonia Underwood Aug 2011

Bridging The Gap Between Structures And Properties: An Investigation And Evaluation Of Students' Representational Competence, Sonia Underwood

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The heart of learning chemistry is the ability to connect a compound's structure to its function; Lewis structures provide an essential link in this process. In many cases, their construction is taught using an algorithmic approach, containing a set of step-by-step rules. We believe that this approach is in direct conflict with the precepts of meaningful learning. From a sequential, mixed methods study, we found that students have much difficulty constructing these structures and that the step-by-step rules do not make use of students' relevant prior knowledge. This causes students to develop 'home grown' rules when unsure of how to …

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Conjugated Polymers And Inter-Chromophore Interactions: Synthesis, Photophysical Characterization And Application, Anshuman Mangalum Aug 2011

Conjugated Polymers And Inter-Chromophore Interactions: Synthesis, Photophysical Characterization And Application, Anshuman Mangalum

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Ever since the discovery of conducting polymers (CPs)in the late 1970s, organic conjugated materials and polymers is one of the most popular and fascinating research area among the scientists due to the remarkably unique properties and broad range of applications of (CPs), notably organic photovoltaic (OPVs), organic or polymer based light emitting devices (OLEDs / PLEDs), field effect transistors (FETs), nonlinear optical (NLO) devices and sensor for biologically relevant analytes, metal ions and anions. Optical properties of these materials depend on intra / interchromophoric interaction, geometry and relative orientation in space. Detailed study of such materials can also help us …

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Particle Beam Glow Discharge Spectroscopy As A Tool For Speciation And Metallomics Analysis, Charles Quarles Jr May 2011

Particle Beam Glow Discharge Spectroscopy As A Tool For Speciation And Metallomics Analysis, Charles Quarles Jr

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Metallomics is a growing field of interdisciplinary research that investigates metals in biological and environmental systems. One of the major problems in detecting metals in biological systems is the instrumentation required to analyze these complex biological samples. Typically, an inductively coupled plasma-optical emission spectrometer or -mass spectrometer (ICP - OES or - MS) is used for elemental analysis and an electrospray ionization-mass spectrometer (ESI-MS) is used for molecular information. In almost all cases, the sample introduction matrix is different for each instrument, which can affect the physiological conditions of the sample and change its properties. Particle beam/hollow cathode-optical emission spectroscopy …

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Synthesis, Characterization, And Reactivity Of Biologically Relevant Copper(I) Selone And Thione Complexes, Martin Kimani May 2011

Synthesis, Characterization, And Reactivity Of Biologically Relevant Copper(I) Selone And Thione Complexes, Martin Kimani

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In Fenton-like reactions, Cu+ localized on DNA reduces hydrogen peroxide to form hydroxyl radical (*OH), resulting in oxidative DNA damage. This DNA damage causes mutation and cell death, which can lead to diseases such as cancer, Alzheimer's, and arteriosclerosis. Sulfur and selenium antioxidants have been investigated for the prevention and treatment of these diseases, and studies have shown that sulfur- and selenium-containing antioxidants prevent DNA damage from copper-generated hydroxyl radical and that metal coordination is required for the observed antioxidant activity.
To determine how copper coordination results in DNA damage inhibition, Cu+ complexes with selone and thione ligands were synthesized …

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Targeting A-Form Nucleic Acids: A Neomycin Based Approach, Nicholas Shaw May 2011

Targeting A-Form Nucleic Acids: A Neomycin Based Approach, Nicholas Shaw

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This manuscript reflects our most recent advancements in the recognition of nucleic acids. Chapter one focuses on previously established methods in nucleic acid recognition. Nucleic acid targeting by small molecules affords a unique way to potentially inhibit biological functions, which is different from targeting enzyme and protein bio-macromolecules. We seek to further develop an aminoglycoside approach to targeting nucleic acids. Since aminoglycosides were first introduced, over 60 years ago, as treatment for tuberculosis, natural product discovery and demands for therapeutically more effective aminoglycosides, with lowered toxicity, have dominated the landscape of aminoglycoside research. More recently, our group has established neomycin …

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Synthesis And Characterization Of Extended Solids Containing Nano-Sized Transition Metal Oxide Lattices, Matthew Williams May 2011

Synthesis And Characterization Of Extended Solids Containing Nano-Sized Transition Metal Oxide Lattices, Matthew Williams

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In this research, focus has been placed on the study of magnetic anomalies due to geometric frustration of magnetic ions. The goal of the study presented in this dissertation was to synthesize pseudo&ndashlow&ndashdimensional (PLD) compounds, those structures showing zero (dot), one (chain), and two (sheet) dimensional lattices observed in extended (3D) host frameworks with enhanced anisotropic physical properties, in an attempt to elucidate some structure&ndashproperty correlations arising from magnetic spin confinement. The scope of this research involved 1) exploratory synthesis of novel, low&ndashdimensional transition metal oxide lattices, specifically Mn and V, embedded in non&ndashmagnetic oxyanion frameworks, either Ge, P, or …

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