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Full-Text Articles in Chemistry

Studies Of The Stability And Potential Applications Of Pyrrolidinofullerenes And Other Fullerene Derivatives, Olena Lukoyanova Dec 2007

Studies Of The Stability And Potential Applications Of Pyrrolidinofullerenes And Other Fullerene Derivatives, Olena Lukoyanova

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Over the last decade, the variety of chemically modified fullerenes and their potential applications has increased significantly. Among fullerene derivatives, pyrrolidinofullerenes are one of the most widely synthesized types since they can be easily and efficiently obtained via simple reactions from both empty and endohedral fullerenes. Although fullerenes in general and pyrrolidinofullerenes in particular have been considered for numerous applications in electronic and optoelectronic devices, photovoltaics, medicinal chemistry, etc., their potential application in the evolving field of molecular electronics has not been extensively explored. The envisioned role of the fullerenes usually involves storage or transport of electrons. Therefore, studies of …


Development Of Fullerene Based Sturctures For Photovoltaic And Electronic Applications, Amit Palkar Dec 2007

Development Of Fullerene Based Sturctures For Photovoltaic And Electronic Applications, Amit Palkar

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Solar energy can be envisioned as a long term alternative to rapidly depleting fossil fuels. The energy from the sun can be harnessed by constructing donor-acceptor (D-A) type devices where the incident photon induces the transfer of an electron from the donor to the acceptor. If recombination is prevented, this electron can then be channeled through an external circuit, thus leading to the generation of photocurrent. Porphyrins, which are the naturally occurring pigments in photosynthesis, have been widely established as donors while fullerenes, such as C60 and C70 , due to their unique electron accepting properties, have been …


Lithium-Conducting Ionic Melt Electrolytes From Oligomeric Ethylene Glycols: Synthesis And Characterization, Boutros Hallac Dec 2007

Lithium-Conducting Ionic Melt Electrolytes From Oligomeric Ethylene Glycols: Synthesis And Characterization, Boutros Hallac

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Commercial lithium ion cells consist of electrolytes that undergo salt concentration polarization which is acute upon high discharge currents. This type of polarization occurs as a result of the mobility of more than one ionic species in the presence of an electric field. One way to overcome it is by employing a material that would allow the mobility of one ionic species. This thesis will describe the synthesis and characterization of several fluorosulfonimide and fluorosulfonate based ionic liquids/melts as electrolytes having lithium as the only mobile ion. These materials were prepared by the nucleophilic addition reaction of a deprotonated polyether …


Thermodynaimic Study Of Nucleic Acids Recognition By Aminoglycosides , Hongjuan Xi Dec 2007

Thermodynaimic Study Of Nucleic Acids Recognition By Aminoglycosides , Hongjuan Xi

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ABSTRACT


Since the origin of first aminoglycosides antibiotics, streptomycin, isolated by Selman Waksman about 60 years ago, a number of aminoglycosides antibiotics were discovered to treat different infections. Neomycin class aminoglycosides were found to originally target the A site 16S rRNA in the 30S subunit of the ribosome within the Gram-negative bacteria. In addition to its antibacterial effect, aminoglycosides were also found to binding to various other viral RNA structures such as TAR and RRE of HIV, Group I introns and hammerhead ribozyme, implying its potential to be used as antiviral reagent.

Furthermore, previous studies in our laboratory discovered a …


Post-Production Separation And Functionalization Of Single-Walled Carbon Nanotubes, Kurukulasuriya Fernando Aug 2007

Post-Production Separation And Functionalization Of Single-Walled Carbon Nanotubes, Kurukulasuriya Fernando

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ABSTRACT
Single-walled carbon nanotubes (SWNTs) are considered to have many potential applications due to their unique structural, physical, chemical and electronic properties. Because the rigid structure of carbon nanotube determines its toughness in dissolution, the processing capability of carbon nanotube is strongly limited. My carbon nanotube functionalization research was mainly focused on developing innovative methods to functionalize nanotubes with various polymers and large aromatic molecules to make them soluble to study their interesting properties and applications. In this dissertation, different methods for the functionalization and solubilization of carbon nanotubes are described. The co-existence of metallic and semiconducting carbon nanotubes has …


Mixed Quantum-Classical Molecular Dynamics Study Of A Hydrated Electron And An Investigation Of Temperature Control Algorithms, Janet Aremu-Cole Aug 2007

Mixed Quantum-Classical Molecular Dynamics Study Of A Hydrated Electron And An Investigation Of Temperature Control Algorithms, Janet Aremu-Cole

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The use of classical and quantum mechanics has been employed in this dissertation to study temperature control algorithms and a hydrated electron. A comparison of the effects of four commonly used temperature control algorithms on the energetics and dynamics of liquid water has been executed, in efforts to better understand the non-equipartitioning effects caused by some thermostats. The Berendsen, Andersen, Langevin, and velocity rescaling temperature control algorithms were applied to both dimer and bulk water systems, using the TIP4P water model. The two deterministic thermostats, Berendsen and velocity rescaling, display the 'flying ice cube effect' that had been noticed earlier …


Synthesis, Reactions, And Applications Of Bis-Ortho-Diynyl Arene (Boda) Monomers, Polymers, And Derivatives, Mark Perpall May 2007

Synthesis, Reactions, And Applications Of Bis-Ortho-Diynyl Arene (Boda) Monomers, Polymers, And Derivatives, Mark Perpall

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Bis-ortho-diynyl arenes (BODA) monomers contain two arenediyne functional groups with variable functionality at both the linker group, X, and the alkyne terminal group, R. These arenediyne moieties undergo thermal Bergman reactions to cycloaromatize to naphthyl diradical species. The inclusion of two of these arenediyne functionalities allows the polymer to grow without losing processability and solubility as most aromatic polymers do. The second functionality acts as a solubilizing group until all functionalities are consumed in the fully cured network polymer.
When heated above 800 °C, BODA polymer converts to a high-yield glassy carbon material. This work has been extended …


Exploratory Synthesis And Characterization Of New Mixed-Framework Chalcohalides And Oxyhalide And Its Potential Applications For Diluted Magnetic Semiconductor, Lei Wang May 2007

Exploratory Synthesis And Characterization Of New Mixed-Framework Chalcohalides And Oxyhalide And Its Potential Applications For Diluted Magnetic Semiconductor, Lei Wang

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Due to the excellent diverse properties and performance, solid-state material with low-dimensional crystal structure has always been interested by solid-state scientists. Besides the interesting properties, the low-dimensional-structured materials are used as the platform for further research and application of semiconductor and optical devices, as well as theoretic studies. My dissertation research mainly focuses on two aspects: discovery of solids with low-dimensional crystal structure; fabrication and investigation of new materials using the discovered materials as the platform.
The idea of mixed-anion-framework has been used in synthesis of novel low-dimensional-structured solid-state materials. The stereo-active Sb3+/Bi3+ chalcogenides building units and …


Hydrothermal Crystal Growth Of Oxides For Optical Applications, Colin Mcmillen May 2007

Hydrothermal Crystal Growth Of Oxides For Optical Applications, Colin Mcmillen

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There is great interest in obtaining coherent radiation in all regions of the optical spectrum. This dissertation explores the hydrothermal growth of crystals that function in two regions currently inaccessible by solid state devices. The first gap exists in the deep-UV region, particularly below 200 nm. Some materials such as LBO and BBO can generate coherent light at wavelengths as low as 205 nm. The growth of these materials was explored to investigate the feasibility of the hydrothermal method as a new technique for growing these crystals. Particular attention was paid to the descriptive chemistry surrounding these systems, and several …


Adaptive Treatment Of Van Der Waals Interactions In Empirical Bond-Order Potentials With Application To Junction Formation In Carbon Nanotubes, Aibing Liu May 2007

Adaptive Treatment Of Van Der Waals Interactions In Empirical Bond-Order Potentials With Application To Junction Formation In Carbon Nanotubes, Aibing Liu

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Molecular dynamics (MD) simulation of reactive condensed-phase hydrocarbon systems is a challenging research area. The AIREBO potential is particularly useful in this area because it can simulate bond breaking and bond forming during chemical reactions. It also includes non-bonded interactions for systems with significant intermolecular interactions.

The first part of this dissertation describes a method to adaptively incorporate van der Waals interaction of carbon atoms into the AIREBO force field. In bond-order potentials, the covalent bonding interactions adapt to the local chemical environment, allowing bonded interactions to change in response to local chemical changes.
Non-bonded interactions should adjust to their …


The Glow Discharge - A Multifaceted Optical Emission Source: From Solids Analysis To Metalloproteins, Timothy Brewer May 2007

The Glow Discharge - A Multifaceted Optical Emission Source: From Solids Analysis To Metalloproteins, Timothy Brewer

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Glow discharges (GD) are well known for their application to direct solids elemental analysis of metals and alloys by optical emission spectroscopy (GD-OES). The most successful application of GD-OES has been the analysis of solid materials since the GD provides rapid, direct bulk and depth profiling analysis of solids, metals, powders, polymers, glasses and ceramics. However, solids analysis has typically suffered from the lack of true analytical blanks and the inability to study particulate solids in their native state. An approach for the analysis of solid powdered material entrapped in a sol-gel matrix by radio frequency glow discharge optical emission …


Functionalized Nanomaterials: Synthesis, Characterization, And Applications, Liangwei Qu May 2007

Functionalized Nanomaterials: Synthesis, Characterization, And Applications, Liangwei Qu

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Due to their unique electronic, optical, catalytic and mechanical properties, nanomaterials (nanoparticles and nanotubes) have been attracting much attention over the past decades. In this dissertation, polymeric nanoparticles bearing derivatized D-mannose and galactose molecules were prepared via dispersion polymerization and their interactions with various bacterial cells were studied. The results show that there are strong adhesin-specific interactions of the nanoparticles with E. coli cells, resulting significant nanoparticles-madiated cell agglutination.
Poly(ethylene glycol)-coated magnetic polymer nanoparticles were synthesized through miniemulsion polymerization by using macromonomer as both a comonomer and a surfactant. The resulting magnetic polymer nanoparticles were successfully used for bio-detection and …