Chemistry Commons^™

Conversion Of Racemic Ibuprofen To (S)-Ibuprofen, David Chavez-Flores

Open Access Theses & Dissertations

Ibuprofen is a common Non-Steroidal Anti-Inflammatory Drug (NSAID) sold as a racemic or equal mixture of (R) and (S) mirror-image enantiomers. Without patent protection, ibuprofen is an orphan drug even though one enantiomer, (S)-ibuprofen, provides relief three times faster than its racemic mixture with fewer side effects. The goal of this research was to develop a facile, environmentally benign (no waste of ibuprofen or catalysts), and inexpensive process to convert a commercially available racemic mixture of ibuprofen to the therapeutically active (S)-ibuprofen.

After many attempts, the most successful conversion of racemic ibuprofen to (S)-ibuprofen was the in situ racemization and …

Titanium Niobium Nano Porous Materials: New Photocatalysts For Water Decontamination, Maryam Zarei Chaleshtori

Open Access Theses & Dissertations

Water pollution is major environmental problem worldwide. Many common industrial organic compounds that make their way into water systems can be carcinogenic at trace levels and are difficult and costly to remove completely with conventional technologies. Because of this, authorities and researchers are trying to improve current water cleanup techniques.

Heterogeneous photocatalysts that accelerate the photocatalytic destruction of organic contaminants in water are a potentially inexpensive and highly effective way to remove both trace-level and saturated harmful compounds from industrial waste streams and drinking water. Titanium dioxide has the potential to completely mineralize organic compounds in water under ultraviolet light. …

Development Of Nanotube Hexaniobate For Photocatalytic Production Of Hydrogen From Water, Saroja Pradhan

Open Access Theses & Dissertations

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Dissolution Of Chitosan In Ionic Liquids For Acylation Chemistry And Formation Of Cellulose-Chitosan Blends, Cristina Stefanescu

LSU Doctoral Dissertations

Dissolution of chitosan in ionic liquids was accomplished. It has been shown that 1-butyl-3-methylimidazolium acetate (BMIMAc) is a better solvent than 1-butyl-3-methylimidazolium chloride (BMIMCl). Dissolution of chitosan in BMIMCl required a prior regeneration of chitosan from 1% acetic acid solution. In the case of BMIMAc, both dried chitosan and regenerated chitosan from acetic acid solution have been dissolved in a relatively short amount of time. While concentrations up to 2 wt% of chitosan in BMIMCl could be obtained, concentrations of 10 wt % of chitosan in BMIMAc were realized. Homogeneous phthalation and benzoylation of chitosan were achieved in these ionic …

Iron (Iii) Oxide And Copper (Ii) Oxide Mediated Formation Of Pcdd/Fs From Thermal Degradation Of 2-Mcp And 1,2-Dcbz, Shadrack Kirwa Nganai

LSU Doctoral Dissertations

Formation of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) which occurs inexorably from most thermal and combustion processes constitutes a major toxic component of environmental pollutants. Generally, it is well established that transition metal-mediated reactions account for the majority of PCDD/F emissions from combustion sources. Specifically, both copper and iron ions, which occur abundantly in combustion generated particulate matter, are considered probably the most active in promoting PCDD/F formation typically in the low temperature post-combustion zone and flue gas pollution control devices. It has also been demonstrated that chlorinated phenols are key intermediates in essentially all pathways of PCDD/F formation. Chlorinated benzenes …

Energy Of The Conduction Band In Near Critical Point Fluids, Cherice M. Evans, G. L. Findley

Publications and Research

The study of the evolution of the conduction band in dense gases and supercritical fluids near the critical point has been complicated by a lack of precise experimental measurements. Both photoemission from an electrode immersed in the fluid and field ionization of a molecule doped into the fluid have been used to probe solvent density effects on the energy of an excess electron as a function of fluid number density and temperature. In this perspective, we present recent experimental results that show a strong critical point effect on the minimumconduction band energy near the critical density and temperature of a …

Computer Simulation Of Ion-Induced Nucleation In The Presence Of Single Ions And Ion Pairs, Samuel Keasler

LSU Doctoral Dissertations

Atmospheric aerosol particles play an important role in climate and human health. Despite their importance, the mechanisms of their formation are still poorly understood. Ion-induced nucleation may play a role in the process, but details are lacking about how the nucleation rate depends on the size, charge, and number of ions in the cluster. In order to better understand the role that ions might play in new particle formation, we have performed a series of AVUS-HR simulations of the water nucleation in the presence of both single ions and ion pairs. These simulations have shown that the location of the …

Investigations Of Structure / Property Interrelationships Of Organic Thin Films Using Scanning Probe Microscopy And Nanolithography, Zorabel Mallorca Lejeune

LSU Doctoral Dissertations

Studies of the surface assembly and molecular organization of organic thin films were studied using scanning probe microscopy (SPM) and scanning probe lithography (SPL). Systems of organic thin films such as n-alkanethiols and pyridyl functionalized porphyrins were characterized at the molecular level, and measurements of the conductive properties of polythiophenes containing in-chain cobaltabisdicarbollides were accomplished. Understanding the self-organization and mechanisms of self-assembly of organic molecules provides fundamental insight for structure/property interrelationships. Investigations of the surface assembly of 5,10-diphenyl-15,20-di-pyridin-4-yl-porphyrin (DPP) on Au(111) were done using SPL methods of nanoshaving and nanografting. Automated computer designs were developed for nanofabrication to provide local …

Microfluidic Devices Interfaced To Matrix-Assisted Laser Desorption/Ionization Mass Spectrometry For Proteomics, Jeonghoon Lee

LSU Doctoral Dissertations

Microfluidic interfaces were developed for off-line matrix-assisted laser desorption/ionization mass spectrometry (MALDI). Microfluidic interfaces allow samples to be manipulated on-chip and deposited onto a MALDI target plate for analysis. For this research, microfluidic culturing devices and automated digestion and deposition microfluidic chip platforms were developed for the identification of proteins. The microfluidic chip components were fabricated on a poly(methyl methacrylate), PMMA, wafer using the hot embossing method and a molding tool with structures prepared via micromilling. One of the most important components of the chip system was a trypsin microreactor. An open channel microreactor was constructed in a 100 µm …

Synthesis And Characterization Of Rare Earth-Nickel-Gallium Ternary Intermetallics, Kandace R. Thomas

LSU Doctoral Dissertations

The structural and physical characterization of several early and latter rare earth Ln-Ni-Ga systems, which include Ln2NiGa12 (Ln = Pr, Nd, Sm), alpha-LnNiGa4 (Ln = Y, Gd – Yb) and beta-LnNiGa4 (Ln = Tb – Ho) will be presented in this work. These systems are thermodynamically located within a copious, robust phase space and provide a rich understanding of how slight modifications to synthetic preparations can yield the adoption of different structure types in a Ga-rich regime. Each of these phases is made up of well-studied substructures which lend an additional angle of apperception as to how their structure and …

Highly Efficient Selection, Enumeration, Enrichment, And Molecular Profiling Of Low-Abundance Biological Cells, Udara R. Dharmasiri Rasika Dharmasiri

LSU Doctoral Dissertations

After brief overviews of low-abundance cell selection techniques in chapter 1 and circulating tumor cells in chapter 2, this dissertation initially focuses on the development of aptamer incorporated high-throughput microfluidic techniques to select rare circulation prostate cancer cells (LNCaP) directly from whole blood with subsequent quantification of these rare cells using a non-labeling approach. Then, I extended the technology to environmental samples in an effort around time, sensitivity, and portability of traditional groundwater assessment. As a model bio- pathogen, E. coli O157:H7 was chosen due to its toxicity and its adverse impact on recreational waters. Low-abundance (<100 cells mL-1) E. coli O157:H7 cells were isolated and enriched from environmental water samples using a microfluidic chip that its capture beds were covalently decorated with E.coli O157:H7 specific polyclonal antibodies. The selected cells were enumerated using RT-qPCR technique. Finally, I have integrated HTMSU with electrokinetic enrichment microfluidic unit for performance of single recombinant low-abundance CTC cell-based assay. A series of analytical processes were carried out, including immunoaffinity selection of rare CTCs, quantification of selected cells via conductivity impedance and electrophoretic enrichment of selected cells for PCR/LDR/CE interrogation for detection of low-abundance point mutations in genomic DNA.

Fabrication Of Receptor-Modified Microfluidic Surfaces For Applications In Glycoprotein Screening, Jennifer Macalindong De Guzman

LSU Doctoral Dissertations

Glycoproteins have long been identified to have a profound association with human pathological processes, and they are much sought after as potential biomarkers to aid in the early diagnosis and clinical prognosis of cancers and diseases. There is currently high demand for high-throughput and low–limit–of–detection techniques that can afford profiling of the glycoproteome. Micro-total analysis systems (µTAS) based on microfluidics have the potential to fulfill these requirements, but in order to reduce the complexity of the protein pool, the µTAS devices must contain a pre-isolation and enrichment component. The research project undertaken here involved derivatization of microfluidic …

Synthesis Of Aza-Bridged Tetraphosphine Ligands For A Dirhodium Hydroformylation Catalyst, Scott Michael Boudreaux

LSU Master's Theses

A novel tetraphosphine ligand rac-et,ph-P4 (et,ph-P4 = PEt2CH2CH2(Ph)PCH2P(Ph)CH2CH2PEt2) is used for the formation of a highly active and regioselective hydroformylation catalyst. The active catalytic species, Rh2H2(ƒÝ-CO)2(et,ph-P4)]2+, is formed in situ under H2/CO pressure. This is one of the most impressive examples of homobimetallic cooperativity in homogeneous catalysis. The fragmentation of this catalyst by CO has been investigated and confirmed by in situ NMR spectroscopic studies. A new tetraphosphine ligand rac-et,ph-P4-Ph (et,ph-P4-Ph = PEt2(o-C6H4)P(Ph)CH2(Ph)P(o-C6H4)PEt2) has been synthesized to combat this fragmentation problem. However, the inability to successfully separate the meso and racemic isomers of the ligand has led to more alteration …

Non-Portland Cement Activation Of Blast Furnace Slag, Anne Elizabeth Oberlink

University of Kentucky Master's Theses

The purpose of this project was to produce a “greener” cement from granulated ground blast furnace slag (GGBS) using non-Portland cement activation. By eventually developing “greener” cement, the ultimate goal of this research project would be to reduce the amount of Portland cement used in concrete, therefore reducing the amount of carbon dioxide emitted into the atmosphere during cement production.

This research studies the behavior of mineral binders that do not contain Portland cement but instead comprise GGBS activated by calcium compounds or fluidized bed combustion (FBC) bottom ash. The information described in this paper was collected from experiments including …

Design And Development Of Chiral And Achiral Molecularly Imprinted Stationary Phases, Jason Paul Lejeune

LSU Doctoral Dissertations

Although the cross-linker can comprise over 80% of the polymer composition, improving the nature of the cross-linker in molecularly imprinted polymers has not been studied extensively. The goal of this research is to develop novel cross-linking monomers to either use in the One MoNomer Molecularly Imprinted Polymer system (OMNiMIP) or use in conjunction with other commercially available cross-linkers and functional monomers. Chapter 2 contains research into the understanding of the performance of a new cross-linking monomer (N, O - bismethacryloyl ethanolamine, NOBE) discovered in the Spivak Research Group. The ability of this monomer to outperform traditional two monomer systems in …

Part I: Syntheses, Characterizations, And Investigations Of Molecular Micelles And Imidazolium-Based Ionic Liquids For Protein Separations In Electrophoresis Part Ii: Investigating The Mentoring Canon Through Exploration Of Thirty Years Of Mentoring By An Exemplar, Monica R. Sylvain

LSU Doctoral Dissertations

The research reported in this dissertation is presented in two parts. The first part is the Syntheses, Characterizations, and Investigations of Molecular Micelles and Imidazolium-Based Ionic Liquids for Protein Separations in Electrophoresis, and the second part is a case study entitled Investigating the Mentoring Canon through Exploration of Thirty Years of Mentoring by an Exemplar. Protein separations in the gel electrophoretic format are ubiquitous analyses used on a daily basis throughout biochemistry, analytical chemistry, and biotechnology. The goal of the research reported in the first part of this dissertation is to synthesize and characterize molecular micelles and ether-functionalized imidazolium-based ionic …

Particle Analysis In Infrared Laser Desorption And Ablation, Xing Fan

LSU Doctoral Dissertations

The fundamental physical processes of mid infrared laser ablation in the context of laser desorption mass spectrometry were investigated. Understanding the mechanisms of infrared laser desorption and ablation can lead to improvements in these techniques and expand their applications. Particles were generated from glycerol irradiated at atmospheric pressure using a tunable infrared laser at wavelengths between 2.6 and 3.8 µm. The wavelength dependence of size distributions of ablated particles was measured. The particle concentration roughly tracked the infrared absorption spectrum of glycerol and the mean particle size tracked the inverse of the IR absorption. A novel approach, post ablation particle …

A Study Of The Interactions Of Lipid Bilayers And Dendrimers Using Small Angle X-Ray Scattering And Freeze Fracture Transmission Electron Microscopy, Derek R. Dorman

LSU Doctoral Dissertations

Lipids are fundamental to all life forms, a key component of cell walls, and essential to proper respiratory function. They are amphiphilic molecules and readily form bilayers. Dendrimers are designer molecules that can be tailored to provide a variety of endgroup moieties, sizes, and charges. The interaction of liposomes and dendrimers can provide information on how medicine interacts with cells and an array of unique structures can be imagined from their assembly into superstructures. Polypropylenimine tetraamine (DAB-Am) and 1-directional arborol dendrimers have been studied in different molar concentrations with 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC) bilayers. One-directional arborols are amphiphilic dendrimers with a hydrophilic …

Stability Of Spore-Based Sensing Systems, Abhishek Sangal

University of Kentucky Master's Theses

The full exploitation of bacterial whole-cell biosensing systems in field applications requires the survival of bacterial cells and long term-preservation of their sensing ability during transportation and on-site storage of such analytical systems. Specifically, there is a need for rapid, simple and inexpensive biosensing systems for monitoring human health and the environment in remote areas which often suffer from harsh atmospheric conditions and inadequate commercial distribution and storage facilities. Our laboratory has previously reported the successful use of bacterial spores as vehicles for the long-term preservation and storage of whole-cell biosensing systems at room temperature.

In the present research, we …

Functionalization Of Multi-Walled Carbon Nanotubes And The Interactions Of Multi-Walled Carbon Nanotubes In Epoxy Composites, Christopher Fitzwater

University of Kentucky Master's Theses

Multi-walled carbon nanotubes (MWNTs) are a relatively new allotrope of carbon that have potentially useful properties that may improve polymer composites. The work of this thesis explores the interactions between MWNTs and functionalized MWNTs within epoxy matrix and the properties of the MWNT/epoxy composite. These interactions were characterized with an emphasis on finding how well the MWNT/epoxy composite flows and how conductive it is after curing.

Major Challenges For The Modern Chemistry In Particular And Science In General, Vuk Uskoković

Pharmacy Faculty Articles and Research

In the past few hundred years, science has exerted an enormous influence on the way the world appears to human observers. Despite phenomenal accomplishments of science, science nowadays faces numerous challenges that threaten its continued success. As scientific inventions become embedded within human societies, the challenges are further multiplied. In this critical review, some of the critical challenges for the field of modern chemistry are discussed, including: (a) interlinking theoretical knowledge and experimental approaches; (b) implementing the principles of sustainability at the roots of the chemical design; (c) defining science from a philosophical perspective that acknowledges both pragmatic and realistic …

Explorations In Homeoviscous Adaptation And Mass Spectral Analysis Of Membrane Lipids, Michael Douglas Timmons

University of Kentucky Doctoral Dissertations

The focus of this dissertation is centered on the mass spectral analysis of lipids and changes occurring in keeping with the concept of homeoviscous adaptation [1]. Homeoviscous adaptation is the process of modification of membrane lipids in response to environmental stimuli [1]. Dissertation investigations applied this concept to prokaryotic and eukaryotic organisms, and expanded the perception of environmental factors from exogenous organic solvents to intracellular environment.

The field of lipidomics deals with the analysis of phospholipid and fatty acid components of membranes the changes that occur due to environmental stimuli and their biological significance [2-6]. The high sensitivity of mass …

Studies Toward The Total Synthesis Of (±)-Α-Yohimbine By Double Annulation, Raghu Ram Chamala

University of Kentucky Doctoral Dissertations

The indole alkaloids, a class of natural products, have received much synthetic attention for years due to their diverse structures and interesting biological properties. We are particularly interested in synthesizing some of the yohimbine alkaloids extracted from the bark of a tall evergreen African tree (Corynanthe yohimbe, commonly known as fringe tree). Yohimbine and its stereoisomers have been tempting targets for synthetic organic chemists for more than fifty years. These compounds feature a pentacyclic ring system with two heteroatoms and five stereogenic centers.

Broadly, the fifteen different synthetic approaches that led to the successful completion of yohimbine alkaloids …