Physical Sciences and Mathematics Commons^™

Mechanistic Studies Of Bimolecular Electron Transfer Self-Exchange Rates Of Ruthenium Ammine Pyridyl Complexes Measured By Nmr Line Broadening Techniques, Yishun Qin

Master's Theses

The electron transfer (ET) self-exchange rates on a series of complexes of (NH₃)₅Ru^II/III L^2+/3+ in D₂O (where L is a substituted pyridyl ligand) were investigated by dynamic NMR measurements. Significant rate enhancement was observed for the cases of L = 3-phenylpyridine and 4-phenylpridine due to possible π-π stacking between Phpy ligands. These observations matche well with recent stopped-flow work by Mehmood on a similar set of related pseudo-self exchange reactions. Kinetics of the (NH₃)₅Ru^II/III (3-trifluoromethylpyridine)^2+/3+ self-exchange reactions with addition of various simple/complex salts and hexacyano salts …

Phase Behavior And Rheology Of Latex, Thickener, Surfactant Mixtures And Liquid Crystal Based Compositions For Printing High-Efficiency Flexible Electronics, Franceska Anna Santos

Master's Theses

This project consists of two parts. One area of focus in the first part is understanding the interactions between a non-ionic, block copolymer type dispersant and hydrophobically-modified, ethoxylated urethane (HEUR) associative thickeners in water. The dispersant was mixed at various concentrations (0-2% by weight) with HEUR thickeners at 1% by weight concentration in the aqueous medium. This study is an integral part of our attempts to determine mechanisms of viscosity drop when colorant dispersions are added to latex tint base formulations thickened with associative thickeners. One of the HEUR thickeners is a product that has been available for over three …

The Influence Of Hydrogeomorphology, Soil Redox Conditions, And Salinity On The Spatial Zoning Of Saltgrass, Salt Rush, And Cattails In Scotts Creek Marsh, Swanton Pacific Ranch, Ca, Mark D. Gormley

Master's Theses

Scotts Creek Marsh (SCM) is a small coastal wetland ecosystem in Davenport, CA. The vegetation of SCM is dominated by three halophytic zones comprised of saltgrass, salt rush, cattails. The objectives of the study were (i) to investigate the variables that influence the zoning of the three dominant halophyte communities in SCM and (ii) to the test the effectiveness of Indicator of Reduction in Soil (IRIS) tubes to indicate the reduction of S. The study examined the following parameters from April 6 to July 21, 2013: (i) the HGM of Scotts Creek Marsh, (ii) soil oxidation and reduction (redox) conditions, …

Nanoparticles And Polymer Crystallization Kinetics In Hybrid Electronic Devices, Taylor William Wagner

Master's Theses

Conjugated semi-conducting polymers have become well known for their potential applications in hybrid electronic devices like solar cells, LEDs, and organic displays. These hybrid devices also contain inorganic nanoparticles, which complement the polymer when they are combined into the same layer. Control over the conformation and crystallinity of the polymer is critical for device performance, yet not much is known about the effect that these nanoparticles have on the polymer. Here, zinc oxide nanowire was surface modified with mono-substituted-carboxylic acid tetraphenylporphyrin and dodecanethiol, and introduced to poly(3-hexyl thiophene) in solution. The electron transfer, kinetics, and thermodynamics of this system were …

Lipid Production By Microalgae Treating Municipal Wastewater, James Edward Kelley

Master's Theses

Microalgae hold much promise as a feedstock in liquid biofuel production. Lipid content of microalgae cells range from 30-80% dry weight of biomass. It is projected that microalgae can produce between 1,000-6,500 gallons/acre/year of oil. Currently, production of industrial algae operates in open raceway ponds that use minimal capital and energy inputs to culture algae. Raceway ponds can also be used to grow microalgae from municipal waste streams. Although high biomass productivity can be achieved in these systems, there remains a large production gap between large volumes of biomass cultivation and high lipid content from microalgae cells. Low lipid content …

Formulation Development Of A Polymer-Drug Matrix With A Controlled Release Profile For The Treatment Of Glaucoma, Eric W. Tsoi

Master's Theses

Glaucoma is the leading cause of blindness in the United States accounting for 9-12% of all cases of blindness. Currently, the front line treatment for glaucoma are prostaglandins that may have to be taken up to several times a day. Even with proper treatment, roughly 11% of the patients using the treatment are non-compliant and lose their vision. In this project, ForSight Laboratories has developed a pharmaceutical drug delivering implant with the capability of sustaining long-term release of a prostaglandin as a new way to treat the condition. This project reports the product development of a polymer drug matrix with …

Morphology And Conformation Of Polythiophene Derivatives In Anisotropic Core-Shell Nanocomposites And Solution, Neil Redeker

Master's Theses

Conjugated semiconducting polymers have garnered substantial interest in recent years due to the potential for use in various applications, particularly in the field of electronic devices such as photovoltaic cells and light emitting diodes. Conjugated polymers offer numerous advantages in these applications, including low cost and high flexibility, but electronic devices based on these materials are currently limited by poor performance. Because of these limitations, increased focus has been placed on improving conjugated polymers for use in commercially viable products. Here, a novel core shell hybrid nanocomposite based on anisotropic zinc oxide nanowires and a side-chain functionalized polythiophene is reported. …

Latent Cysteine Residues From Polymers Prepared Via Free And Controlled Radical Polymerizations, Douglas Vincent Amato

Master's Theses

One less commonly used “click” reaction is thiazolidine chemistry. Thiazolidine chemistry is a commonly used reaction used in biological systems because the reaction requires the presence of both cysteine (a common amino acid) and an aldehyde or ketone. If cysteine residues could be incorporated into a polymer then a variety of applications could be developed. Polymers containing free thiols (aka thiomers) have developed in the last decade to become great mucoadhesives. If there was a facile route to control the amount of free thiols along the polymer then more fine-tuned and potentially stronger adhesives could be made. For these reasons …

Re-Healable Coating Based Upon Thermally Responsive Linkages, Dahlia Ningrum Amato

Master's Theses

The goal of this thesis was to design thermally responsive polyol resins that would be compatible with isocyanates. Two approaches were made to reach this goal, the first involved functionalizing soybean oil and the second involved post-polymerization modification of a methacrylate based resin.

A soybean based coating with thermally responsive Diels-Alder linkages has been prepared following an automotive two-component formulation. The resulting coatings displayed the capability to be healed following physical deformation by a thermal stimulus, and such a material has significant potential for end users. Various curing agents were employed, and resulted in variation of scratch resistance and re-healablity. …

Photoionization Mass Spectrometry And Photoelectron-Photoion Coincidence (Pepico) Spectroscopy Studies Of Select Biofuel Molecules, Joseph G. Czekner

Master's Theses

This thesis is the culmination of numerous experiments, performed on two different continents, investigating the spectroscopic and thermodynamic properties of several biofuels and fuel additives. It will start with an introduction about the motivation behind these experiments. The second chapter will outline the experimental details of the apparatus at the Advanced Light Source (ALS) in Berkeley, CA, followed by the Swiss Light Source (SLS) in Villigen, Switzerland. Third, the theoretical concepts and data analysis methods will be discussed in detail.

Chapter 4 will be the start of the newly obtained data. It presents some photoionization mass spectrometry studies on γ-valerolactone …

Surface Tethered Pamam Dendrimers On Controlled Pore Glass As Color Release Sensors For Phosphates, Chang Liu

Master's Theses

Poly(amidoamine) dendrimer (PAMAM) are highly branched macromolecules with reactive amine groups in their interior and exterior. PAMAM dendrimers were attached to controlled pore glass (CPG) surfaces in order to create new functionalized surfaces and used as platforms for UV-vis and fluorescent sensing of phosphate substrates via indicator displacement assays (IDA).

CPG surfaces were first modified with different sized PAMAM dendrimers (generation 3.0, 4.0, and 5.0), then reacted with two strong metal-chelators: aminofunctionalized terpyridine (synthesized from 2,2’:6’,2’’-terpyridine) and Nα-Nα-bis(carboxymethyl)-L-lysine (Lys-NTA). First of all, Cu(II) metal ion binding capacities were measured on the surfaces. Second, two terminal group density tests, amine assay …

Probing The Low Temperature Oxidation Of Furanic Biofuels, 2-Methyltetrahydrofuran And 2,5-Dimethylfuran, Utilizing Orthogonal Time-Of-Flight Mass Spectrometry Coupled To Synchrotron Radiation, Matthew Mcmanus

Master's Theses

Concern over natural resources and global climate shifts has increased the focus of sourcing transportation fuels from depleting oil wells to regenerative, biological based solutions. One avenue of biologically sourced fuel involves the extraction of C5 and C6 sugars from the woody, fibrous, and inedible plant materials, otherwise known as lignocellulosic biomass. These cellulosic sugars can be converted to target biofuels and biofuel additives like the furanic compounds, 2,5-dimethylfuran and 2-methylfuran. In this thesis, the low temperature oxidation of two compounds, 2,5-dimethylfuran and 2-methylfuran, are explored. These reactions were conducted at the Advanced Light Source in Berkeley, CA and used …

Comparison Of Liquid-Liquid Extraction And Solid Phase Extraction Of Mephedrone, Brittany Simone Love

Master's Theses

Legal high drugs are modified scheduled drugs. As with any new drug, researchers have to conduct studies to gather information about the drug. The problem with obtaining accurate information on new drugs is that by the time information is gathered, drug abusers and street chemists have developed new ones. Comparing designer drugs to their illegal counterparts is often helpful in that it can provide a starting point. Mephedrone is a new designer drug that has become a problem over the past few years. Often marketed as bath salts and plant food, mephedrone has become the knockoff replacement for amphetamines. This …

Growth And Carboxysome Composition Of The Csosia Pore Mutants Of Halothiobacillus Neapolitanus, Jenifer Milam

Master's Theses

Carboxysomes are specialized organelles that are filled with ribulose 1,5- bisphosphate carboxylase/oxygenase (RubisCO) needed for CO2 fixation. The major carboxysome shell proteins, CsoSl A, B, and C, form hexamers which tile together to form the facets of the thin shell. Each hexamer has a small central pore that may play a role in metabolite flux. Using predicted structural models, a specific amino acid within the conserved hexamer pore motif (Phe-Val-Gly-Gly-Gly-Tyr) was chosen to change the size and charge of the pore, respectively. Two mutants of Halothiobacillus neapolitanus were generated in which the wild type csoSJA gene was replaced with the …

Direct Chain-End Functionalization Of Living Polyisobutylene With Phenoxyalkyl(Meth)Acrylates, Conor Patrick Roche

Master's Theses

This volume describes efforts toward the synthesis and employment of phenoxyalkyl (meth)acrylates, which were used to end-quench 1sobutylene polymers m1tiated from 2-chloro-2,4,4-tnmethylpentane (TMPCl), and 5-tert-butyl-1 ,3-d1(1-chlorol- methylethyl)benzene (bDCC), respectively, at -70 °C in 40/60 (v/v) hexane/methyl chlonde. The quencher/cham end molar rat10s typically ranged from 2.5-4, while the ratio of Lewis ac1d/cham end was vaned from approximately 3 5-6 In all cases, alkylation occurred exclusively at the para position of the quencher and no cham degradat10n was observed, even at high concentrations of TiC14 and long reaction times. Prellmmary qualitative studies mvolved the reaction of quenchers of varymg alkyl tether …

Preparation Of Organofluorine Compounds: Exploring Mono-, Di-, And Tri-Fluorination, Diandra M. Rudzinski

Master's Theses

Organofluorine compounds exhibit biological activity and have advantageous properties for drug design. Natural occurring fluorinated molecules are rare, demanding new synthetic methods for their preparation. A novel route to access trifluoromethyl ketones from Weinreb amide precursors is discussed. This is the first documented method for the use of the Ruppert-Prakash reagent, (trifluoromethyl)trimethylsilane, for the production of trifluoromethyl ketones from amide starting materials. This method is tolerant of aryl and alkyl substrates exhibited by their moderate to excellent yields. A discussion of the unusual reactivity of these amides, their selectivity for mono-trifluoromethylation, and other mono-, and di-fluorination attempts are reported.