Chemistry Commons^™

Nanodiamonds And Carbon Nano-Onions Ceramic Composites And Their Applications, Ibrahim Munkaila Abdullahi

Masters Theses

"Luminescent nanodiamonds are photostable non-blinking fluorescent biocompatible, non-toxic, functional Zable materials made from high-pressure high temperature (HPHT) microcrystalline diamonds. For long, the scientific community has been investigating for a clean, efficient and cost-effective technique to reduce the size of fluorescent microcrystalline diamond into nanodiamonds. Their color center, responsible for the fluorescent properties are crucial for their applications, including biomedical imaging, nano sensing, quantum computing etc, and therefore should not be affected significantly by the method of size reduction applied. A novel size reduction technique that is based on explosive fragmentation was developed and the corresponding fragmented diamonds obtained were characterized …

Removal Of Antimony And Bismuth From Copper Electrorefining Electrolyte By Two Proprietary Solvent Extraction Extractants, Andrew Artzer

Masters Theses

"Antimony and bismuth are two of the most problematic impurities in copper electrorefining (ER). Because of this, much research has been done investigating the ways to remove them. Processes that are currently being used industrially include anode additions, liberators, ion exchange (IX), and solvent extraction (SX). Of these, liberators and anode additions are the most common while SX is the least, mostly being used for arsenic removal. There are other methods that have been evaluated, but are not in commercial use. These include the use of various electrolyte additives, and adsorbents such as bentonite clay and heavy metal sulfates.

Two …

Research And Development Of Optically Transparent Join With Low Processing Temperatures, Eric Kevin Muskovin

Masters Theses

The purpose of this study was to investigate durable solar cell cover glass joins produced by diffusion bonding with deep eutectic solvents (DES) and to develop a novel process of joining optically transparent materials at low temperatures. A joined PV cell-glass specimen was characterized using Raman, μ-FTIR, SEM-EDS, and thin-film XRD. DESs were created with malonic acid (MAL) and choline chloride (ChCl) of varying composition factors (CF; CF=MAL/ChCl). Joining borosilicate glass coupons was attempted using DESs with CF = 0.65 and 1 at temperatures between 100-150 °C for 20 hours. Joining the glass coupons failed at all temperatures and oxygen …

In Situ Ph Determination Based On The Nmr Analysis Of ¹H-Nmr Signal Intensities And ¹⁹F-Nmr Chemical Shifts, Ming Huang

Masters Theses

"The pH of an NMR sample can be measured directly by NMR experiments of signal intensities, chemical shifts, or relaxation time constants that depend on the pH. The ¹H NMR peak intensities of the pH indicator phenolphthalein change as it changes from the OH-depleted form to the OH-rich form in the range of pH = 11.1 to 12.7. Because this range is rather small, another NMR technique was utilized based on ¹⁹F chemical shifts. The shift of F^- in an aqueous solution of NaF changes in the alkaline range between pH = 11.0 and 14.0 and even …

Tracking Silver, Gold, And Titanium Dioxide Nanoparticles Through Drinking Water Systems By Single Particle - Inductively Coupled Plasma - Mass Spectrometry, Ariel Renee Donovan

Masters Theses

"Single particle (SP)-ICP-MS methods were developed to characterize and quantify Ti-containing, titanium dioxide, silver, and gold NP concentration, size, size distribution and dissolved metal element concentration in surface water and treated drinking water. The effectiveness of conventional drinking water treatments (including lime softening, alum coagulation, filtration, and disinfection) to remove NPs from surface water was evaluated using six-gang stirrer jar test simulations. Six-gang stirrers were used to simulate drinking water treatments including lime softening, alum coagulation, powdered activated carbon sorption, filtration, and disinfection by free chlorine. Lime softening effectively removed most nanoparticles added. Source and drinking waters from three large …

Synthesis Of Different Sizes & Functions Nanoparticles, Jiaming Geng

Masters Theses

"Nanogels, whose size range from 1 to 100nm, have been interested in many research areas: cosmetics, pharmaceuticals, catalysts, photochemistry, and in optical switches or sensors. In Petroleum Engineering area, nanogels can be used as conformance control agent and emulsion stabilizer. And after grafting functional groups or hybrid, nanogels can be used as tracer for the visual modeling.

Though nanoparticles have been studied for more than 20 years, few of them are about nanogels. In the thesis, stirring rate, surfactant type and concentration were found have a large impact on the synthesis of nanogels. And cationic nanogels have salt and acid …

Cappack Devices For Enhanced Qnmr Measurements In 1H Nmr Spectroscopy, Lingyu Chi

Masters Theses

"Quantitative NMR analyses can be improved by adding well-defined external references for measuring sample properties on absolute scales. Special Capillary-tube Package (CapPack) devices were invented that provide in situ information (e.g., temperature, pH, pressure, integration, chemical shift, lock, etc.) about a sample with spectral imprimaturs. A new microscale glass-sealing technique produced CapPack devices that can survive high temperatures and pressures in harsh environments. Two CapPack devices are discussed: (1) Gradient CapPack-- a device for examining the irradiation bandwidth of solvent-suppression pulse sequences; (2) T₁ CapPack - a device for examining the T₁ robustness of solvent-suppression pulse sequences. A …

In Vitro Study Of Wound-Healing Capabilities Of Bioactive Glass Fibers Under Various Culture Conditions, Sisi Chen

Masters Theses

"Bioactive borate glass has been recognized to have both hard and soft tissue repair and regeneration capabilities through stimulating both osteogenesis and angiogenesis. However, the underlying physiological and cellular mechanism behind this function remains unclear. In this study, in vitro dynamic flow modules were designed to mimic the micro-environment near the vascular depletion and hyperplasia area in wound-healing regions, and were used to investigate the biocompatibility and functionality of borate glass nano-/micro-fibers. Glass-cell interactions were investigated either by dosing fibers to the upstream of or co-cultured with cells, and two types of borate glasses (with or without CuO/ZnO doped were …

Gold-Magnetite Nanoparticle-Biomolecule Conjugates: Synthesis, Properties And Toxicity Studies, Akshay Pariti

Masters Theses

"This thesis study focuses on synthesizing and characterizing gold-magnetite optically active magnetic nanoparticle and its conjugation with biomolecules for biomedical applications, especially magnetic fluid hyperthermia treatment for cancerous tissue. Gold nanoparticles have already displayed their potential in the biomedical field. They exhibit excellent optical properties and possess strong surface chemistry which renders them suitable for various biomolecule attachments. Studies have showed gold nanoparticles to be a perfect biocompatible vector. However, clinical trials for gold mediated drug delivery and treatment studied in rat models identified some problems. Of these problems, the low retention time in bloodstream and inability to maneuver externally …

Part I: Increased Leaching Of Arsenic, Selenium, Molybdenum, And Vanadium From High Calcium Coal Ash Containing Trona Reaction Products. Part Ii: Using Agricultural Byproduct Rice Hull As Biosorbent To Remove And Recover Metal Ions In Water, Yongbo Dan

Masters Theses

"Part I. The trona is being injected to control SO_x emission from coal-fired power plants. The results showed that trona ash leached significantly more As, Se, Mo, and V than the control fly ash did, especially under the natural pH condition. In addition, trona ash had a significantly greater soluble fraction than the control ash. Further investigation indicated that greater amounts of the studied anionic elements in the trona ash were associated with the soluble, trona reaction products. Moreover, the insoluble fraction of the trona ash lost its capability to adsorb these elements under the natural pH condition. The …

Comparative Evaluation Of N-Acetylcysteine And N-Acetylcysteine Amide In Acetaminophen-Induced Oxidative Stress, Ahdab Naeem Khayyat

Masters Theses

"Acetaminophen (APAP) is the most widely used pharmaceutical analgesic-antipyretic agent in the world, but its toxicity is a common cause of drug-induced hepatotoxicity. With APAP toxicity, cellular glutathione (GSH) is depleted. This results in the availability of N-acetyl-p-benzoquinone imine (NAPQI), is a toxic metabolite of APAP that binds to cellular macromolecules, which leads to cell necrosis. N-acetyl cysteine (NAC), a GSH precursor, is the only approved antidote for an acetaminophen overdose. It is a negatively charged molecule that diminishes its penetration into the cells, thereby requiring fairly high doses that increase the severity of side effects. In addition, oral and …

Role Of Nicotine In Oxidative Stress, Rakesh Kacham

Masters Theses

"Nicotine, a major alkaloid, is present in tobacco products as well as in smaller amounts in potatoes, tomatoes, and eggplants. Although it is the addictive compound in cigarettes, nicotine is believed to play a protective role in neurodegenerative disorders such as Parkinson's disease. Researchers have found that the short-term administration of nicotine may help improve the memory process by reducing oxidative stress in the brain. Our studies have shown that, by blocking Fenton's reaction, nicotine is able to inhibit free radical generation, so this research has focused on the antioxidant properties of nicotine. The cell lines of the alveoli, blood …

Relaxation Imaging To Characterize Lightweight Polymer-Crosslinked Aerogels, Emmalou T. Satterfield

Masters Theses

"Silica aerogels are three-dimensional assemblies of silica nanoparticles with extremely low densities. In some instances, the internal void volume is more than 90% of the total volume. The highly porous structure of the aerogels leads to attractive properties for thermal and noise insulation, due to very low thermal conductivity and very high acoustic impedance. The strength of silica aerogels has been substantially improved by casting a thin conformal polymer coating over the entire internal porous surfaces of the nanostructure. The coating reinforces the interparticle connections without significantly compromising the internal void space. To analyze and compare the properties of several …

Comparing The Chelating Abilities Of N-Acetylcysteine And N-Acetylcysteine Amide In Vitro For Lead Poisoning Treatment, Weiqing Chen

Masters Theses

"Lead poisoning is a perennial and serious health problem around the world. The daily widespread use of lead has dramatically increased the degree and longevity of its exposure to humans, exacerbating the task of lead poisoning treatment. Lead exerts adverse effects on cardiovascular, central nervous, renal, gastrointestinal, and reproductive systems. The common treatment for lead poisoning is chelation therapy. Chelators were proposed to treat lead poisoning a very long time ago. However, chelators have severe side effects that could cause more problems, in addition to lead poisoning. Therefore, another group of drugs has been suggested --- antioxidants. This type of …

Water Analysis For Emerging Environmental Contaminants, Xiaoliang Cheng

Masters Theses

"The presence of emerging environmental contaminants in water bodies used either as drinking water or for recreational purpose has received considerable attention in the recent years. The emerging environmental contaminants can be defined as a wide range of chemicals that have been determined in the environment which may present serious health risks for humans. The occurrence of these contaminants indicate that both household and industrial chemicals have been introduced to water resources, a wide variety of chemicals, such as disinfection byproducts, pharmaceutical and personal care products and so on, have been detected at cetiain levels in either water bodies or …

Obscurant Oil Characterization Produced Through Vaporization By Exhaust Gas Of Mini-Jet Turbine Engine, Hossein Daniel Bahaghighat

Masters Theses

"Obscurants have been used for centuries to conceal and protect military assets from direct enemy attack, or as a signal between units. Obscurants still play a significant role in protecting soldiers on the battlefield. This research was geared towards development of highly efficient man portable obscurant generation system to demonstrate its use with biogenic oils as the obscurants. The research reported in the thesis was directed evaluating the performance of a mini-jet based generator in the laboratory and field with two different obscurant oils, Fog Oil (FO) the oil used by the US Army at present and potential replacement oil …

Polymer Reinforced Aerogels And Composites A. Polyimide Crosslinked Aerogels B. Silica-Polymethylmethacrylate Composites, Vishal U. Patil

Masters Theses

"Crosslinking of aerogels is a promising approach to combine the advantages of inorganic and polymeric materials. In the present study, two types of polyimide-silica hybrid aerogels, APTES-BTDA-MDA (mol ratio: 2:2:1) and APTES-BTDA-MDA (mol ratio: 2:3:2), were synthesized using a sol-gel process followed by heating in order to imidize the polyamic acid that is formed quickly and is covalently bonded to silica. The hybrid aerogels were made using 3-aminopropyltriethoxysilane (APTES) endcapped polyamic acids and tetramethoxysilane (TMOS) as precursors. Polyimide crosslinked aerogels were characterized by TGA, SEM, FT-IR, BET, solid state NMR and gas pycnometry. These hybrid aerogels exhibit high thermal stability …

A Rapid Method For Determination Of Alpha Hydroxy Acids In Seawater And Biological Fluids At Trace Levels, Ryan Lee Schwiderski

Masters Theses

"Alpha hydroxy acids (AHAs) - carboxylic acids with a hydroxyl substitution on the alpha carbon are an important class of molecules. Hydroxy Methyl Thiobutanoic Acid (HMTBA) is an α-hydroxy analog of essential amino acid methionine; it finds extensive use as a feed supplement for avian and bovine species. Efficacy of alpha hydroxy acid uptake is important for nutritional studies and such studies rely on accurate and precise methods for determination of these chemicals in biological samples. Several methods for AHAs determination have been reported, however, the methods are tedious, requiring multiple sample preparation steps. Experiments reported in this thesis were …

Physical Analysis Of Human Hair, Lea Marie Dankers

Masters Theses

"Physical analysis of human hair has been performed to determine the effects of chemical treatments on hair samples. Five samples including an untreated sample were analyzed using various methods. The methods included differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FTIR), and carbon-13 cross polarization/magic-angle spinning nuclear magnetic resonance (¹³C CP/MAS NMR)"--Abstract, page iii.

Glass Transition Behavior Of Thin Poly(Methyl Methacrylate) Films On Silica, Moses T. Kabomo

Masters Theses

"Modulated Differential Scanning Calorimetry (MDSC) was used to study the glass transition behavior of poly(methyl methacrylate) (PMMA) adsorbed onto silica substrates from toluene. Untreated fumed amorphous silica and silica treated with hexamethyldisilazane were used for the adsorption to probe the effect of polymer- substrate interactions. To test the effect of molecular weight on the T_g of adsorbed polymers, low polydispersity PMMA samples of varying molecular weights were used. The results revealed a broadening of the glass transition towards high temperatures. The observed increase in the glass transition breadth varied with adsorbed amount and the type of silica used for …

Characterization Of Petroleum Fog Oil And Vegetable Oil Smokes, Andrew Oliver Larouche

Masters Theses

"Deception and concealment to gain tactical advantage in the battlefield has been an integral part of warfare. Smoke has been a common tool used for signaling, concealment of troop movement and weapon deployment. U.S. Armed Forces have made use of smokes in an organized manner since the 1st world war. Since then various materials such as white phosphorus, zinc chloride, diesel fuel and petroleum oil aerosols have been used to obscure military targets. For the past thirty years fog oil (FO) a medium distillate has been extensively used by the U.S. Armed Forces for generation of obscurant smokes (OS). During …

Molecular Mobility In A Model Polymer Composite, Joan Ethel Gambogi

Masters Theses

"The adsorption of aminoalkysilane coupling agents onto silica surfaces and the interaction of these functional silanes with a bismaleimide and an epoxy resin has been studied using solid-state NMR techniques. ¹³C CP-MAS was used to confirm the bonding between the silence and bismaleimide (BMI) resin and elucidate the nature of the crosslinking reaction of BMI. Deuterated coupling agents were synthesized and adsorbed on silica surfaces. The motional dynamics were probed using deuterium solid-echo NMR. It was determined that the motion of the alky portion of the coupling agents was consistent with gauche migrations (gtt ↔ tig) and pair gauche …

Thermal, Mechanical And Interfacial Characterization Of A Fiberglass Reinforced Plastic Composite, Theodore J. Williams

Masters Theses

The effects of a glass fiber reinforcer on the properties of poly(methyl methacrylate) were evaluated. A silane coupling agent (M8550 Petrarch Systems, Inc.) was employed to promote adhesion between the materials. FTIR analysis, ESCA/Auger and SEM techniques were used to characterize the silane coating.

The mechanical properties, such as bending strength, improved with an increase in the volume percent of fiber. The addition of the M8550 silane directly into the monomer solution showed the most improvement, 23 percent increase, when compared to the uncoated glass fiber. The glass transition temperature as measured by DSC and the heat distortion temperature (HDT) …

The Synthesis And Characterization Of Polycarbonates Based On 1,1'-Dihydroxyethyl-2,2'-Biimidazole, Judith J. Garces

Masters Theses

"The synthesis of polycarbonates formed by the reaction of 1,1'-dihydroxyethyl-2,2'-biimidazole and diphenyl or diethyl carbonates was investigated and the products formed were characterized. The molecular weights of the polymers were dependent on catalyst, ratio of starting materials, nature of carbonate (aromatic or aliphatic) and method of polymerization. Isolated polymers exhibit a linear structure. They have no well-defined melting points (melting pt. range of 280- 330⁰C) indicating low degree of crystallization, and undergo less than 9% decomposition below 200⁰C"--Abstract, page ii.

A Study Of The Electroless Plating Of Sn Onto A Die-Cast Aluminum Alloy, Ann-Tinn Shen

Masters Theses

"A tin layer was immersion plated onto a zinc-silicon containing aluminum alloy by using a potassium stannate solution. Conventional aluminum pretreatment was used before immersion plating.

Effects of immersion time with immersion tin thickness and Al-Sn adhesion were studied. Conditions of subsequent Sn-Pb electroplating on Sn plated aluminum samples were investigated.

SEM (scanning electron microscope) and x-ray energy dispersion studies were extensively used on samples of each stage"--Abstract, page ii.

The Synthesis And Characterization Of Several Copper (Ii) Complexes Of Quinuclidinone-Containing Ligands. Possible Models For Type I Copper Blue Proteins., Victor Thomas Wilcox

Masters Theses

Several copper (II) complexes with bidentate quinuclidinone containing ligands have been synthesized and characterized. These complexes appear to be possible models for the type I copper (II) in the copper "blue" proteins. The spectral and magnetic properties indicate that the complexes have a pseudo tetrahedral microsymrnetry about the central metal ion. The complexes contain chromophores of the following forms: CuN₄, CuN₂O₂, and CuN₂x₂, where X is either Cl or Br. While the spectra of these complexes lack the intense 17,000 cm^-1 band typical of copper "blue" proteins, the optical …

Part I. Thermodynamic Acidities Of Substituted Phenylacetylenes. Part Ii. Mercury Accumulation In Trout Of Southern Missouri, Eric T. Lloyd

Masters Theses

"PART I: THERMODYNAMIC ACIDITIES OF SUBSTITUTED PHENYLACETYLENES The thermodynamic acidities (pKa) of phenylacetylene and several para substituted phenylacetylenes in methanol were determined at 25ºC. These acidity constants were determined using a quenching technique which involves converting the phenylacetylenic anion, present at equilibrium as sodium phenylacetylide, to the tritium labelled carbon acid. By liquid scintillation counting techniques, the concentration of the anion was determined and the pKa of the phenylacetylene compound calculated. The resulting pKa's are: p-nitrophenylacetylene, 17.98, p-bromophenylacetylene, 18.10, p-fluorophenylacetylene, 18.14, phenylacetylene, 18.50, and p-methylphenylacetylene, 18.60. The effect of a substituent in the para position on the relative acidities is …

A Study On Two Iodine Containing Peptides Isolated From Porcine Thyroglobulin, Frederick E. Bishop Jr.

Masters Theses

"Two iodopeptides were isolated from thyroglobulin that had been digested with trypsin by paper electrophoresis and paper chromatography. The amino acid analysis demonstrated that the amino acid compositions were similar. The N-terminal amino acid of both iodopeptides was shown to be leucine. The amino acid sequence of one of the iodopeptides was determined by the Edman degradation method and digestion with the enzyme Carboxypeptidase A. The sequence was shown to be: NH₂-Leu-Asn-Ala-Ser-Glu-MIT-Gly-Thr-Ser-Gly-COOH. Other workers have shown that synthetic tyrosyl peptides with the sequence Glu-Tyr are iodinated by the thyroid peroxidase enzyme with a greater specificity than other tyrosyl peptides. This …

Metal Salt Catalyzed Carbenoids The Catalysts In Trialkyl Phosphite Copper (I) Complex Catalyzed Decomposition Of Diazo Compounds, Nguyen Van Thinh

Masters Theses

"Partial rate data, asymmetric induction studies, interrupted experiments and additives studies indicate that copper(I) salt-phosphite complexes are destroyed during the course of reactions with dimethyl diazomalonate (1) and ethyl diazoacetate (2). All evidence is consistent with the copper(I) being oxidized to copper(II) and copper(0) being oxidized by impurities in the olefin which most probably are hydroperoxides.

Several new copper(I) salt-phosphite complexes were prepared and examined but none proved as effective for decomposing (1) as copper(II) bis acetylacetonate.

The utility of the copper (I) chloride-trimethyl phosphite complex for decomposing (1) is a function of the means of preparation. The three general …

A Study Of The Ability Of Surface Active Materials To Increase The Evaporation Rates Of Small, Freely Falling Water Drops, David Alan Sierawski

Masters Theses

"The evaporation rate at 30°C of water droplets partially covered by surface active materials (SAM) were determined. While two of the SAM were studied at a single dew point depression (ΔT_DP), seven others were examined over a range of ΔT_DP values. It was found, by comparison with pure water drops under identical conditions, that SAM increases the evaporation rate as compared to the rate of an uncontaminated drop. The lack of effect of the hydrophobic chain length and the possible effect of the hydrophilic group on this phenomenon are discussed. The explanation proposed is that at 30°C …