Chemistry Commons^™

Educational Technology: Podcasts, Vodcasts, And Blogs In The Science Classroom, Danielle N. Thompson

Masters Theses

Junior-level Chemistry students at De Soto High School, Missouri, were introduced to educational technology in the form of podcasts, vodcasts, and blogs to facilitate learning outside of the traditional four walls of the classroom. Educational technology was utilized to see if content knowledge could be delivered from the teacher to the students as well as from the students to the teacher. Students were surveyed eight weeks after educational technology was introduced in the classroom to see if participation, attitudes, and interests in science were influenced by the use of educational technology in addition to traditional pedagogical methods.

Ruthenium Polypyridyl Complexes That Utilize Azo-Dyes To Enhance Absorption Of Visible Photons, Akram Hazeen

Masters Theses

Research in the field of dye sensitized solar cells has been growing rapidly. The challenge in this field is to prepare molecules that absorb in the visible region. An azo dye ligand based on l,0-phenanthroline, "phen-azo-phenol", was prepared and found to absorb at 380 nm in MeOH. UV-Vis spectra of this ligand were recorded in different solvents and in the presence of added acid or base and it appeared that the spectra were shifted to longer wavelength (around 500 nm) in the presence of base and/or basic solvents. This was attributed to deprotonation of the phenol portion of the ligand. …

Utilization Of Phosphorus Ylides Towards The Synthesis Of Extended Cinnamaldehydes And Stellettins, John M. Saathoff

Masters Theses

Phosphorus ylides have been utilized in three synthetic approaches; two involving the synthesis of photochromic cinnamaldehyde semicarbazones and a final scheme towards the synthesis of the isomalabaricane natural products. The targeted cinnamaldehyde semicarbazones varied both in the length of the conjugated system as well as the position and type of phenyl ring substituents, because these variations could impact their degree of photochromicity. The three step synthesis of the extended cinnamaldehyde semicarbazones involved a Wittig condensation, hydrolysis of acetal protecting group, and formation of imine and was completed in respectable cumulative yields; 42.4% yield for semicarbazones with n = 1 double …

Electrochemical Characterization Of Thin-Film Perovskite-Type La1-Xsrxmno3 Electrodes Obtained By Pulsed Laser Deposition (Pld), Keerthi Chandra

Masters Theses

The implementation of fuel cells into commercial usage is prenominally dependent on the activity of cathode at which oxygen reduction reaction (ORR) takes place. Fuel cells currently use noble metals like platinum, palladium etc as cathode for the reduction reaction. These metals showed poor performance during changes in red ox environment. Perovskite oxides which were proven to be efficient as cathodes in solid oxide fuel cells operating at high temperature was studied to understand its ability to carry out ORR in alkaline fuel cells operating at room temperature.

La_1-XSr_xMnO₃ (LSMO), thin film perovskite oxide, a …

Simultaneous Electrochemical Determination Of Tryptamine And Barbituric Acid, Luxshani Thangarajah

Masters Theses

The ability to analyze mixtures of two or more red-ox active components "on-the-spot" without the need to carry the sample into a laboratory is typically limited by the fact that various components need to be separated before they can be quantified. Reducing the two-step protocol (separation and detection) to a single one (detection) would markedly shorten the analysis time and simplify the analysis.

Exploring Phenyl Embrace Interactions In Trityloxy And Tritylamino Aromatic Compounds, Premnath Basa

Masters Theses

The area of supramolecular chemistry seeks to understand the organization of molecular structures and the interactions that hold such assemblies together by non-covalent interactions such as electrostatic, hydrogen bonding, π-π stacking interactions, and hydrophobic or solvatophobic effects. One such example that comes under supramolecular chemistry is the phenyl embrace interaction. These interactions occur due to the cooperative participation of at least three or more neighboring phenyl groups arranged as an interlocking propeller configuration to give complementary edge-to-face or offset face-to-face interactions. In order to understand the effect of functional groups on the tendencies of organic compounds to form phenyl embrace …

The Affect Of Surface Hydrophobicity On Wind Erosion Probed By Atomic Force Microscopy, Bradley Eric Frost

Masters Theses

Several field and laboratory studies have shown indirectly the effects of atmospheric humidity on soil particle adhesion through reduced resistance to movement by wind as the humidity decreases. Similar studies have also shown that increased hydrophobicity has the same effect on susceptibility of soil particles to movement by wind as reduced humidity. Theoretical models of idealized soil particle cohesion by water menisci in equilibrium with the atmospheric humidity have been used to explain these results. However the interpretation of these phenomenological results has never been tested by direct measurement of soil inter-particle cohesion as a function of humidity and hydrophobicity. …

Catalytic Activity Of Titania And Titania-Containing Nanomaterials: And, Spatial Distribution Of Silica Surface Groups Using A Tethered Amine Catalyst, Ramkumar Samala

Masters Theses

Titania and titania-containing nanomaterials are semiconductor photocatalysts and are widely used to degrade (i.e. oxidize) organic matter. The adsorption and catalytic properties of highly dispersed titania prepared using sulfate and pyrogenic methods, and fumed containing mixed oxides, were studied using catalytic decomposition of methylene blue primarily by kinetic methods. Commercial ultrafine titania (PC-100, PC-105 and PC-500), fumed Ti 02, and the mixed oxide of 80% Silica/20% Titania (ST20) were studied. Catalytic activity as measured by methylene blue decomposition kinetics was highest per gram for non-treated ultrafine titania PC- 500 which has the highest SsET and smallest particle size. However this …

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 …

Structural And Photochemical Behavior Of Phenyl And Dihydrophenyl Sulfonamidecinnamic Acids, Sergey Zinovchik

Masters Theses

Controlling chemical processes and directing product formation has been a long sought-after goal of synthetic chemists. Most synthesis techniques focus on reactions performed in solution. Such traditional approaches have several disadvantages including unwanted side products, disrupting chemical processes and low reaction yields. A proposed approach to circumvent these drawbacks focuses on performing reactions in the solid state. This method promises better control and higher reaction yields due to the controlled environment of the reaction components. Because molecules in the solid state are effectively fixed, reactions can be performed with a high degree of selectivity, reducing side products and eliminating unwanted …

Method Developments To Analyze Caffeine And Acesulfame-K Concentrations In Natural Waters In And Around Charleston, Il, Usa, Laleen Bodhipaksha

Masters Theses

Analytical methods using batch solid phase extraction were developed for two chemical markers, caffeine and acesulfame-K, to assess anthropogenic water contamination of natural water bodies in and around Charleston, Illinois.

Measurements were conducted on 12 different extracted samples using reverse phase HPLC. Two creek samples showed the presence of acesulfame-K (0.45 ± 0.10 and 0.25 ± 0.06 ppb) and two creek samples showed the presence of caffeine (3 .1 ± 1.2 and 1.6 ± 0.6 ppb ). Effluent from the Charleston waste water treatment plant showed an acesulfame-K concentration of 0.67 ± 0.15 ppb.

These results indicate measurement of both …

Synthesis Of Molecular Containers Based On Modifications Of Resorcin(4)Arene And Calix(4)Arene, Anupama Makineni

Masters Theses

This research work was mainly focused on the synthesis of molecular containers based on modifications ofresorcin[4]arene and calix[4]arene.

The modifications of resorcin[ 4 ]arene include the attempts to attach a phthalimide featured linker onto the phenol hydroxyl groups of resorcin[4]arene. A few halogen leaving groups were used, including fluorine, chlorine, and bromine. The substitution with tetraflorophthalimide resulted in a mixture of regio-isomeric products, whereas for 4,5-dichloro- and 4,5-dibromophthalimides, no desired substitution product was formed. It was, however, discovered that both 4,5-dichloro- and 4,5-dibromophthalimides forms monoclinic crystals. The second modification of resorcin[4]arene focused on functionalizations of both upper and lower rims …

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 …

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 …

Degradation Of Organic Matter In Water In The Presence Of Catalyst And Uv Radiation, Bimali Bandaranayake

Masters Theses

Organic contaminants specially dyes, presents in water is a major environmental problem. Organic compounds can be degraded completely in the presence of photocatalysts and UV radiation. The kinetics of degradation of three dyes was studied using a variety of UV photocatalytic materials. The dyes (methylene blue, malachite green, chrysodoine R) were chosen based on their polarity differences. Catalysts consisting of pure TiO2, mixed oxides of TiO2 containing SiO2, and others containing SiO2 and iron oxide, SiO2/ ZrO2/ CeO2, and CeO2/SiO2 were studied. The TiO2/ SiO2 and SiO2/ZrO2/CeO2 catalysts exhibited the highest degradation rates for methylene blue. The more hydrophobic pure …

Nanoporous High Surface Area Silicas With Chelating Groups For Heavy Metal Ion Adsorption From Aqueous Solution, Kothalawalage Nuwan Kothalawala

Masters Theses

Nanoporous high surface area silicas are an ideal substrate for the design of materials with useful properties via chemical surface modification. The adsorption of heavy metals for contaminated water detoxification is one potential application. In this work we have used three different kinds of silica substrates with varying pore structures; commercially available narrow pore and wide pore silica gels, as well as surfactant templated mesoporous SBA-15 exhibiting a relatively narrow pore size distribution. These silicas have each been subjected to post-synthesis modification with an organosilane consisting of ethylenediamine triacetic acid functionalities for chelation/adsorption of metal ions from aqueous solution. The …

Ditopic Dithiophosphonates And Their Related Rotaxanes, Robert Ray Baum Jr.

Masters Theses

Grafting dithiophosphonate groups onto a naphthalenediimide core yields anionic axles, which in conjunction with the 15DN38C10 crown ether and cationic metallic systems generate neutral bimetallic rotaxanes. The association constant for the rotaxane system was calculated by the single-point method using 1H NMR spectroscopy. Metallic systems reacted with our anionic axles were SnMe3, SnPh3, Cu(PPH3)i, SnMe2, and SnPh2. The structures of several axle-metal complexes and one rotaxane were obtained by X-ray crystallography.

Cloning, Overexpression, Purification And Characterization Of Gcp Ii Homologous Metalloprotein From Caulobacter Crescentus, Dilani Nilushika Gigiriwala Gamage

Masters Theses

A novel zinc metalloprotease gene isolated from Caulobacter crescentus (CCM) was cloned and overexpressed in Escherichia coli. A protease database search using MEROPS predicted this protein is a homolog of Glutamate Carboxypeptidase II (GCP II), a zinc metalloprotease found in humans and many other organisms. GCP II is considered as a suitable target for treating stroke, neurological disorders and a biomarker for prostate cancer. Chromatographic purification of CCM produced pure protein in milligram quantities. Molecular weight detern1ination using MALDI-TOF showed 51,582 Da and the extinction coefficient was found to be 33,007 M"1cm·1. Metal analysis and substrate profiling showed neither sufficient …

Stability Of Heme Proteins: Cytochrome C And Horseradish Peroxidase, Mini Gupta

Masters Theses

A heme protein is a metalloprotein containing the heme prosthetic group. This prosthetic group is responsible for the wide range of biological functions found in heme proteins, from oxygen transport to electron transport. Moreover, heme proteins show a fascinating range of folding architectures, leading to their interest in research on structure-function relationships. The objective of this research in bioinorganic chemistry is to study the structural stability of two heme proteins, iron cytochrome c (Fecyt) and horseradish peroxidase (HRP). Absorbance spectroscopy is used to monitor the structural changes in the protein environment around the heme prosthetic group.

With just a change …

Electrochemical And Spectroscopic Characterization Of A Polypyridyl Ru(Ii) Complex Containing A Fused Alloxazine, Waynie Wilson Olaprath

Masters Theses

Phenanthroline pteridinedione (pptd) is an alloxazine derivative capable of 2e/ 2H+ transfer reactions. Coordination of pptd to a Ru(II) metal center allows for the synthesis of water-soluble metal complexes capable of being reduced by as many as 6 Hatoms making them candidates to be electrochemical mediators. This thesis describes the synthesis and characterization of pptd and [Ru(bpy)2(pptd)](PF6)2(b py = 2,2-bipyridine). The dipyrido[3,2-a: 1' ,2' -c] phenazine (d ppz) and [Ru(bpy)2(d ppz) ](PF6)2 are also synthesized and studied in order to distinguish the properties of the free and coordinated pteridinedione-based pptd ligand from the well-characterized phenazine based ligand.

Detailed cyclic voltammetry, …

Molecular Structures And Pulsed Discharge Emission Studies Of Volatile Organic Compound Derivatives, Ashley Osthoff

Masters Theses

Understanding the structure and reactivity of volatile organic compounds (VOCs), hydrochlorofluorocarbons (HCFCs) and their derivatives is a fundamental concern in the study of atmospheric chemistry. Recently, a series of studies were done aimed at constructing and optimizing a rapid-scan, midinfrared spectrometer in order to study the structure and intermolecular interactions of these compounds. Visible emission spectroscopy was used to optimize the pulsed discharge nozzle that would be used within the infrared spectrometer. The emission spectra of toluene and xylene were used to characterize production of free radical compounds. In addition, control programs were written in the Lab VIEW programming language …

Origin Of Size-Dependent Energy Transfer From Photoexcited Cdse Quantum Dots And Fluorescent Dyes To Gold Nanoparticles, Mariana Kondon

Masters Theses

The photoluminescence quenching of CdSe quantum dots (QD) and fluorescent dyes by hexanethiolate Mono layer Protected Clusters (MPCs) with core diameters of 1.1- 4 .9 nm is described.

The CdSe QD investigated had the following core diameters of 2.0, 2.6, 3.4 and 6.9 nm. The florescent dyes used were: Coumarin 440 (CM440), Fluorescein 548 (F548), Rhodamine 6G (R6G), Pyromethene 597 (PM597) and Lyssamine Dye (LD700). Experimental evidence suggests that the photoluminescence quenching of both CdSe QD and the fluorescent dyes occurs through energy transfer and that the AuMPCs are efficient quenchers in both cases. The larger MPCs are more efficient …

Optical And Electrochemical Molecular And Nanoscale Sensors For The Selective Detection Of Organophosphorus Based Pesticides, Chandrima De

Masters Theses

Organophosphorus based pesticides are highly toxic and represent serious environmental concerns. These compounds tend to easily enter ground water and cause drastic pollution. The toxicity levels of the organophosphorus pesticides however are based on their structures, and hence methods for their selective detection are in high demand. The creation of new materials for sensing and actuation requires careful manipulation of the responsive units required to control analyte selectivity. We have successfully designed and synthesized a molecular sensor based on the family of stilbenes that not only can detect organophosphorus pesticides, but also distinguish between them. Four different pesticides have been …

Characterization Of P62, Hah1 And Their Interaction With The Wilson Disease Protein, Paul Sifuna Oshule

Masters Theses

Wilson disease is an autosomal recessive disorder resulting in the accumulation of copper in the body primarily in the liver and brain. In order to understand the pathogenesis of Wilson disease, our laboratory is studying several different proteins. Wilson disease protein (ATP7B) is a P-type ATPase which acts to remove excess copper from the cells. The p62 subunit of the dynactin complex is a protein whose function is still unknown but it has been proposed to have a copperdependent interaction with ATP7B. HAH1 is a human metallochaperone that binds copper as it comes into the cells from CTR1, a permease. …

Blocked Localized Wavefunction Analysis Of Π And Σ Bonds In The Metal Carbonyl, Kazuhito Nakashima

Masters Theses

The bonding features in group 10 and 11 metal carbonyls Ni(CO), Pd(CO), Pt(CO), [Cu(CO)]+, [Ag(CO)]+, and [Au(CO)]+ have been studied with BLW method. The carbon monoxide is well known as both a π acceptor and a σ donor. The π back bonding and o bonding are synergistic in these metal carbonyl complexes, because the π donation from the metals polarizes the metals and creates a negative force field as an additional driving force on the σ donation from the carbon end of CO vice versa. The synergistic effect in the metal-carbonyl bonds can be described by decomposing the binding energy …

Real-Time Analysis And Investigation Of The Mechanism Of The Palladium On Carbon Catalyzed Isomerization Of Megestrolacetate, Charlene K. Wiglesworth

Masters Theses

Megestrol Acetate is a semi-synthetic steroid hormone of the progestin family and currently used as a drug therapy in many areas including treatments of cancers and AIDS. The final step to form the bulk drug is an isomerization using palladium on carbon with cyclohexene as an activator. This step is sensitive to catalyst quality and is hazardous to sample because of the reactivity of the catalyst. Physical and catalytic properties of the catalyst were evaluated, as were the effects of solid support and different washing strategies. Response of the reaction mixture to catalyst poisons was studied as a function of …

N-(Deoxyadenosine-8-Yl)-4-Aminobiphenyl Adduct Formation In Vitro On Tp53 Exon7 Genome: Quantitation By Lc-Esi-Ms/Ms, Paul René Knoll

Masters Theses

The p53 protein has been documented to be mutated in more than 50% of late stage bladder cancers and tobacco causes 50% of all bladder tumors. The 4- arninobiphenyl (ABP) carcinogen comprises 5 ng per cigarette in the smoke and is a known bladder carcinogen. The research goal in the present study was to compare the reactivity of rat liver S-9 fraction activated 4-arninobiphenyl with the 45-mer sense strand of the TP53 exon7 gene to the respective anti-sense strand. The specific and sensitive technique of LC-tandem mass spectrometry (LC-MS/MS) was used for quantitation. The authentic standard of N-(adenine-8yl-)-4-arninobiphenyl (A-ABP) …

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 …