Chemistry Commons^™

Unleaded Drinking Water: Equilibrium Potential Measurements For Monochloramine Disinfectant, Brandi Clark

Opportunities for Undergraduate Research Experience Program (OURE)

The strength of monochloramine, NH₂CI, as an oxidizing agent can be linked to its effect on Pb levels in drinking water. In this study, the equilibrium potential was measured as a function of pH from pH 8 to 12 and compared to a theoretical plot of formal potentials derived from the Nemst equation. The measured equilibrium potential was consistently about 300 mV more negative than the calculated potential - NH₂CI is a weaker oxidizing agent than predicted. When the measured potentials are plotted on a Pourbaix diagram, it is found that NH₂CI can oxidize …

Polymer Gels: Mimickin G Biological Environments, Joshua Carey

Opportunities for Undergraduate Research Experience Program (OURE)

A comparison of the hydrolysis of pyruvic acid in polymer gels and in aqueous environment will be studied using NMR techniques. Relaxation time and diffusion rates will be determined and compared to show the mimicking capability of the polymer gels to that of biological environments. This will allow for a means in which chemical reactions can be performed in a medium that more closely resembles the rate that the reaction would occur in biological systems.

Effects Of Monochloramine And Free Chlorine On Copper Dissolution In Drinking Water, Ryan C. Abington

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The effects of the disinfectant's free chlorine and monochloramine have been studied on thin copper films using the electrochemical quartz crystal microbalance, scanning electron microscopy and x-ray diffraction. It has been found that after twenty-four hours of immersion, the hypochlorite and the monochloramine both convert some of the copper into cuprous oxide. However, after immersion in monochloramine, tiny pinholes in the copper develop on the electrode and the gold substrate is visible underneath. This leads to suggest that while free chlorine may oxidize copper, monochloramine will oxidize copper and can cause pitting in the metal.

Photosensitization Of Photoconductive And Photorefractive Composites Through The Inclusion Of Semiconductor Nanocrystals, Tyler Martin Fears

Opportunities for Undergraduate Research Experience Program (OURE)

A novel synthesis of NiS nanocrystals included in photorefractive polymeric composites is described. The nanocrystals were characterized using visible-absorption spectroscopy, energy dispersive X-ray spectroscopy, and transmission electron microscopy. We further demonstrate the ability to enhance aspects of the composites' photorefractive performance by performing ligand exchange on the nanocrystals prior to their incorporation into the polymer composite. It was originally believed that this modification of the nanocrystals' surface characteristics would result in an enhanced charge-transfer process between the nanocrystal and the charge transporting matrix. However, when the photo conductivities were determined and used in calculating the quantum efficiencies associated with the …

Synthesis And Characterization Of Mercury Vapor Coordination Species Using 1,3-Benzenedioethanethiolate (Bdet), Elizabeth Zuchek, Harvest L. Collier

Opportunities for Undergraduate Research Experience Program (OURE)

Mercury is a major pollutant in the air today. Some possible chelators that have been used are British anti-Lewisite (BAL) 2,3-dimercaptopropanol, dimercaptosuccinic acid (DMSA). diinercaptopropanesulfonic acid (DMPS). and 1,3-benzenediamidoethanethiolate (BDE'I1. All contain two thiol groups, which 'capture' the heavy mercury element. Due to their structure, they all differ in how well they bind to the mercury atom. BDET is the most recent and efficient chelate used. Statistics show that coal-fired power plants are the nation's largest mercury polluter. Steps have been taken to lower the emission of this toxic metal by the Clean Air Act. However, recently The Bush Administration's …

The Synthesis And Characterization Of Poly (1,1'-Divinyl-2,2’-Biimidazole), Timothy S. Evenson

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The monomer 1,1 ,-divinyl-2,2’-biimidazole was prepared using a previously published procedure (1). The new divinyl biimidazole polymer was then synthesized from this monomer. The polymer was characterized by infrared and ultraviolet-visible spectroscopy. Nuclear magnetic resonance confirms the structure of the polymer. Also, gel permeation chromatography was used to determine molecular weight, while differential scanning calorimetry was used to determine the glass transition temperature and crystalline melting point of the polymer.

Macrocyclic Antibiotics As A New Class Of Chiral Selectors For Liquid Chromatography, Christine Bagwill

Opportunities for Undergraduate Research Experience Program (OURE)

In the field of chromatographic separations, the need for new chiral stationary phases is always in demand. Many stationary phases already exist, some of the more popular being cyclodextrin or protein based phases. During this research, a new class of chiral selectors were discovered and evaluated for chiral recognition. Vancomycin, thiostrepton, and rifamycin B all belong to the macrocyclic antibiotic family. Not only can this new class of chiral selectors be used to resolve compounds that cannot be separated on any other column, but it is also more stable and has much greater capacity than protein based columns.

Modified Recycled Glass As An Additive In Coatings Applications, Garth D. Brown

Opportunities for Undergraduate Research Experience Program (OURE)

The feasibility of using chemically modified, finely pulverized recycled glass as an additive in coatings was investigated. The ground glass was added as partial replacement for the conventional pigment titanium dioxide (TiO₂). The loss of TiO₂ pigment was compensated with an optical brightening agent (OB agents). OB agents can help contribute to a coating’s hiding capacity by absorbing light in the UV range, releasing light of a lower energy in the visible spectrum. Glass supplemented coatings were formulated and common paint tests were performed. The glass changed the optical and physical properties of the coating formulations. The …

Synthesis Evaluation Of New High Performance Polymer Systems Involving Tetrachlorohydroquinone, Jason A. Giles

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New high performance transparent polymers are in demand in the aerospace and automotive industries to replace current glass and composite systems. Tetrachlorohydroquinone (TCHQ) was used as the base monomer for various copolymer formulations. Different acid chloride monomers lead to polyester formation with TCHQ. Polycarbonates were formed with triphosgene and diethyl carbonate. This base monomer added rigidity, transparency, and high temperature resistance, however, resulting polymers were brittle and difficult to process. Polymers were characterized by IR and DSC.

Development Of A Recycled Glass Corrosion Inhibitor For Surface Coatings And Concrete Applications, Theresa Pierce

Opportunities for Undergraduate Research Experience Program (OURE)

This research was performed to study the possibility of attaching a metal corrosion inhibitor to recycled glass powder. Such a material would be useful as a corrosion inhibitor component for metal substrate coatings. The major experiments performed were first to produce a metal corrosion inhibitor (Irgacor 153)/silane coupling agent (3-(chloropropyl)trimethoxysilane) adduct and secondly to attach this corrosion inhibitor/silane adduct onto the surface of glass. To test feasibility, qualitative corrosion tests were performed using steel wool as the corroding metal and a number of product samples.

The Electrochemical Characterization Of A Platinum Cyclooctadiene Complex As A Guest Molecule In The Presence Of Ss-Cyclodextrin, Timothy S. Evenson

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The equilibrium constants for the complexation of the dichloroplatinum- cycloocta-1,5-diene complex with p-cyclodextrin in N,N-dimethyl- formamide was determined using electrochemical cyclic voltammetry. The constants for both the oxidized and reduced forms of the platinum compound were determined. Model redox experiments were conducted with ferrocene and 1,1 ’-dimethylferrocene before the platinum compound was studied in order to establish parameters for the experimental method. Also determined was the ratio of the diffusion constants of the guest molecule with and without being complexed with cyclodextrin. In addition to the platinum complex being electrochemically characterized as a guest of cyclodextrin, circular dichroism studies were …

Hypochlorite Oxidation Of Nitrilotriacetic Acid, Audrey P. Linville

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The chemical degradation of nitrilotriacetic acid (NTA) by sodium hypochlorite is examined. Preliminary work indicates that NTA undergoes decarboxylation. In the second phase of this investigation (S92), the work was mainly concerned with the products from the reaction of NTA with hypochlorite. The product of decarboxylation has been found to be iminodiacetic acid. The decrease in concentration of hypochlorite per unit time was studied over a pH range of 7-14 and in the presence of lead, calcium, zinc, and copper ions.

The Synthesis And Characterization Of Metal Binding Polymers Containing 2,2'-Biimidazole, R. A. Proctor

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Epoxides are known to form ring-opened polymer products that have demonstrated improved material strength, high heat stability, and chemical resistance as adhesives, coatings, and molding materials. It has been suggested that imidazoles can be used in the catalysis of this polymerization, and that the pyridyl nitrogen of the imidazole ring participates in epoxy ring-opening and is then incorporated in the polymeric structure. This study was conducted to test this theory of the role of pyridyl nitrogen in the reaction of 1,1'-dihydroxyethyl-2,2'- biimidazole (HEB) and metal-HEB complexes with the diglycidyl ether of bisphenol A (DGEBA). Of particular interest in this study …

Synthesis And Characterization Of An 18-Membered Macrocyclic Ligand Containing 2,2-Biimidazole For Selective Binding Of Transition Metal Ions, Mark Barnett

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A description of the synthetic approach to the preparation of an 18 membered macrocyclic ligand containing 2/2'-biimidazole is presented. A diol derivative of 2,2'-biimidazole is tosylated with p-toluene sulfonyl chloride making it susceptible to bimolecular substitution with a disodium salt of tetratosylated triethylenetetraamine. The final desired product is an 18N6 macrocycle, 4,7-(l,l'-(2,2'-biimidazolo))-l,4,7,10,13,16-hexaazacyclooctadecane, potentially capable of binding transition metal ions in various combinations with three chelating sites. Initial characterization includes NMR and IR spectroscopic analysis.

Analysis Of Two Circuits For Detecting Superconducting Transition Temperatures, Terry Bowness

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When measuring the transition temperature of large numbers of high T_c superconducting samples it is desirable to have available equipment that is both easy to operate and reliable. In addition should anything malfunction, the device should be relatively simple to repair. One method of measurement involves placing a sample in the magnetic field of an inductor, the inductor being an active member of some type of oscillating circuit. There are many standard oscillator designs which can be used for this type of application. In this report two such circuits, the tunnel diode and Hartley oscillators, will be examined and …

Model Calculational Approach To The Conformation Of Adsorbed Polypeptide Fragments, Timothy J. Mckeon

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The focus of the paper is to examine possible conformational changes of peptides when placed in the presence of a poly-synthetic material. A major concern in the pharmaceutical industry is the loss of potency of polypeptide drug products during processing, packaging and storage. An example of this is polymer syringes being used in place of glass ones. The effect is that some protien-derived products experience structural changes due to contact with the polymer. This is otherwise known as surface denaturation. In order to understand the energetics of interfacial polypeptide systems, a calculational approach was used via the program Alchemy. The …

Enantiomeric Separation By Cloud Point Precipitation Of Cyclodextrins, Deanna L. Schmid

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Certain cyclodextrins exhibit a diminishing solubility in water when heated. This phenomena of cloud point precipitation in conjunction with cyclodextrin's ability to form an inclusion complex with many compounds, can be used as a method of chemical separation. These cyclodextrins can be removed from the solution after precipitation by a hot filtration technique and the remaining solution analyzed by HPLC. Enantiomeric separations, concentration of compounds and removal of hazardous organic materials are all possible applications of cloud point extraction using cyclodextrins.

Stimulation Of Amorphous Layers In The Co-Si System By Third Element Additions, Denise Brandt

Opportunities for Undergraduate Research Experience Program (OURE)

Multilayer thin films play an important role in our technology today. They can be found in many devices such as magnetic hard disks, microelectronic circuits, and x-ray optical elements. In many of these metal-metal and metal-metalloid multilayers, amorphous layers have been discovered using various techniques such as extended x-ray absorption fine structure (EXAFS) and high resolution transmission electron microscopy (HTEM). These amorphous layers enhance the magnetic and electrical properties of the alloy. They also affect the mechanical and structural properties of the system.

The solid state amorphous reactions (SSAR) occur whether the layers are formed by epitaxy or by sputtering. …

Fourier Transform Infrared (Ftir) Spectroscopy Analysis Of Combustion Aerosol, Gary Jacquin

Opportunities for Undergraduate Research Experience Program (OURE)

In conjunction with my co-op program at McDonnell-Douglas, my current OURE project is the analysis of combustion aerosols using Fourier Transform Infrared (FTIR) Spectroscopy. Aerosol science is a very important field as it is concerned with atmospheric chemistry, atmospheric physics, climate, public health, and environmental issues.

In the Cloud and Aerosol Sciences Laboratory (CASL) at UMR, combustion aerosols are generated by an in-house designed torch or burner. The fuels, JP4 and JP5, are provided by McDonnell-Douglas. Some other commercial fuels are also used. The primary objective of my OURE project was to generate and collect combustion aerosols for chemical analysis. …

The Synthesis And Characterization Of Metal Binding Polymers Containing 2,2'-Biimidazole, Renee Proctor

Opportunities for Undergraduate Research Experience Program (OURE)

Epoxides are known to form ring-opened polymer products that have demonstrated improved material strength, high heat stability, and chemical resistance as adhesives, coatings, and molding materials. It has been suggested that imidazoles can be used in the catalysis of this polymerization, and that the pyridyl nitrogen of the imidazole ring participates in epoxy ring-opening and is then incorporated in the polymeric structure. This study was conducted to test this theory of the role of pyridyl nitrogen in the reaction of 1,1'- dihydroxyethyl-2,2’-biimidazole (HEB) and metal-HEB complexes in reactions with the diglyddyl ether of bisphenol A (DGEBA). Of particular interest in …