Chemistry Commons^™

Modeling Corrosion In Oxygen Controlled Lbe Systems With Coupling Of Chemical Kinetics And Hydrodynamics-Phase Two, Samir Moujaes, Yitung Chen

Transmutation Sciences Materials (TRP)

The proposed work will combine chemical kinetics and hydrodynamics in target and test-loop lead-bismuth eutectic (LBE) systems to model system corrosion effects. This approach will result in a predicative tool that can be validated with corrosion test data, used to systematically design tests and interpret the results, and provide guidance for optimization in LBE system designs. The task includes two subtasks. The first subtask is to try to develop the necessary predictive tools to be able to predict the levels of oxygen and corrosion products close to the boundary layer through the use of Computational Fluid Dynamics (CFD) modeling. The …

Oxidation Of Ethylenediaminetetraacetic Acid By N-Bromosuccinimide In Aqueous Alkaline Medium -- A Kinetic Study, S. K. Mavalangi, M. R. Kembhavi, S. T. Nandibewoor

Turkish Journal of Chemistry

The kinetics of oxidation of ethylenediaminetetraacetic acid (EDTA) by N-bromosuccinimide (NBS) in aqueous alkaline media was investigated at 25°C. Analysis of the results showed the reaction is first -- order with respect to [NBS] and apparently less than unit order each with respect to [EDTA] and [alkali]. The influence of the reaction products, ionic strength, temperature effect and dielectric constant of the medium on the rate of reaction was studied. The proposed mechanism is consistent with the observed kinetics. The reaction constants involved in the mechanism were derived. There is a good agreement between the observed and calculated rate constants …

Synthetic Approach To Hexaoxa[6]Peristylanes. A Novel Ddq-Induced Oxidative Rearrangement, Douglas Arthur Otte

Honors Theses

The structural beauty and interesting bonding properties of polycyclic cage compounds have been a source of fascination to many chemists. In this work, progress toward the synthesis of large oxabowl systems, such as hexaoxa[6]peristylane and its derivative dipbenylhexaoxa[6)peristylane, is described. Thus, the adduct obtained from the cycloaddition of maleic anhydride and cyc!ooctatetraene is converted into key dicarbonyl intermediates. Subsequently, the ozonolysis of these intermediates is carried out in order to generate hexaoxa(6)peristylane as well as diphenylhexaoxa[6]peristylane. Molecular modeling studies, performed at the semi-empirical level, are also described.

Oxidation And Adsorption Of Deoxyribonucleic Acid At Highly Ordered Pyrolytic Graphite And Glass Carbon Electrode, Jian-Zhang Zhou, Ling-Ling Wu, Jin Luo, Zhong-Hua Lin

Journal of Electrochemistry

It is shown that calf thymus DNA (CT DNA) can be adsorbed at highly ordered pyrolytic graphite (HOPG) electrode and detected by differential pulse voltammetry (DPV) and electrochemical atomic force microscopy (ECAFM). It is found that controlled potential pre-polarization influences largely the adsorption of dsDNA while it has little influence on ssDNA. It is demonstrated that ECAFM is useful to exploit adsorption of DNA at HOPGE. The pattern of adsorption of DNA at HOPG electrode that fits best with the experimental data is proposed. The results aslo shows that UV/Vis reflection spectroscopy, which has not been used in studying electrochemical …

Oxidation Mechanism Of Hypophosphite, Dong-Bai Sun, Ying Jin, Hong-Ying Yu, De-Jun Yang

Journal of Electrochemistry

There exist two oxidation current peaks on the anodic polarization curve between -0.7 V and 0 V (SCE) in Na-hypophosphite solution. Peak Ⅰ (-0.55 V, SCE) , which represents the oxidation process from H₂PO₂^- to H₂PO₃^-, has been studied previously. Peak Ⅱ, which is located at the potential about -0.4 V (SCE), is investigated emphatically in this paper. The results show that, peak Ⅰ and Ⅱ are corresponding to two successive steps in oxidation process of H₂PO₂^-, i.e. peak Ⅱ corresponds to the oxidation process of …

Oxidation Of Benzoins To Benzils Using Bismuth(Iii) Nitrate-Copper(Ii) Acetate, Ram Mohan, Steven Tymonko, Bryce Nattier

Scholarship

Benzoins are oxidized to benzils in excellent yields by 0.4 equivalents of Bi(NO₃)3.5H₂0 and 4 mol% of Cu(OAc)₂₃)₃.5H₂0 is a stable, inexpensive, commercially available solid. The relatively low cost and low toxicity of bismuth(Ill) nitrate makes this procedure a particularly attractive method for oxidation of benzoins.

The Determination Of The Crystal Structure Of 2-Methyl-2methylacrylyl-Cyclohexanone- (1,5)-Diaxaspiro Mononeopentyl By X-Ray Christallography, Joann Stevenson

McCabe Thesis Collection

Cyclohexanone, the central component of the compound 2-methyl-2-methylacrylylcyclohexanone-( l,5)-diaxaspiro mononeopentyl (see figure on page 2), serves as a solvent for oil in piston type aircraft and in natural and vinyl resins. It is used in the production of crude rubber, waxes, fats, shellac and DDT and other pesticides. Cyclohexanone also is a part of the production of adipic acid, which is used to prepare nylon and is used to prepare cyclohexanone resins via condensation to enhance the adhesive properties of products like floor paints.

Cyclohexanones are among the most accessible hydroaromatic derivatives and serve as the initial materials for the …

The Electrochemical Oxidation Of Organic Selenides And Selenoxides, Michael D. Ryan, Jiyi Yau, Michael Hack

Chemistry Faculty Research and Publications

The electrochemical oxidation of alkyl and aryl selenides was investigated in acetonitrile. The oxidation of diphenyl selenide and di(4‐methylphenyl) selenide led primarily to the formation of their respective selenoxides, which were identified by exhaustive coulometric oxidation and and analysis of the products. The selenoxide itself was not observed in the cyclic voltammetry of the selenide for two reasons: first, the protonation of the selenoxide by the acid formed from the reaction of water with the cation radical and second, the formation of a selenoxide hydrate. The formation of the hydrate with diphenyl selenoxide was verified by isolation of the dimethoxy …

The Oxidation Of Hydrogen Absotbing Alloys And Its Inhibition, Suqin Wang, Baojia Xia, Geping Yin, Pengfei Shi

Journal of Electrochemistry

This paper introduces the method to judge: 1)the possibility of oxidation of themetal hydride electrode in an anode process by cyclic voltammetric curves, 2)the oxidation pattern ofmetal hydride electrode in oxygen atmosphere in various charged states, and 3)the inhibition ofoxidation of hydrogen absorbing alloys by certain surface treatment.

Synthesis, Characterization, And Molecular Structure Of Bis(Tetraphenylcyclopentdienyl)Rhodium(Ii)⊗, James E. Collins, Michael Castellani, Arnold L. Rheingold, Edward J. Miller, William E. Geiger, Anne L. Rieger, Philip H. Rieger

Chemistry Faculty Research

A 5 day diglyme reflux of Rh(acac)3 and K(C5HPh4), followed by treatment with aqueous HPF6, produces orange-yellow [(C5HPh4)2Rh]PF66 in 40 - 50% yield. Reduction of [(C5HPh4)2Rh]PF6 with sodium amalgam in THF yields olive green (C5HPh4)2Rh in 70% yield. (C5HPh4)2Rh crystallizes in the triclinic [Error : unloaded OLE object or mail attachment]space group with unit-cell parameters of a = 8.622 (3) Å, b = 10.778 (4) Å, c = 12.894 (5) Å, a = 65.58 (3)°, b = 72.66 (3)°, g = 83.52 (3)°, and Z = 1. The least squares data refined to RF = 7.63% and …

A Diffuse Reflectance Infrared Fourier Transform Spectroscopic Investigation Of The Oxidation Of Co On Platinum/Tin(Iv) Oxide-Based Catalysts, Julie Christi Stiltner Patrick

Chemistry & Biochemistry Theses & Dissertations

Platinum/tin(IV) oxide-based catalysts have been developed for the oxidation of carbon monoxide at 55 °C and 1 atmosphere pressure. A diffuse reflectance infrared fourier transform spectroscopic (DRIFTS) investigation of this oxidation has been performed. Four catalyst samples have been subjected to a 5% carbon monoxide pretreatment at 125 °C, helium exposure at 55 °C, bottled air (20% oxygen) exposure at 55 °c, and exposure to a 2:1 stoichiometric mixture of carbon monoxide and oxygen at 55 °C. During the course of these exposures, evidence for the development of two different surface carbon monoxide configurations has been found: one that is …

Synthesis, Characterization, And Crystal Structure Of The (Η5-C5ph5)Cr(Co)3 Radical, Ray J. Hoobler, Marc A. Hutton, Mills M. Dillard, Michael Castellani, Arnold L. Rheingold, Anne L. Rieger, Philip H. Rieger, Thomas C. Richards, William E. Geiger

Chemistry Faculty Research

The reaction between Cr(CO)₆ and Na(C₅Ph₅ ) in refluxing diglyme yields [Na(diglyme)_3/2][(C₅Ph₅)Cr(CO)₃], 1. Metathesis of 1 with [Ph₃P=N=PPh₃ ]Cl in CH₂Cl₂ yields [Ph₃P=N=PPh₃][(C₅Ph₅)Cr(CO)₃], 2. Oxidation of 1 by AgBF4 in cold THF under an argon atmosphere produces (C₅Ph₅)Cr(CO)₃, 3. Complexes 2 and 3 form a redox pair connected by a quasireversible one-electron process, E⁰ = -0.69 V vs ferrocene in CH₂Cl₂, …

Oxidation Of N,N-Dimethylformamide And N,N-Dimethylacetamide In A Photoreactor, Su-Jen Syu

Theses

Oxidation of N,N-dimethylformamide(DMF) and N,N-dimethylacetamide(DMA) was investigated in a 30 liter semi-batch reactor. Five reaction processes were studied by using UV alone, O₃ alone, O₂/UV, O₂/O₃/UV and H2 O₂/UV respectively. Mathematical models have been developed to interpret the reaction kinetics. Reaction rate constants and mass transfer coefficients were determined by using Rosenbrock Hillclimb optimization algorithm. The experimental data and the predicted results from the models were compared. The kinetic parameters obtained from the previous semi-batch modes were applied to the continuous stirred tank reactor (CSTR) system. Results of this work show …

Mott G-Ratios In Rbx(Nh3)1-X And Oxidation State Of Rubidium Compounds From Xas, Juana Vivó Acrivos, K. Hathaway, A. Robertson, M. P. Klein, A. Thompson

Faculty Publications, Chemistry

The x-ray absorption spectra (XAS) of Rb metal, Rh,("JH,J, ,, 2H-NbSe2Rb111x and RbBr near the Rb K-edge have been used to ascertain that the oxidation state V of rubidium dissolved in ammonia and intt:rcalated in the layer compound is in the range 0 < V < I. Theobservededge shifts with temperature for semimctals are explainedin terms of the population of band states, and the ratio of the density states near the mobility edge over that calculated for a free electron model, i.e. the Mott ratio g, is ascertained using a semiempirical relation developed for the x-ray absorbance from Is levels to empty states ncar the mobility edge.

Surface Area Of Coal As Influenced By Low Temperature Oxidation Processes, Salvador Leon Arredondo

Dissertations and Theses

The possibility of increasing the amount of readily accessible surface area by enlarging the 5 A pore was examined via pretreating the PSOC-371 coal with gases such as nitrogen, nitrogen-oxygen, and ozone-oxygen and hydrogen peroxide solutions. Surface areas were obtained from nitrogen adsorption at 77 K and carbon dioxide adsorption at either 298 or 195 K for each sample before and after treatment.

The Electrochemical Oxidation Of Substituted Catechols, Michael D. Ryan, Alice Yueh, Wen-Yu Chen

Chemistry Faculty Research and Publications

The oxidation of substituted catechols was studied by cyclic voltammetry, chronoamperometry, rotating ring‐disk electrode, and coulometry. The results showed that the quinones that were formed from the oxidation of substituted catechols reacted with the basic forms of the starting material to yield the dimeric product. These products were generally unstable and rapidly polymerized or underwent some other irreversible reaction to form an electroinactive product. For 3,4‐dihydroxyacetophenone and propriophenone, the intermediate was stable long enough to be observed in cyclic voltammetry. The rate of the coupling reaction was found to correlate well with the Hammett ρ‐σ parameters and indicated that there …

The Vapor Phase Oxidation Of 1, 3-Pentadiene, David E. Sasser

Retrospective Theses and Dissertations

The vapor phase oxidation of 1.3-pentadiene, over heterogeneous catalysts, was investigated with the objective of producing 2,4-pentadienal and 2,4-pentadienoic acid. Copper and cobalt-molybdenum catalysts, both supported and unsupported, were utilized at various reaction temperatures, residence times and feed ratios. The matter of 1,3-pentadiene vaporization and introduction into the reactor system proved to be critical. Low temperature vaporization of the hydrocarbon and dilution with the oxidant, air, was found to be necessary to avoid polymerization of the feed. Alumina-supported catalysts were found to be very active, leading to severe cracking of the hydrocarbon feed and subsequent carbonization of the catalysts. Silica-supported …

The Liquid Phase Oxidation Of 1,3-Pentadiene, Carl B. Reaves

Retrospective Theses and Dissertations

The liquid phase autoxidation of 1,3-pentadiene to 2,4-pentadienoic acid utilizing gaseous oxygen at atmospheric pressure was investigated as a possible route for direct utilization of piperylene obtained during the cracking of naptha to ethylene. Catalyst system consisting of cobalt, manganese, and iron salts promoted by sodium, potassium and hydrogen bromides, were used under a variety of condition of catalyst concentration, temperature, oxygen flow and piperylene purity. Under all conditions studied, a large number of oxidation products were formed. Maximum yields of 2,4-pentadienoic acid were obtained using a cobalt acetate bromide catalyst at 85°C.

Oxidation Of Thin Silver Films By Ozone And Atomic Oxygen, Lawrence R. Thorne

Undergraduate Honors Capstone Projects

Recently, thin silver film detectors have been used to determine atomic oxygen profiles in the 70-100 km region of the upper atmosphere. The detectors' sensitivity to atomic oxygen is the result of the formation of silver oxide(s) which cause their electrical resistance to increase. A common procedure to calibrate and to make these detectors more sensitive is to cycle them through a series of three or more oxidations and reductions. This paper indicates that this cycling makes silver films more sensitive to ozone, causing them to be usable only at heights greater than 38 km. Also reported herein are experimentally …

Estimations Of The Effective Electrolytic Surface Area Of Rough And Porous Silver Electrodes ; Ii. Potentiostatic Oxidation Of Silver In Alkaline Electrolyte, James Glenn Bearss

Theses and Dissertations

This dissertation is written in two sections. The first section deals with the development of methods for the estimation of the effective electrolytic surface area of rough and porous silver electrodes in alkaline electrolyte. Data are presented comparing the results of three different methods of surface area estimation. Model pore electrodes were also prepared and oxidized to study the reactions in a pore. Data for constant current oxidations of these electrodes is given. The second section deals with the potentiostatic oxidations of silver in alkaline electrolyte. Data are presented on the total charge acceptance versus applied potential for a potential …

The Influence Of Temperature And Some Other Factors On The Biological And Nonbiological Oxidation Of Chalcopyrite, Pyrite And Copper Sulfide, Ezra Revier Palmer

Theses and Dissertations

The purpose of this study was: (1) to find the effect of temperature on the wet oxidation of chalcopyrite, pyrite, and copper sulfide over the biological and nonbiological range; (2) to determine the influence of ferrous and ferric iron and free oxygen(air) on the oxidation. The sulfide minerals studied were oxidized over a range of temperatures between 25° to 75° C. The optimum biological oxidation occurred near 35° C. The nonbiological oxidation was very slow at low temperatures but increased with increasing temperature. The effect of solutions used in leaching the various sulfides over the temperature range differred. A synthetic …

Stability And Concentration Effects In The Use Of Siloxene As A Chemiluminescent Indicator In Redox Titrations, William F. Burkhardt

Chemistry Honors Papers

This 22 page thesis attempts to determine the limitations of, and to extend the applicability of siloxene as a chemiluminescent indicator in redox titrations.

Separation And Identification Of The 2,4-Dinitrophenylhydrazones Of The Oxidation Products Of Glycerol., Gwendolyn Parker Mcclure

Electronic Theses and Dissertations

No abstract provided.

A Study Of Chrome Dyeing By Determination Of Chromium On Dyed Wool And In Exhausted Dye Baths, Thomas Schonfeld

Chemistry Honors Papers

This 13 page thesis attempts to analyze the reaction between the wool and the chromate in the dye bath.

Iron And Cobalt Salts As Catalysts In The Oxidation Of Sodium Sulfite By Free Oxygen, Loren C. Bryner

Theses and Dissertations

The present investigation was carried out to show the catalytic effect of some iron and cobalt salts on the oxidation of sodium sulfite solutions by free oxygen. The rate of reaction was determined by measuring the volume of water required to replace the absorbed oxygen. A photograph and diagrammatical arrangement of the apparatus is given, (Page 14). From the preliminary experiments it was found that the rate of oxidation of sodium sulfite solutions is dependent upon concentration, and speed of the shaker.

Volumetric Chemical Analysis, Beatrice Brooks

Chemistry Honors Papers

This 20 page thesis illustrates various methods of volumetric processes.