Chemistry Commons^™

Electrical Properties Of Plasma-Polymerized Thin Organic Films, Maciej Gazicki, H. Yasuda

Chemistry Faculty Research & Creative Works

The electrical properties of plasma-polymerized films are summarized and compared to those of conventional polymers. Particular attention is devoted to the dielectric relaxation, dielectric breakdown, electric conductivity and photoconductivity, and their control via control of the plasma parameters. © 1983 Plenum Publishing Corporation.

Transport Properties Of Ground State Nitrogen Atoms, James C. Rainwater, Louis Biolsi Jr., Kevin J. Biolsi, Paul M. Holland

Chemistry Faculty Research & Creative Works

Transport properties of dilute monatomic gases depend on the two body atom-atom interaction potential. When two ground state (⁴S) nitrogen atoms interact, they can follow any of four potential energy curves corresponding to the N₂ molecule; the X ¹Σ⁺_g, A³Σ⁺_u, ⁵Σ⁺_g, and ⁷Σ⁺_u curves. Transport collision integrals for the ¹Σ⁺_g and ³Σ⁺_u states have been calculated by representing the potentials for these states with the Hulburt-Hirschfelder potential. The⁵Σ⁺_g state has a …

Evaluation Of A New Silicone-Methane Polymer Contact Lens, Jeffrey E. Koziol, Gholam A. Peyman, Hirotsuga Yasuda

Chemistry Faculty Research & Creative Works

A new gas permeable contact lens is produced using a solid silicone core and a plasma polymer surface. This surface is hydrophilic and impermeable to macromolecules. The surface characteristics of this lens were compared with the surface characteristics of available silicone contact lenses. We found that in contrast to our lens, the silicone contact lenses lost their hydrophilic surface with time. In addition, they are permeable to lipid dyes, eg, Sudan red. © 1983 Arch Ophthalmol All rights reserved.

Intermolecular Interactions For Phosphatidyl Choline And Phosphatidyl Ethanolamine, Tony Flaim, Stig Friberg, Patricia L.M. Plummer

Chemistry Faculty Research & Creative Works

Intermolecular interaction between pairs of methylphosphocholine (MPC) and methylphosphoethanolamine were calculated using an extended CNDO/2 program. Experimentally determined conformations were used for the ethanolamine and choline groups. In the methylphosphocholine the major interaction was intramolecular, involving the phosphate ester-choline groups, while in the ethanolamine the maximum attraction was intermolecular between the ethanolamine and the phophate ester of a neighboring molecule(s). © 1983.

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.

Metal Ion Oxidative Decarboxylations. 13.¹ Kinetics And Mechanisms Of The Oxidation Of N-Benzyliminodiacetic Acid With Cerium(Iv) In Acidic Perchlorate And Acidic Sulfate Media2, Samir B. Hanna, Marilyn E. Moehlenkamp

Chemistry Faculty Research & Creative Works

The Ce(IV)-mediated decarboxylation of N-benzyliminodiacetic acid (BIDA) produces benzaldehyde, formaldehyde, dimethylamine, benzylmethylamine, and N-benzylglycine in acidic perchlorate and acidic sulfate media. Spectrophotometric evidence of an intermediate Ce(IV)-BIDA complex is given. The data may be interpreted in terms of a mechanism which involves sequential reactions, the first of which is a reversible reaction: BIDA + Ce(IV) (k1) ⇄ (k-1) complex (k2) → products. The rapid complex formation is followed by a slower oxidative decomposition to give a free radical capable of inducing free-radical polymerization. The free radical reacts rapidly with another Ce(IV) to give an iminium ion which undergoes either hydrolysis …

Cerebral Embolism In The Michael Reese Stroke Registry, L. R. Caplan, D. (Daniel) B. Hier, I. D'Cruz

Chemistry Faculty Research & Creative Works

Infarction Secondary to Cerebral Embolism Was Diagnosed in 127 (23.5%) of 540 Patients in the Michael Reese Stroke Registry. Coronary Artery Disease, Atrial Fibrillation, Valvular Heart Disease, Mitral Annulus Calcification, and Cardiomyopathy Were the Commonest Etiologies. Echocardiography Documented a Potential Embolic Source in 7 Patients Without Previously Known Heart Disease and Clarified the Cardiac Pathology in Many of the Patients with Known Heart Disease. the Left Anterior Circulation Was Affected in 48%, Right Anterior in 37%, and Posterior Circulation in 15% of patients. CT Was Abnormal in 71% of the Patients and Was Approximately Equally Helpful in All Locations. Nineteen …

Thermal Decomposition Kinetics Of Iodine‐Doped Polyacetylene In Vacuum, J. ‐E Osterholm, H. Yasuda, L. L. Levenson

Physics Faculty Research & Creative Works

The thermal stability of iodine‐doped polyacetylene films, (CHIy)x, has been studied by means of electrical conductivity measurements, measurements on weight loss, and mass spectrometric analysis of desorbing species. When heated between room temperature and 125°C in vacuum, these films proved to be of poor thermal stability, being unstable at temperatures above 20°C. During the thermal treatments, molecular iodine desorbs from the films, resulting in an appreciable dopant weight loss with accompanying decrease in the electrical conductivity. The decomposition process does not follow simple kinetics. Copyright © 1983 John Wiley & Sons, Inc.

Binary Collision Dynamics And Numerical Evaluation Of Dilute Gas Transport Properties For Potentials With Multiple Extrema, James C. Rainwater, Paul M. Holland, Louis Biolsi

Chemistry Faculty Research & Creative Works

Prediction of gaseous transport properties requires calculation of Chapman-Enskog collision integrals which depend on all possible binary collision trajectories. The interparticle potential is required as input, and for a variety of applications involving monatomic gases the Hulburt-Hirschfelder potential is useful since it is determined entirely from spectroscopic information and can accomodate the long-range maxima and minima found in many systems. Hulburt-Hirschfelder potentials are classified into five distinct types according to their qualitative binary collision dynamics, which in general can be quite complex and can exhibit “double orbiting”, i.e., a pair of orbiting impact parameters for a single energy of collision. …

Structural And Magnetic Properties Of Y(Al₁₋ₓfeₓ)₁₂, Ying-Chang Yang, Gary J. Long, William Joseph James, R. Yeh

Chemistry Faculty Research & Creative Works

In order to investigate the magnetic behavior of 3d atoms in the ThMn₁₂‐type structure, the structured and magnetic properties of Y(Al_1-xFe_x)₁₂ were studied by Mössbauer spectroscopy and magnetization measurements. The Y(Al_1-xFe_x)₁₂ intermetallic compounds crystallize in the ThMn₁₂‐type structure for x in the range of 0.3-0.5. The results can be explained on the basis of the preferential atomic ordering observed in the ternary compounds. The compounds are ferromagnetic with Curie temperatures of 130, 170, and 280 K, respectively, for x values of 0.3, 0.4, and 0.5.

Preparation Of Cationic Polymer Surfaces By Grafting Polymerization, H. Yasuda, B. Sherry, M. A. Ei‐Nokaly, Stig Friberg

Chemistry Faculty Research & Creative Works

A cationic polymer surface with extensive capacity for adsorption of anionic surfactants was prepared by graft polymerization of vinyl pyridine onto a plasma‐treated polypropylene surface. The nitrogen was quaternized in order to obtain the cationic sites. The concentration dependence of adsorption from high eletrolyte solution of the anionic surfactant was similar to the one a solid surface from solutions with no added electrolyte. The hydrophobic contribution to the adsorption was experienced at surfactant concentrations far below its critical micellization. Copyright © 1982 John Wiley & Sons, Inc.

Biomedical Applications Of Plasma Polymerization And Plasma Treatment Of Polymer Surfaces, H. Yasuda, M. Gazicki

Chemistry Faculty Research & Creative Works

Thin polymer films obtained by plasma polymerization usually show good biocompatibility when compared to classical biomaterials such as Silastic. The thicknesses of these films (from several hundreds of Å to several μm) make them suitable for the purpose of changing the surface properties of the substrate without altering its bulk properties. Both the above features together indicate the possible Biomedical use of plasma polymerization as well as plasma treatment of polymer surfaces processes. The purpose of this review is to present the most significant efforts to develop such applications with the specification of particular fields where these efforts are directed. …

Current Concepts Of Cerebrovascular Disease - Stroke: Stroke And Drug Abuse, L. R. Caplan, D. (Daniel) B. Hier, G. Banks

Chemistry Faculty Research & Creative Works

This Review Summarizes Available Information Concerning Cerebral Vascular Complications of the Most Commonly Abused Substances and Discusses Possible Mechanisms of Vascular Injury and Cerebral Damage. Although Alcohol is Frequently Abused and May Have Important Cerebrovascular Effects, its Consideration is Beyond the Scope of This Review.

A Study Of Poly(P‐Xylylene)‐Coated Asf5‐Doped Polyacetylene, J. E. Osterholm, H. Yasuda, L. L. Levenson

Physics Faculty Research & Creative Works

Electrical conductivity measurements and scanning electron microscopy have been used to study uncoated and poly(p‐xylylene)‐coated samples of polyacetylene doped with AsF5. These initial results indicate a considerable reduction in the decay rate of conductivity in the presence of oxygen as well as a decreased rate of thermal decomposition of the dopant when heated between 50°C and 115°C in vacuum by the coating. Copyright © 1982 John Wiley & Sons, Inc.

A Potential Problem With The Tsi Electrostatic Aerosol Classifier, Darryl J. Alofs, Max B. Trueblood

Mechanical and Aerospace Engineering Faculty Research & Creative Works

No abstract provided.

Structural And Magnetic Properties Of Co(Urea)₂Cl₂·2h₂O: A Two-Dimensional Lsing System With Hidden Canting, Richard Lewis Carlin, Kyong O. Joung, Andries Van Der Bilt, H. Den Adel, Charles J. O'Connor, Ekkehard Sinn

Chemistry Faculty Research & Creative Works

The characterization of Co(urea)₂Cl₂·2H₂O is reported. The crystal structure at ambient temperatures yields the following information: the chlorine, water, and urea group are coordinated, the urea being bound via the oxygen, to form an octahedral environment about the metal atom. Intermolecular hydrogen bonds between the coordinated chlorine and water ligands produce parallel infinite sheets which provide a two-dimensional exchange pathway. The sheets are separated by the urea ligands and may be considered as magnetically isolated from one another. Crystal data: space group P2₁/c, Z = 2, α = 7.397 (3) Å, b …

Adhesion Of Glow Discharge Polymers To Metals And Polymers, N. Inagaki, H. Yasuda

Chemistry Faculty Research & Creative Works

Adhesion of glow discharge polymers to metals and polymers in an adhesive joint was measured by lap‐shear test and immersion in hot water of 70°C for an extended time. A glow discharge polymer was deposited onto polymers [polyethylene and poly(tetrafluoroethylene)] and metals (aluminum and stainless steel) prior to when the polymer and metal were joined. It is found that the lap‐shear strength is enhanced by coating the surfaces of these substrates with plasma film produced from methane, ethylene, and acetylene, and that deterioration of the adhesive bonding part, when immersed in hot water of 70°C, is strongly dependent on the …

Similarity In Phase Diagrams Between Ionic And Nonionic Surfactant Solutions At Constant Temperature, K. Shinoda, H. Kunieda, N. Obi, Stig Friberg

Chemistry Faculty Research & Creative Works

No abstract provided.

The Effect Of Plasma-Deposited Polymers On The Nucleate Boiling Behavior Of Copper Heat Transfer Surfaces, T. Hinrichs, E. Hennecke, H. Yasuda

Chemistry Faculty Research & Creative Works

The effect of plasma deposited polymers on the nucleate boiling behavior of copper heat transfer surfaces, using water as the boiling liquid, was determined. The monomers used were tetrafluoroethylene (TFE) and methane. It was found that an 18 nm thick coating of TFE enhanced the nucleate boiling, while a 150 nm thick coating reduced the nucleate boiling. Both 15 nm and 150 nm thick coatings of methane reduced the nucleate boiling, with the effect being more pronounced with the thicker coating. A surface energy effect is postulated to explain the enhanced boiling observed. © 1981.

Distribution Of Polymer Deposition In Glow Discharge Polymerization In A Capacitively Coupled System, N. Inagaki, H. Yasuda

Chemistry Faculty Research & Creative Works

The manner by which polymers created by plasma uniformly deposit onto substrates was sought. By rotating the substrate placed midway between electrodes, completely uniform distribution of polymer deposition was accomplished, and the deviation of the polymer deposition in a radius direction of the rotating substrate was within experimental errors. Materials of the substrate on which the polymer deposited had no influence on uniformity of polymer deposition, but the electrical circuit of power source, i.e., grounding an electrode, markedly disturbed the uniformity. Thickness of polymers deposited on the substrate was linearly proportional to reaction time. Surface energies of deposited polymers prepared …

Glow Discharge Polymerization., H. Yasuda

Chemistry Faculty Research & Creative Works

In this review-paper the author summarizes some important aspects of ″polymer formation″ in the glow discharge polymerization or plasma polymerization, rather than presenting a bibliographical review of work. It is shown that glow discharge polymerization can be visualized as a process consisting of three discharge processes. These are (1) controlled discharge of monomer, (2) electric discharge (glow discharge), and (3) glow discharge polymerization of the monomer. Before the electric discharge is initiated, a steady-state flow of the monomer is generally established. During this controlled discharge of the monomer (without electric discharge), adsorption of the monomer onto the solid surfaces in …

The Initial And Terminating Stage Of Glow Discharge Polymerization Investigated By Thickness Monitor, N. Inagaki, H. Yasuda

Chemistry Faculty Research & Creative Works

An attempt to discuss the initial stage and terminating stage of glow discharge polymerization was made by selecting the monomer system of styrene and acetylene, which differ in their condensability, and a certain polymerization procedure. Results indicate the important aspects of the initial and terminating stages of glow discharge polymerization. These aspects may not play a significant role in the study of bulk properties of plasma‐polymerized polymers or in the study of polymer deposition rate. However, the initial stage effect might influence the adhesion of the polymer. The terminating stage effect might influence the surface characteristics of glow discharge‐polymerized polymers. …

The Structure Of Lamellar Lyotropic Liquid Crystals From Lecithin And Alkanediols, Magda A. El-Nokaly, Larry D. Ford, Stig Friberg, David W. Larsen

Chemistry Faculty Research & Creative Works

Lamellar liquid crystals from lecithin and alkane diols were studied to determine the composition range of stability and geometrical dimensions using low-angle X-ray scattering. An estimation of the dislocation pattern was made from the optical pattern in polarized light. The ethylene glycol gave the widest range of stability for the lamellar structure, the range being reduced toward heptane diol, the longest member to give liquid crystals. The interlayer spacing was reduced with increasing chain length of the diol and the dislocation pattern remained identical. © 1981.

Neutron Activation Analysis Of Nuclides From Stellar And Man-Induced Nuclear Reactions, Lawrence Lee Oliver

Doctoral Dissertations

"Neutron activation and γ-counting were used to determine the relative abundances of six stable tellurium isotopes in the acid-etched residues of the Allende meteorite. The results were correlated with the isotopic compositions of xenon and the elemental abundances of helium and neon in similarly prepared residues. Nucleosynthesis appears to be the only viable explanation for the anomalous isotopic and elemental compositions observed in these residues. Our results suggest that the solar system condensed from an isotopically and chemically zoned nebula that was produced by the explosion of a supernova, concentric with the present sun.

A combination of neutron activation and …

Thermal Decomposition Kinetics Of Asf5-Doped Polyacetylene In Vacuum, T. Inoue, J. E. Osterholm, H. Yasuda, L. L. Levenson

Physics Faculty Research & Creative Works

Electrical conductivity measurements, mass spectra of desorbing species, and ESCA surface analysis are reported for AsF5-doped polyacetylene heated between 50 and 130°C in vacuum. All measurements indicate first-order decomposition kinetics with activation energies between 13 and 20 kcal mole-1. Decomposition leads to the desorption of AsF3 and F2. Metallic arsenic remains in the polyacetylene as a decomposition by-product.

Evidence For An Iminium Cation Intermediate And Its Non‐Oxidative Decarboxylation In A Cerium (Iv)‐Mediated Oxidative Decarboxylation. Preliminary Communication, Samir B. Hanna, Marilyn E. Moehlenkamp

Chemistry Faculty Research & Creative Works

Evidence is provided for the occurrence of a non‐oxidative decarboxylation in an iminium cation intermediate which is produced in an oxidative decarboxylation induced by cerium (IV). Copyright © 1980 Verlag GmbH & Co. KGaA, Weinheim

Mobility Of Solvent Molecules In A Nonaqueous Lyotropic Liquid Crystal, David W. Larsen, Stig Friberg, Hugo Christenson

Chemistry Faculty Research & Creative Works

No abstract provided.

Spectroscopic Investigation Of The Mutual Interactions Between Nonionic Surfactant, Hydrocarbon, And Water, Hugo Christenson, Stig Friberg

Chemistry Faculty Research & Creative Works

NMR, UV, and IR spectroscopy were used to determine the interactions in hydrocarbon solutions between polyethylene glycol alkyl ethers, water, and aromatic hydrocarbons. The results showed a concentration dependence for the site of benzene in benzene/surfactant solutions. At low concentrations the benzene molecules were preferentially located adjacent to the surfactant oxyethylene chain with an even distribution along the chain. At high benzene concentrations a positive concentration gradient was found toward the hydrocarbon end of the oxyethylene chain. Addition of water increased this gradient except for the octa ethylene glycol dodecyl ether; for this compound the preferential water location appeared to …

Nmr Investigations Of Aggregation Of Nonionic Surfactants In A Hydrocarbon Medium, Hugo Christenson, Stig Friberg, David W. Larsen

Chemistry Faculty Research & Creative Works

Proton NMR, carabon-13 NMR, light-scattering, and density measurements were used to investigate association structures and molecular interactions during water solubilization in polyoxymethylene dodecyl ether/benzene systems at high surfactant concentrations. The results indicated an absence of association aggregates at low water concentrations. At water contents between 10 and 20%, association structures started to form, probably micelles of the inverse type, in which the water-polyoxymethylene chain interaction is the predominant feature. There is evidence that the average chain conformation changes with water content, and that bound water molecules are distributed evenly along the polyethoxyethylene chain. At higher water concentration, the results indicated …

Crystal Structures Of A₂Fecl₅·H₂O (A=Rb⁺, Cs⁺) And Field Dependent Superconducting Susceptometer Measurements, Charles J. O'Connor, Bascom Sine Deaver, Ekkehard Sinn

Chemistry Faculty Research & Creative Works

Crystal structures and low field principal crystal axis magnetic measurements are reported for the antiferromagnetic iron (III) salts A₂FeCl₅·H₂O; A=Rb⁺, Cs⁺. The two compounds undergo a zero field paramagnetic to antiferromagnetic phase transition at 6.5 K (A=Cs⁺) and 10.05 K (A=Rb⁺). The spin flop magnetic phase is observed in high field measurements. The magnetic field-temperature phase diagrams are reported. All magnetic measurements were recorded on a superconducting susceptometer. The bicritical points are 6.25 K, 14.5 kOe (A=Cs⁺), 9.75 K, 17.8 KOe (A=Rb⁺). …