| Analytical Utility of Cylindrical Microelectrodes |
31 MAY 89 |
34 pages |
| Authors:
Scott T. Singleton; John J. O'Dea; Janet Osteryoung; STATE UNIV OF NEW YORK AT BUFFALO AMHERST
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 | The behavior and utility of a platinum microelectrode is demonstrated for the cylindrical geometry. The working electrode used here is a small platinum wire (25 micro m in diameter and 0.5 to 1.0 cm in length) which is sealed in a 2 micro L glass microcapillary pipet. Mass transport to a stationary cylinder in quiescent solution is governed by axi-symmetrical cylindrical diffusion. Various experiments (chronoamperometry and cyclic staircase and square-wave ... |
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| Experimental Determination of the Coefficient in the Steady State Current Equation for Spherical Segment Microelectrodes |
31 MAY 89 |
20 pages |
| Authors:
Zbigniew Stojek; Janet Osteryoung; STATE UNIV OF NEW YORK AT BUFFALO AMHERST
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| The coefficient in the steady state current equation for spherical segment microelectrodes has been evaluated experimentally for various values of the height of the spherical segment. For this purpose chronoamperometric reduction of Hg2+2 ion at a silver microdisc electrode in perchloric acid solution has been employed. The diffusion coefficient of Hg2+2 in 0.25 M HC104 at 30 C was determined as .0000112 sq.cm/s. Microelectrodes, Spherical segment electrodes, Steady state, Mercury. ... |
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| Corrosion Measurements Using Microelectrodes |
08 JUL 88 |
33 pages |
| Authors:
Kazimierz Wikiel; Janet Osteryoung; STATE UNIV OF NEW YORK AT BUFFALO DEPT OF CHEMISTRY
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| It is shown microelectrodes can be substituted for large area area electrodes in typical corrosion measurements. Results obtained for copper and iron in concentrated solutions are consistent with earlier literature report. Application of microelectrodes markedly reduces effects of IR-ohmic drops. It allows one to apply electrochemical methods in corrosion investigations under conditions closer to those of natural corrosion environments. The corrosion rate of circular copper microelectrodes in 0.1 mol/dm 3 ... |
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| Determination of Kinetic Parameters from Steady-State Microdisk Voltammograms |
88 |
14 pages |
| Authors:
Z. Galus; J. Golas; Janet Osteryoung; STATE UNIV OF NEW YORK AT BUFFALO DEPT OF CHEMISTRY
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| Equations are derived for the voltammetric response of an irreversible system in the steady-state regime at a small electrode. Voltammetric data for oxidation of Fe(II) in 0.1 M H2SO4 at circular platinum electrodes of radius 5 and 12.5 micro are analyzed by a semilogarithmic technique and by reciprocal plots analogous to treatments of rotating disk voltammograms. The resulting values of kinetic parameters are standard rate constant ks = (1.5 + ... |
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| Electrodeposition and Anodic Stripping of Silver on Single Carbon Fibers |
25 SEP 86 |
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| Authors:
Janusz Golas; Janet Osteryoung; STATE UNIV OF NEW YORK AT BUFFALO DEPT OF CHEMISTRY
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 | Silver is deposited electrolytically on carbon fibers from acetate buffer (1.25 M KOAc/1.70 M HOAc) in the potential range -0.3 to -0.8 V vs SCE. Chronoamperometric and cyclic voltammetric measurements confirm that the the mechanism of deposition is nucleation; the rate is higher than at large circular glassy carbon electrodes. The silver deposits are more stable, especially with respect to oxidation by air, than are similar deposits for mercury. Preliminary ... |
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| Carbon Fiber Microelectrodes as Substrates for Mercury Films |
25 SEP 86 |
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| Authors:
Janusz Golas; Janet Osteryoung; STATE UNIV OF NEW YORK AT BUFFALO DEPT OF CHEMISTRY
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| Conditions for mercury deposition at cylindrical carbon fiber microelectrodes were examined and presented together with a new construction of electrodes were examined and presented together with a new construction of electrode body and the manner in which the fiber is held. Data obtained in KSCN and acetate buffer solutions suggest that in order to obtain linear dependence of square wave stripping peak vs. mercury concentration the amount of the deposit ... |
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| Arrays of Very Small Voltammetric Electrodes Based on Reticulated Vitreous Carbon |
14 OCT 1983 |
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| Authors:
Neal Sleszynski; Janet Osteryoung; Malcolm Carter; STATE UNIV OF NEW YORK AT BUFFALO AMHERST
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| Micro-electrode arrays constructed from reticulated vitreous carbon are described and characterized. Sterological analysis and cyclic voltammetric data indicate the arrays have equivalent radii as small as 32 microns, with densities as high as 1650 electrodes/sq cm. |
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| Interaction of Methylated Adenine Derivatives with the Mercury Electrode |
30 APR 1982 |
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| Authors:
Emil Palecek; Janet Osteryoung; R. A. Osteryoung; STATE UNIV OF NEW YORK AT BUFFALO DEPT OF CHEMISTRY
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| Adenine and its methylated derivatives, 1-methyl-6-aminopurine, 3- methyl-6 aminopurine, N-methyl-6-aminopurine, and N,N-dimethyl-6-aminopurine, were studied in alkaline solution by DC, normal pulse and differential pulse polarography and by cyclic voltammetry and cathodic stripping voltammetry at hanging mercury drop electrodes. All save N, N-dimethyl-6-aminopurine gave polarographic mercury drop electrodes. All save N, N-dimethyl-6-aminopurine gave polarographic currents anc cathodic stripping peaks due to the formation of slightly soluble compounds with mercury. It was ... |
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| Chronoamperometric Transients at the Stationary Disk Microelectrode |
30 NOV 1981 |
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| Authors:
Tadeusz Hepel; Janet Osteryoung; STATE UNIV OF NEW YORK AT BUFFALO DEPT OF CHEMISTRY
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| Chronoamperometric transients for diffusion controlled reactions at stationary platinum and gold microelectrodes have been examined. The results are compared with those predicted theoretically for hemispherical electrodes and for disk electrodes. The hemispherical model was found to describe the current-time transients only qualitatively, while excellent agreement was obtained between the theory for a stationary disk and data for the hexacyanoferrate (II)/(III) redox reaction. Equations for mass transport to a stationary disk ... |
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| Diffusion-Controlled Current at the Stationary Finite Disk Electrode. Theory. |
OCT 1980 |
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| Authors:
Koichi Aoki; Janet Osteryoung; STATE UNIV OF NEW YORK AT BUFFALO DEPT OF CHEMISTRY
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| Rigorous expressions for diffusion-controlled currents at a stationary finite disk electrode are derived through use of the Winer-Hofp technique. The chronoamperometric curve obtained varies smoothly from a curve represented by the Cottrell equation to a steady state value similar to that obtained for a spherical electrode as time elapses. The solution can be expressed also as the Cottrell term multiplied by a power series in the parameter sq. rt (Dt/a), ... |
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| Diffusion Controlled Current at a Stationary Finite Disk Electrode. Experiment. |
AUG 1980 |
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| Authors:
Koichi Aoki; Janet Osteryoung; STATE UNIV OF NEW YORK AT BUFFALO DEPT OF CHEMISTRY
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| Micro disk electrodes were constructed from glassy carbon electrodes coated with photo resist by using conventional photolithography. Chronoamperometric measurements were made at these electrodes in the system ferrocyanied/ferricyanide. Dependence of currents on time and on radii of the electrodes was in good agreement with that predicted by the theory presented previously. (Author) |
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