• Bulletin of the Korean Chemical Society
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• v.13 no.4
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• pp.419-425
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• 1992

Conducting polypyrrole doped with iron (Ⅱ,Ⅲ) hexacyanate Fe$(CN)_6^{z-}$ ions was studied for its physical and electrochemical properties. The polymer exhibited two pairs of waves in the cyclic voltammogram, one for the reversible oxidation/reduction of the incorporated iron hexacyanate ions and the other for the near-reversible oxidation/reduction of the polypyrrole moiety. The exchange of ions incorporated in the polymer and other ions present in solutions were examined by following the decrease of the reversible redox peaks of Fe$(CN)_6^{z-}$, and by EDX analysis. The spin density of this highly conducting polymer as probed by ESR spectroscopy was extremely low compared to polypyrrole doped with common anions.

• Journal of the Korean Applied Science and Technology
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• v.20 no.2
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• pp.94-100
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• 2003

We studied electrochemical characteristics of Langmuir-Blodgett(LB) films by using cyclic voltammetry with a three-electrode system. An Ag/AgCl as a reference electrode, a platinum wire as a counter electrode and LB film-coated indium tin oxide(ITO) as a working electrode were used to study electrochemical characteristics at a various concentration of $NaClO_4$ solution. LB films were reduced from initial potential to -1350 mV, continuously oxidized to l650mV and returned to the initial point. The scan rate was l00mV/s. The monolayer surface morphology of the LB film have been measured by Atomic Force Microscope(AFM). As a result, We comfirmed that the microscopic properties of LB film by AFM showed the good orientation of momolayer molecules and the thickness of monolayer was 3.5-4.lnm. The cyclic voltammograms(CV) of the ITO-coated glass showed the peak potentials for the reduction-oxidation reation. LB films of 4-octyl-4'-(5-carboxypentamethyleneoxy) azobenzene(8A5H) / L-${\alpha}$-phosphayidyl choline, dilauroyl(DLPC) seemed to be irreversible process caused by only the oxidation current from the cyclic voltammogram. The current of oxidatation increased at cyclic voltammogram by increasing 8A5H density in LB films. The diffusivity(D) of LB films increased with increasing of a 8A5H amount and was inversely proportional to the concentration of $NaClO_4$ solution.

• Journal of the Korean Electrochemical Society
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• v.7 no.4
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• pp.201-205
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• 2004

The Pt-Ru electrocatalyst was Prepared on Nafion membrane modified with Polypyrrole by chemical reduction of $H_2PtCI_6\;and\;RuCl_3$ solution ai precursor. From the electron dispersive microanalysis spectroscope(EDS), the Pt-Ru catalyst was located on the surface of Ppy/Nafion composite. The electrochemical oxidation of methanol on Pt-Ru catalyst deposited in Polypyrrole-impregnated Nafion was investigated by cyclic voltammetry (CV) and chronoamperometry. The onset potential of methanol oxidation was shifted to negative potential as the $RuCI_3$ concentration in deposition solution. Also, it was known that the Pt-Ru binary catalyst on Nafion could be directly deposited by using Polypyrrole and resulting Pt-Ru/PPy/Nafion was available for methanol oxidation.

• Korean Journal of Materials Research
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• v.25 no.3
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• pp.113-118
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• 2015

To improve the methanol electro-oxidation in direct methanol fuel cells(DMFCs), Pt electrocatalysts embedded on porous carbon nanofibers(CNFs) were synthesized by electrospinning followed by a reduction method. To fabricate the porous CNFs, we prepared three types of porous CNFs using three different amount of a styrene-co-acrylonitrile(SAN) polymer: 0.2 wt%, 0.5 wt%, and 1 wt%, respectively. A SAN polymer, which provides vacant spaces in porous CNFs, was decomposed and burn out during the carbonization. The structure and morphology of the samples were examined using field emission scanning electron microscopy and transmission electron microscopy and their surface area were measured using the Brunauer-Emmett-Teller(BET). The crystallinities and chemical compositions of the samples were examined using X-ray diffraction and X-ray photoelectron spectroscopy. The electrochemical properties on the methanol electro-oxidation were characterized using cyclic voltammetry and chronoamperometry. Pt electrocatalysts embedded on porous CNFs containing 0.5 wt% SAN polymer exhibited the improved methanol oxidation and electrocatalytic stability compared to Pt/conventional CNFs and commercial Pt/C(40 wt% Pt on Vulcan carbon, E-TEK).

• Journal of the Korean Applied Science and Technology
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• v.27 no.3
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• pp.361-369
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• 2010

A study on the corrosion inhibition of metals is important in many industrial applications (carbon steel, copper, aluminum, SUS 304, nickel). In this study, we investigated the C-V diagrams related to the surface corrosion of metals. It was observed through the SEM that the surface corrosion state of the various metals had the corrosion potential by the scan rate and the organic inhibitor containing an amine group. We determined to measure cyclic voltammetry using the three-electrode system. The measurement of oxidation and reduction ranged from -1350mV to 1650mV. The scan rate was 50, 100, 150, and 200mV/s. It turned out that the C-V characterization of SUS 304 was irreversible process caused by the oxidation current from the cyclic voltammogram. After adding organic inhibitors, the adsorption film was constituted, and the passive phenomena happened. As a result, it was revealed that the inhibition effect of metal corrosion depends on the molecular interaction, and the interaction has influence on the adsorption complex.

• Applied Chemistry for Engineering
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• v.22 no.5
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• pp.479-485
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• 2011

Pt-Bi/C catalysts supported on carbon black with various Pt/Bi ratios were synthesized by a reduction method. Chloroplatinic acid hydrate ($H_2PtCl_6{\cdot}xH_2O$) and bismuth (III) nitrate pentahydrate ($Bi(NO_3)_3{\cdot}5H_2O$) were used as precursors for Pt and Bi, respectively. Before loading metal on carbon, heat treatment and pretreatment of carbon black in an acidic solution was conducted to enhance the degree of dispersion. The physical property of the synthesized catalysts was investigated by X-ray diffraction and X-ray photoelectron spectroscopy. The XRD pattern of untreated Pt-Bi/C catalyst showed BiPt and $Bi_2Pt$ peaks in addition to Pt peaks. These results imply that Bi atoms were incorporated into the Pt crystal lattice by Pt-Bi alloy formation. The catalytic activity for methanol oxidation was measured using cyclic voltammetry in a mixture of 0.5 M $H_2SO_4$ and 0.5 M $CH_3OH$ aqueous solution. The addition of proper amount of Bi was found to significantly improve catalytic activity for methanol oxidation. The catalytic activity for methanol oxidation was closely related to the stability between electrode and electrolyte. In order to investigate the stability of catalysts, chronoamperometry analysis was carried out in the same solution at 0.6 V.

• Journal of the Korean Chemical Society
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• v.37 no.4
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• pp.401-407
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• 1993

The titanium oxide thin films were prepared by air oxidation and water vapor oxidation. The electrochemical properties of the electrodes were studied in 1M NaOH solution. The peak potentials of oxygen reduction from cyclic voltammogram techniques were observed at aroung -0.9 ∼ -1.0 V vs. SCE and the reaction was totally irreversible process. The electrochemical properties of titanium dioxide electrodes prepared by water vapor oxidation exhibited different from the air oxidized electrodes, but it was similar to single crystal $TiO_2$. The peak potentials of oxygen reduction were observed at slightly more positive than flat band potentials and depended on pH.

• Textile Coloration and Finishing
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• v.20 no.5
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• pp.41-46
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• 2008

Recently, computational calculation of molecular energy potentials and electrochemical reduction/oxidation behaviors are of very importance in view point of prediction of dye's properties such as energy levels and bandgaps of absorption. This can be influenced by their different constituents or substituents in chromogen molecules. Structural conformations and properties with computational modeling calculation are numerically simulated, which are fully or partly based on fundamental laws of physics. In addition, cyclic voltammetric measurement was used to obtain the experimental redox potential values, which were compared to the computed simulation values.

• Journal of the Korean Applied Science and Technology
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• v.29 no.3
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• pp.421-428
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• 2012

We investigated an electrochemical properties for Langmuir-Blodgett (LB) nano-films of polyimide and phospholipid mixture. LB films of polyamic acid and phospholipid monolayer were deposited by the Langmuir-Blodgett method on the indium tin oxide(ITO) glass. The electrochemical properties measured by cyclic voltammetry with three-electrode system(an Ag/AgCl reference electrode, a platinum wire counter electrode and LB film-coated ITO working electrode) in $KClO_4$ solution. The current of reduction and oxidation range was measured from 1650 mV to -1350 mV, continuously. The scan rates were 50, 100, 150, 200 and 250 mV/s, respectively. As a result, monolayer LB films of polyamic acid and phospholipid mixture was appeared on irreversible process caused by the reduction current from the cyclic voltammogram. Diffusion coefficient (D) effect in the polyamic acid and phospholipid mixture was used in the LAPC with LLPC fewer than the diffusion coefficient values.

• Journal of the Korean Applied Science and Technology
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• v.30 no.1
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• pp.64-70
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• 2013

We investigated an electrochemical properties for Langmuir-Blodgett (LB) monolayer films of sphingomyelin and polyamic acid(1:1 molar ratio) mixture. LB monolayer films of mixture was deposited by the LB method on the indium tin oxide(ITO) glass. The electrochemical properties measured by cyclic voltammetry with three-electrode system in $KClO_4$ solution. The current of reduction and oxidation range was measured from 1650 mV to -1350 mV, continuously. The scan rates were 50, 100, 150, 200 and 250 mV/s, respectively. As a result, LB monolayer films of sphingomyelin and polyamic acid mixture was appeared on irreversible process caused by the reduction current from the cyclic voltammogram. Diffusion coefficient (D) in the sphingomyelin and polyamic acid mixture was calculated $2.67cm^2s^{-1}{\times}10^5$, $5.23cm^2s^{-1}{\times}10^6$ at 0.1 N and 0.2 N $KClO_4$ solutions, respectively.