• Title/Summary/Keyword: Cyclic voltammogram

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Conducting Polypyrrole Doped with Hexacyanoferrate Anions: an Electrochemical and Spectroscopic Study

  • Han Junghee;Lee Seungjun;Paik Woon-kie
    • 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.

The Preparation Characteristic of Dimercaptan-Polyphenylenediamine Cathodes for Lithium Battery (리튬전지용 Dimercaptan-Polyphenylenediamine 정극의 제막특성)

  • Park, Soo-Gil;Lee, Ju-Seong
    • Applied Chemistry for Engineering
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    • v.8 no.1
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    • pp.114-121
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    • 1997
  • The positive active material for polymer film-battery was prepared by using polyphenlenediamine(PPD) synthesized in our lab. and 2,5-dimercapto-1,3,4-thiadiazole(DMcT) with various mixture ratio. The transference measurement of surface morphology and thermal stability of the prepared composite film was carried out by using SEM and TGA, respectively. Electrochemical property and electrical conductivity of the composite film were also measured by using cyclic voltammetry and four-probe method in dry box, respectively. The thermal stability of prepared composite film was up to $200^{\circ}C$. The electrical conductivity of the composite film increased and showed the highest value(about 3 S/cm) when doped at 0.4% $LiCIO_4$ solution. And we could confirm that DMcT was effective on reactivation of PPD through cyclic voltammogram.

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A Study on the Electrochemical Properties of Langmuir-Blodgett Nano-film Mixed with Polyimide and Phospholipid (폴리이미드와 인지질 혼합물의 나노 Langmuir-Blodgett막의 전기화학적 특성에 관한 연구)

  • Park, Keun-Ho
    • 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.

A Study on the Electrochemical Properties of Langmuir-Blodgett Monolayer Film for the Changes of Concentration with Polyamic Acid and Sphingomyelin Mixture (Sphingomyelin과 Polyamic Acid의 농도 변화에 대한 단분자 LB막의 전기화학적 특성에 관한 연구)

  • Park, Keun-Ho
    • Journal of the Korean Applied Science and Technology
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    • v.30 no.4
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    • pp.754-760
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    • 2013
  • We investigated an electrochemical properties for Langmuir-Blodgett (LB) monolayer films of sphingomyelin(SP) and polyamic acid(PAA) mixture(1:1, 2:1 and 3:1 molar ratio). 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 0.1N $KClO_4$ solution. As a result, LB monolayer films of SP and PAA mixture was appeared on irreversible process caused by the reduction current from the cyclic voltammogram. Diffusion coefficient(D) in the SP and PAA mixture was calculated $2.670{\times}10^{-5}$, $3.562{\times}10^{-5}$ and $1.005{\times}10^{-5}cm^2s^{-1}$ at 1:1, 2:1 and 3:1 molar ratio, respectively.

Electrochemical Properties of Organic Ultra Thin Films of Fatty Acid and Phospholipid Mixture (지방산과 인지질 혼합 유가초박막의 전기화학적 특성)

  • Park, Keun-Ho;Choi, Sung-Hyun;Son, Tae-Churl;Song, Ju-Yeong
    • Journal of the Korean Applied Science and Technology
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    • v.23 no.2
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    • pp.137-146
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    • 2006
  • We investigated the electrochemical properties for Langmuir-Blodgett (LB) films mixed with fatty acid (8A5H) and phospholipid (DLPE, DMPC, and DPPA). LB films of 8A5H monolayer and 8A5H-phospholipid mixture were deposited using the Langmuir-Blodgett method on the indium tin oxide(ITO) glass. The electrochemical properties measured using cyclic voltammetry with three-electrode system, an Ag/AgCl reference electrode, a platinum wire counter electrode and LB film-coated ITO working electrode at various concentrations(0.1, 0.5, and 1.0 mol/L) of $NaClO_4$ solution. A measuring range was reduced from initial potential to -1350 mV, continuously oxidized to 1650 mV and measured to the initial point. The scan rate was 50, 100, 150 and 200 mV/s, respectively. As a result, LB films of fatty acid and phospholipid (8A5H/DLPE and DPPA) appeared irreversible process were caused by only the reduction current from the cyclic voltammogram and LB film of 8A5H-DMPC mixture was found to be caused by a reversible oxidation-reduction process.

A Study on the Stability of Ultra-Thin Film Mixed with Stearic Acid and Phospholipid (스테아르산과 인지질 혼합물의 농도변화에 대한 유기초박막의 안정성에 관한 연구)

  • Park, Keun-Ho
    • Journal of the Korean Applied Science and Technology
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    • v.32 no.4
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    • pp.789-794
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    • 2015
  • In this study, we investigated the stability with respect to the Langmuir-Blodgett(LB) monolayer films of stearic acid and phospholipid(L-${\alpha}$-dimyristoylphosphatidyl choline, DMPC) mixture. LB films of stearic acid and DMPC monolayer were deposited by the LB method on the indium tin oxide(ITO) glass. The electrochemical properties measured by cyclic voltammetry with three-electrode system in $0.05N\;NaClO_4$ solution, -0.3 V initial, 1650 mV switching potential and -1350 mV final potential. As a result, monolayer LB films of stearic acid and phospholipid mixture was appeared on irreversible process caused by the oxidation current from the cyclic voltammogram. Diffusion coefficient (D) of stearic acid and DMPC mixture(molar ratio 1:1, 1:2, 1:3) was calculated $1.4{\times}10^{-3}$, $1.7{\times}10^{-3}$ and $1.6{\times}10^{-3}(cm^2/s)$ in $0.05N\;NaClO_4$ solution, respectively.

Electrochemistry Characterization of Metal Using Monoethanolamine as Corrosion Inhibitor (부식억제제로 모노에탄올아민을 사용한 금속의 전기화학적 특성)

  • Park, Keun-Ho
    • Journal of the Korean Applied Science and Technology
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    • v.29 no.1
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    • pp.88-94
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    • 2012
  • In this study, the current-voltage curves for metals were measured using cyclic voltammetry. The relationship between the electrochemical properties and surface states of metals were investigated by Scanning Electron Microscope (SEM). In cyclic voltammetry, we used a 3-electrode system for the electrochemical measurements. The measurement was conducted at the condition that consists of the first reduction from the initial potential to -1350 mV, continuous oxidation to 1650 mV, and last reduction to the initial potential. The scan rates were 50, 100, 150 and 250 mV/s. The results show the C-V characteristics of metals to be for an irreversible process, which was caused by the oxidation current from cyclic voltammogram, when monoethanolamine (MEA) was used as a corrosion inhibitor. When we used MEA as a corrosion inhibitor, the diffusion coefficient was decreased as the concentration of electrolyte was increased. In the SEM images of copper, we observed an increase of surface corrosion at the increased electrolyte concentration. Addition of $1.0{\times}10^{-3}M$ corrosion inhibitor MEA reduced the effect of corrosion prevention due to the relatively large diffusion coefficient at the electrolyte concentration of 0.1N.

A Study on the Electrochemical Properties of Langmuir-Blodgett Monolayer Film Mixed with Polyamic Acid and Sphingomyelin (인지질(Sphingomyelin)과 Polyamic Acid 혼합물의 단분자 LB막의 전기화학적 특성에 관한 연구)

  • Park, Keun-Ho
    • 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.

Electrochemical Properties of Langmuir-Blodgett(LB) Films of Fatty Acid Containing Azobenzene and $L-{\alpha}-dimyristoylphosphatidylcholine$ Mixture (아조벤젠기를 가진 지방산과 $L-{\alpha}-dimyristoylphosphatidylcholine$ 혼합 LB막의 전기화학적 특성)

  • Park, Keun-Ho;Choi, Sung-Hyun;Song, Ju-Yeong
    • Journal of the Korean Applied Science and Technology
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    • v.22 no.4
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    • pp.315-322
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    • 2005
  • We investigated the electrochemical properties for Langmuir-Blodgett (LB) films mixed with 4-octyl-4'-(5-carboxylpentamethyleneoxy)azobenzene (denoted as 8A5H) and $phospholipid(L-{\alpha}-dimyristoylphosphatidylcholine$, denoted as DMPC). LB films of 8A5H monolayer and 8A5H-DMPC were deposited by using the Langmuir-Blodgett method on the indium tin oxide(ITO) glass. The electrochemical properties measured by using cyclic voltammetry with a three_electrode system, an Ag/AgCl reference electrode, a platinum wire counter electrode and LB film-coated ITO working electrode at various concentrations(0.1, 0.5, and 1.0mol/L) of $NaClO_4$ solution. A measuring range was reduced from initial potential to -1350mV, continuously oxidized to 1650mV and measured to the initial point. The scan rates were 50, 100, 150 and 200mV/s, respectively. As a result, LB films of 8A5H monolayer appeared irreversible process caused by only the oxidation current from the cyclic voltammogram and LB films of 8A5H-DMPC mixture were found to be caused by a reversible oxidation-reduction process.

Electrochemical Characterization of Stainless Steel in Ethanolamine Solution Containing an Alkyl Group using Cyclic Voltammetry (순환전압전류법에 의한 알킬기를 함유한 에탄올아민용액에서 스테인리스의 전기화학적 특성)

  • Park, Keun-Ho
    • Journal of the Korean Applied Science and Technology
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    • v.31 no.1
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    • pp.66-73
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    • 2014
  • In this work, the current-voltage curves for stainless steel in the ethanolamine solution containing alkyl group were measured using the conventional three electrodes of cyclic voltammetry. Stainless steel as working electrode, Ag/AgCl electrode as reference electrode and Pt wire as counter electrode were used respectively. As a result, the C-V characteristics of stainless steel were to be for an irreversible process due to the oxidation current from cyclic voltammogram, using N-ethylethanolamine and N,N-dimethylethanolamine solutions. Effective diffusivity of corrosion inhibitors was decreased with increasing concentration. It was found from SEM images of the metal that the electrolyte (specific name ?)(0.5 N) as corrosion inhibitor was added into a N, N-diethylethanolamine solution ($1.0{\times}10^{-3}M$) containing copper and nickel, the corrosion inhibiting effect was enhanced.