• Journal of the Korean Electrochemical Society
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• v.5 no.3
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• pp.164-167
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• 2002

ABS/Polypyrrole composite film has been synthesized by means of electrochemical polymerization in order to enhance the oxidant stability by using ABS(Acrylonitrile-Butadiene-Strene) as a host-polymer. While the acetonitrile as a solvent swells the host-polymer ABS on Pt plate, and then the pyrrole in an electrolyte penetrates the Pre-coated ABS film during electrochemical Polymerization. Comparing with the sin91e-component Polypynole film, the resulting conducting ABS/PPy composite nim shows the good reliability for the uniform resistance and the enhancement of the oxidant stabilization.

• Korean Journal of Agricultural Science
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• v.11 no.2
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• pp.315-321
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• 1984

The electrochemical reduction of 0,0-dimethyl-0-(3-methyl-4 -nitrophenyl)-phosphorothioate ($Sumithion^{(R)}$) in acetonitrile solution has been studied by direct current (DC), differential pulse (DP) polarography and cyclic voltammetry methods. The irreversible electron-transfer chemical reaction (EC) mechanism of Sumithion proceeds by six electron-transfer to form radical and reduction of three-step which undergoes single bond of the phosphorus atom & phenoxy group by electron-transfer and protonation cleaved to give p-hydroxyamino-m-cresol and dimethylthiophosphonate as major product.

• Analytical Science and Technology
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• v.8 no.2
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• pp.171-179
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• 1995

This is an analytical study of germanium by adsorption stripping squarewave voltammetry. Tannic acid was used as a ligand. The accumulation potential was -0.2V, accumulation time was carried out for 60 second under constant stirring, followed by a 20 second quiescent period, and frequency was 10Hz. A hanging mercury drop electrode was used as a working electrode and acetate buffer solution, pH=4.5, as supporting electrolyte. The proper conditions of ligand for germanium analysis was established. The effect of metal ions(lead, cupper, silicon, tin, gallium) on germanium peak was also studied.

• Analytical Science and Technology
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• v.6 no.1
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• pp.83-92
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• 1993

The electrochemical behaviors of lanthanide ion(La and Nd) and lanthanide complexes with 2, 2, 6, 6-tetramethyl-3, 5-heptanedione(THD), sym-hydroxydibenzo-16-crown-5(HD16C5) and sym-dibenzo-16-crown-5-oxyacetic acid(D16C5A) ligands in acton solution have been investigated by the use of cyclic voltammetry and direct current polarography. The peak potential and peak current, their dependency on the concentration, temperature, the reversibility of the eleotrode reactions are described. The reduction of the lanthanide ions and complexes in 0.05 M TEAP proceeded one-electron step in first step and one two-electron step in second step. These reduction step was irreversible and the reduction current was diffusion controlled. Macrovcyclic crown ethers, sym-hydroxydibenzo-16-crown-5(HD16C5) and sym-dibenzo-16-crown-5-oxyacetic acid(D16C5A), were prepared from 1, 5-bis-(2-hydroxyphenoxy)-3-oxapentane with epichlorohydrin. The voltammetric behaviors of Ln(III)-HD16C5 and Ln-D16C5A complexes in aceton solution have been investigated by the voltammetric method. The composition and stability constants of lanthanide complexes were determined.

• Journal of the Korean Chemical Society
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• v.32 no.2
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• pp.130-134
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• 1988

Direct differential-pulse cathodic stripping voltammetry on mercury electrode (HMDE) provides a sensitive technique for low level cyanide measurement in distilled and sulfide free solution. Cyclic voltammetry revealed the forming and redissolution reactions were reversible at pH 7 in 0.1M KCl-0.01M phosphate supporting electrolyte. The analytical conditions have been optimized. With deposition time of 3 min at deposition potential 0.00V(vs. Ag/AgCl) in this medium of pH7, quite reproducible and linear calibration curve was obtained down to $3{\times}10^{-7}M$ (8ppb) $CN^-$ which was the detection limit.

• The Journal of Natural Sciences
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• v.11 no.1
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• pp.33-39
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• 1999

Electrochemical behaviors of $Sm^3+$-ARS complexes has been investigated by d.c.polarography, differential pulse polarography and cyclic voltammetry. $Sm^3+$forms 1 : 3 adsorptive complexes with ARS.The reduction potential of complex wave $(P_2)$ shifted more negatively than the ligand wave $(P_1)$. The linear calibration curves of decreasing $P_1$ and increasing $P_2$ is obtained when $Sm^3+$ concentration varies from TEX>$2{\times}10^{-6}$ M to $3.2{\times}10^{-5}$ M.

• 한국신재생에너지학회:학술대회논문집
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• 2010.11a
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• pp.198.1-198.1
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• 2010

고분자전해질 연료전지(PEMFC)의 핵심부품인 스택의 MEA는 전극과 멤브레인 전해질, GDL(Gas Diffusion Layer)로 구성되며, 전극은 Anoth극과 Cathod극으로 나뉘어 각각의 전극 특성에 적합한 전극촉매를 적용하게 된다. Anoth극과 Cathod극은 탄소 지지체 위에 원하는 사양의 희유금속이 도포되어 존재하는데 이들 희유금속은 그 희귀성으로 인해 사용 후 반드시 재사용되어야 한다. 사용된 전극에서의 희유금속 회수는 산침출, 불순물제거, 추출, 탈거 공정으로 이루어지며, 산침출 시 산화제로 사용된 NaOCl로 인한 침출용액 내의 Na+ 이온의 증가는 불순물제거 공정에 의해 반드시 제거되어야 한다. 따라서 본 연구에서는 CCG 방식으로 전극촉매를 GDL에 코팅한 MEA로부터 백금족 희유금속을 회수 시 MEA에 포함되어 있는 소량의 불순물을 제거하고자 한다.

• Resources Recycling
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• v.10 no.4
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• pp.18-23
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• 2001

Air pollutants, phenol was generated in case of thermal regeneration of used activated carbon loaded with phenol and because of this problem, removal process of phenol were studied. Electrolytic oxidation of samples, used S.company granular activated carbon (WS-GAC), used C.company granular activated carbon (WC-GAC) and used L.company granular activated carbon (WL-GAC) loaded with phenol carried out by potentiostatic method in this study. In case of experiment was to come into operation in condition of samples containing 100 mg/g phenol, supporting electrolyte was 1.0% sodium chloride solution, Ti-Ir (10$\times$10$\textrm{cm}^2$) electrode and electrode distance was 2 cm, current density was $1.25 A/dm^2$, Obtained from the results of electrolytic oxidation experiments were not detected residual phenol. And then we knew about reaction time of electrolytic oxidation, current density, concentration of supporting electrolyte and electrode and electrode distance were 60 minutes, 1.25 A/dm$^2$, 1.0%, 2 cm.

• Journal of the Korean Chemical Society
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• v.37 no.1
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• pp.83-91
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• 1993

The eletrochemical behavior of light lanthanide complexes has been investigated by several electrochemical techniques in alkaline solutions. The composition of the complexes was determined by spectrophotometric method to be 1 : 1 and reduction mechanism was two steps 1 electron transfer reaction. The half wave potential of first peak depended on pH and cathodic current showed remarkably adsorptive properties. The results of DC and CV investigation demonstrated the quise-reversible nature of the electron transfer. The anion radical formed after first one electron reduction process, dimerizes to form dimer. The apparent irreversible behavior of the second wave is a result of the existence of a fast protonation following the second electron transfer. An exhaustive electrolysis was carried out at controlled potential of -1.80 V, deep blue color of the solution became progressively weaker, and then the solution became colorless solution. The final product of an exhaustive electrolysis is electro-inactive. The appearance of four steps may be explained by the fact the reduction of Ln-OCP elucidated ECEC mechanism.

• Applied Chemistry for Engineering
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• v.10 no.7
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• pp.969-973
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• 1999

In this work, we studied the degree of hydrolysis of ion exchanger in $NH_4OH$ solution and sorption characteristics of $NH_3$ by potentiometric titration curves with using carboxylic acid ion exchanger Fiban K-4. We knew that the theoretical pH values agreed with the experimental pH values on the $NH_4OH$ concentrations in various concentrations of supporting electrolyte $(NH_4)_2SO_4$. The sorption values of $NH_3$ using the ion exchanger can be calculated from equivalent sorption curves for various pH. Also, the degree of hydrolysis increased with decreasing concentration of supporting electrolyte and pH. In order to obtain the mono ion form below 0.01 M as the decreasing concentration of supporting electrolyte, the pH values should be increased. From these results, therefore, the concentrations of supporting electrolyte and pH values were determined.