• 한국의학물리학회지:의학물리
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• 제15권2호
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• pp.59-62
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• 2004

본 논문에서는 마이크로필름과 탄소막 전극을 이용하여 개발한 소형 방사선측정기의 특성을 평가하였다. 전극은 5 mm 직경의 고전압전극, 3.3 mm 직경의 수집전극, 그리고 넓이가 0.7 mm인 보호전극으로 구성되었으며, 이온수집 공동의 부피는 0.016 ㎤이었다. 6 MV X-선을 이용하여 제작된 측정기에 대한 전기적 특성을 조사하였는데, 누설전류는 0.1 pA, 재현 오차가 0.1% 이하, 선량률 효과는 1.5% 이하, 분극효과는 2.4% 이하로 나타났다. 개발된 측정기의 전기적 특성은 양호한 것으로 평가되며, 추후 깊이선량률, 빔측면도와 같은 선량분포에 대한 특성의 평가가 요구된다.

• 공업화학
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• 제32권4호
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• pp.403-408
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• 2021

본 논문에서는 얇고 유연한 평면 슈퍼 커패시터(PSC)를 스크린 인쇄된 탄소 전극에 폴리아닐린(PANI)을 코팅하여 제작하였습니다. 스크린 프린팅 방법을 사용하여 유연한 폴리에틸렌 테레프탈레이트에 탄소 잉크를 코팅한 후 희석 중합 법을 사용하여 탄소 표면에 PANI 박막을 코팅하였습니다. 서로 맞물린 구조의 얇은 유연한 PANI 전극을 폴리머겔 전해질로 조립하여 평면 모양의 슈퍼 커패시터(PSC) 장치를 만들었습니다. 상기 제조된 PANI/PSC는 매우 얇고 유연 하였으며, 10 mV/s에서 409 µF/cm²의 높은 면적 정전용량을 나타내었습니다. 이 값은 500 mV/s에서 원래 값의 46%로 유지되었습니다. 유연한 PANI/PSC는 180°의 구부러진 상태와 100번째의 반복적인 피로도 테스트에서도 82%의 높은 정전 용량 유지를 보여주었습니다.

• Bulletin of the Korean Chemical Society
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• 제33권8호
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• pp.2529-2534
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• 2012

Poly(3,4-ethylenedioxythiophene) coated Manganese Dioxide (PEDOT/$MnO_2$) composite electrode was fabricated by simply immersing the $MnO_2$ electrode in an acidic aqueous solution containing 3,4-ethylenedioxythiophene (EDOT) monomers. Analysis of open-circuit potential of the $MnO_2$ electrode in the solution indicates the reduction of outer surface of $MnO_2$ to dissolved $Mn^{2+}$ ions and simultaneously oxidation of EDOT monomer to PEDOT on the $MnO_2$ surface to form a PEDOT shell via a galvanic displacement reaction. Analysis of cyclic voltammograms and specific capacitance of the PEDOT/$MnO_2$, conductive carbon added $MnO_2$ and conductive carbon added PEDOT/$MnO_2$ electrodes suggests that the conductive carbon acted mainly to provide a continuous conducting path in the electrode to improve the rate capability and the PEDOT layer on $MnO_2$ acts to increase the active reaction site of $MnO_2$.

• Bulletin of the Korean Chemical Society
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• 제24권7호
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• pp.948-952
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• 2003

New approach for the determination of Ag(I) ion was performed by using a carbon paste electrode (CPE) containing N,N'-Diphenyl oxamide (DPO) with anodic stripping voltammetry. The CMEs have been prepared by making carbon paste mixtures containing an appropriate amount of DPO salt coated onto graphite particles to analyze trace metal ions via complexation followed by stripping voltammetry. Various experimental parameters affecting the response, such as pH, deposition time, temperature, and electrode composition, were carefully optimized. Using differential pulse anodic stripping voltammetry, the logarithmic linear response range for the Ag(I) ion was 1.0 × $10^{-7}$ - 5.0 × $10^{-9}$ M at the deposition time of 10 min, with the detection limit was 7.0 × $10^{-10}$ M. The detection limit adopted from anodic stripping differential pulse voltammetry was 7.0 × $10^{-10}$ M for silver and the relative standard deviation was ± 3.2% at a 5.0 × $10^{-8}$ M of Ag(I) ion (n = 7). The proposed electrode shows a very good selectivity for Ag(I) in a standard solution containing several metals at optimized conditions.

• 전기화학회지
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• 제18권2호
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• pp.81-85
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• 2015

A method for degradation of the perchlorate anion ($ClO{_4}^-$) has been studied using electrochemically generated zero-valent iron (ZVI) deposited on a porous carbon electrode. The first strategy of this study is to produce the ZVI via the electrochemical reduction of iron (II) on a porous carbon electrode coated with a conducting polymer, instead of employing expensive $NaBH_4$. The present method produced well distributed ZVI on conducting polymer (polypyrrole thin film) and increased surface area. ZVI surface can be regenerated easily for successive reduction. The second strategy is to apply a mild reducing condition (-0.3 V) to enhance the efficiency of the degradation of perchlorate with ZVI without the evolution of hydrogen. The electrochemically generated ZVI nanoparticles may offer an alternative means for the complete destruction perchlorate without evolution of hydrogen in water with high efficiency and at low cost.

• 한국전기전자재료학회논문지
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• 제27권12호
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• pp.866-870
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• 2014

In solid oxide fuel cell system, yttria-stabilized zirconia is generally adopted as the electrolyte, which has high strength and superior oxygen ion conductivity, and the air electrode and the fuel electrode are attached to this. Recently, new structure of 'layered planar SOFC module' was suggested to solve the reliability problem due to the high temperature stability of a sealing agent and a binding material. In this study to materialize the air electrode in a layered planar SOFC module, the LSM ink was coated to form homogeneous electrode in the channel after the ink preparation. As the porosity control agent, PMMA or active carbon powder was adopted with use of a commercial dispersant in ethanol. The optimal amounts of both the porosity control agents and the dispersant were determined. Four (4) vol% of the dispersant for the LSM-PMMA case and 15 vol% for LSM-carbon powder showed the lowest viscosities respectively to indicate the best dispersed states of the slurries. With PMMA and carbon powder, sintered LSM ink shows the relatively homogeneous distributions of pores and with increases of the agents, the porosities increased in both cases. From this, it can be thought that the amount of the PMMA or carbon powder could be used to control the porosity of the LSM ink.

• 분석과학
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• 제8권4호
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• pp.611-615
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• 1995

The design of appropriate chemically modified electrodes should allow development of new voltammetric measurement schemes with enhanced selectivity and sensitivity. Microorganism like algae has high ability to trap toxic and heavy metal ions and different affinities for metal ions. A copper(II) ion-selective carbon paste electrode was constructed by incorporating alga Anabaena into a conventional carbon paste mixture, and then the film of 10% Nafion was coated to avoid the swelling of the electrode surface. Copper ion could be deposited at the 25% algamodified electrode for 15 min without the applied potential while stirring the solution by only immersing the electrode in a buffer (pH 4.0) cot1taining copper(II). Temperature was controlled at $35^{\circ}C$. After preconcentration was carried out the electrode was transferred to a 0.1 M potassium chloride solution and was reduced at -0.6 volt at $25^{\circ}C$. The differential pulse anodic stripping voltammetry was employed. A well-defined oxidation peak could be obtained at -0.1 volt (vs SCE). In five deposition / measurement / regeneration cycles, the responses were reproducible and relative standard deviations were 3.3% for $8.0{\times}10^{-4}M$ copper(II). Calibration curve for copper was linear over the range from $2.0{\times}10^{-4}M$ to $1.0{\times}10^{-3}M$. The detection limit was $7.5{\times}10^{-5}M$. Studies of the effect of diverse ions showed that the coexisting metal ions had little or no effect for the determination of copper. But anions such as cyanide. oxalate and EDTA seriously interfered.

• 한국대기환경학회지
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• 제29권6호
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• pp.830-837
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• 2013

The purposes of this research are to know the dust removal efficiency according to the changes of gab between positive and negative plates in dust removal chamber. The experiments for dust removal efficiencies were conducted with changing the electrode-plate gab from 2 cm to 1 cm while the electric pressure, influent flow, and linear velocity were kept 5 kV, 80 L/min, and 6 cm/sec, respectively. From the experimental results of the electrode-plate gab of 2 cm, dust removal efficiencies were decreased to as low as about 50%. Attached dust on the surface of electrodes was released due to a reverse electric charge of dust. From the experimental results of the electrode-plate gab of 1 cm, dust removal efficiencies were increased to as high as about 80% due to the dust attachment velocity to the electrodes to be far more fast than influent linear velocity. Finally, to protect a attached dust from occurring a reverse electric charge it is needed to install the non-conductor between positive and negative electrodes and also to remove air humidity.

• 한국환경보건학회지
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• 제29권2호
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• pp.62-68
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• 2003

Differential pulse voltammetry (DPV) using nafion-coated glassy carbon electrodes modified with Tetren(tetraethylene pentamine)-glycerol showed sensitivity for determining lead (II) at low concentration. The Lead (II) was accumulated on the electrode surface by the formation of the complex in an open circuit, and the resulting surface was characterized by medium exchange, electrochemical reduction, and differential pulse voltammetry. Various experimental parameters, such as the composition of modifier, preconcentration time, pH of electrolyte (0.1 M acetate buffer), and parameters of differential pulse voltammetry, were optimized. The initial potential was applied for 50 s, the electrode was scanned from -0.9 to -0.3 V, and the anodic peak current was measured at -0.604 V $\pm$ 0.015 V (vs. Ag/AgCl). The calibration plot was obtained in the range 1.0$\times$10$^{-8}$ M~l.0$\times$10$^{-6}$ M with pH 4.5 buffer solution. The detection limit (3$\sigma$) it as low as 5.0$\times$ 10$^{-9}$ M. This method is applied to the determination of lead(II) in a certified reference material and the result agrees satisfactorily with the certified value.

• 멤브레인
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• 제24권4호
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• pp.332-339
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• 2014

본 연구에서는 축전식 탈이온 공정(capacitive deionization, CDI)의 성능을 개선하기 위해 poly(2,6-dimethyl-1,4-phenylene oxide) (PPO)를 기저물질로 이용하여 코팅이 가능한 음이온교환 이오노머(quaternized PPO, QPPO) 용액을 제조하였다. 제조된 QPPO는 상용 음이온교환막(AMX, Astom Corp., Japan) 대비 우수한 이온전도도 특성을 나타내었으며 전기화학적 특성 또한 동등 수준임을 확인할 수 있었다. 다공성 탄소 전극에 이오노머 용액을 코팅하여 CDI 성능평가를 수행하였으며 그 결과 약 94.9%의 높은 염 제거 효율을 나타내었다. 기존의 CDI와 상용 음이온교환막을 결합한 membrane CDI (MCDI), QPPO가 코팅된 전극을 사용한 coated CDI (CCDI)의 탈염 성능을 비교한 결과 QPPO의 높은 이온선택성 및 낮은 이온 전달저항으로 CCDI가 기존의 CDI에 비해 52.1%, MCDI에 비해 18.3% 향상된 높은 염 제거 성능을 나타냄을 확인하였다.