• 대한화학회지
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• 제15권6호
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• pp.347-352
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• 1971

The variations of the positive and negative electrode potentials, and of internal pressure were measured during the charge of the sealed type Ni-Cd cell. Both polarization characteristics of a paste type Cd-electrode as a gas diffusion electrode in 30% KOH solution and the effects of active carbon electrode as an oxygen consuming auxiliary electrode of the Ni-Cd cell on the charging characteristics of the cell were studied. Peak voltage at the end of charge of the cell is ascribed to the peak at the negative electrode potential, which is due to the concentration polarization by the lack of $Cd^{++}$ ion and oxygen concentration. And the recovery of the negative electrode potential is resulted from depolarization by the increasing diffusion limiting current density with the increasing oxygen pressure. The active carbon electrode was effective as an oxygen consuming auxiliary electrode. The internal pressure of the cell could be maintained below 200mmHg even at one hour rate charge and overcharge by the use of active carbon electrode as an auxiliary electrode.

• Journal of Electrochemical Science and Technology
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• 제9권2호
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• pp.109-117
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• 2018

A novel carbon paste electrode modified with $Cu-TiO_2$ nanocomposite, 2-(ferrocenylethynyl)fluoren-9-one (2FF) and ionic liquid (IL) (2FF/$Cu-TiO_2$/IL/CPE) was fabricated and employed to study the electrocatalytic oxidation of droxidopa, using cyclic voltammetry (CV), chronoamperometry (CHA) and differential pulse voltammetry (DPV) as diagnostic techniques. It has been found that the oxidation of droxidopa at the surface of modified electrode occurs at a potential of about 295 mV less positive than that of an unmodified CPE. DPV exhibits a linear dynamic range from $5.0{\times}10^{-8}$ to $4.0{\times}10^{-4}M$ and a detection limit of 30.0 nM for droxidopa. Finally this modified electrode was used for simultaneous determination of droxidopa and tryptophan. Also the 2FF/$Cu-TiO_2$/IL/CPE shows excellent ability to determination of droxidopa and tryptophan in real samples.

• 한국환경과학회지
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• 제21권11호
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• pp.1333-1338
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• 2012

In order to measure the minute amount of Cu(II) in our environment, cyclic voltammetry (CV) and square-wave stripping voltammetry (SWSV) were performed for a trace copper assay using bismuth immobilized on a carbon nanotube paste electrode. An analytical working range of 30 to $240{\mu}g/L$ Cu(II) was obtained for CV and SWSV. The SWSV precision obtained was 0.47 % (n = 15) RSD in $30.0{\mu}g/L$ Cu(II). The detection limit obtained was 3.1 ng/L Cu(II) using SWSV, while the CV yielded the nano-range detection limit through the pre-concentration step. By using this research method, Cu(II) value could be determined in the urine of human sample and in the brain of fish sample. This research can be effectively applied to other cases of measuring minute amount of Cu(II) in living organisms.

• Bulletin of the Korean Chemical Society
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• 제28권4호
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• pp.543-546
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• 2007

Herein, a new electrochemical method was described for the determination of ciprofloxacin based on the enhancement effect of an anionic surfactant: sodium dodecyl benzene sulfonate (SDBS). In pH 4.0 phosphate buffer and in the presence of 1.0 × 10-4 mol/L SDBS, ciprofloxacin yields a well-defined and sensitive oxidation peak at the carbon paste electrode (CPE). Compared with that in the absence of SDBS, the oxidation peak current of ciprofloxacin remarkably increases in the presence of SDBS. The experimental parameters, such as supporting electrolyte, concentration of SDBS, and accumulation time, were optimized for ciprofloxacin determination. The oxidation peak current is proportional to the concentration of ciprofloxacin over the range from 8.0 × 10-8 to 5.0 × 10-6 mol L-1. The detection limit is 2.0 × 10-8 mol L-1 after 2 min of accumulation. This new voltammetric method was successfully used to detect ciprofloxacin in drugs.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제54권4호
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• pp.139-143
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• 2005

For application of carbon nano-tube (CNT) as a counter electrode materials of dye-sensitized solar cell (DSSC), the electrochemical behavior of CNT electrode was studied, employing cyclic-voltammetry (C-V) and impedance spectroscopy. Fabrication of CNT-paste and formation of CNT-counter electrode for characteristic measurement have been carried out using ball-milling and doctor blade process, respectively. Unit cell for measurements was assembled using Pt electrode, CNT electrode, and iodine-embedded electrolyte. Field emission-scanning electron microscopy (FE-SEM) was used for structural investigation of CNT powder and electrode. Sheet resistance of electrode was measured with 4-point probe method. Electrochemical properties of electrode, C-V and impedance spectrum, were studied, employing potentiogalvanostat (EG&G 273A) and lock in amplifier (EG&G 5210). As a results, the sheet resistance of CNT electrode is almost similar to that of F-doped SnO2 (FTO) coated glass substrate as approximately 10 ohm/sq. From C-V and impedance spectroscopy measurements, it was found that CNT electrode has high reaction rate and low interface reaction resistance between CNT surface and electrolyte. These results provides that CNT electrode were superior to that of conventional Pt electrode. Particularly, the reaction rate in the CNT electrode is about thrice high than Pt electrode. Therefore. CNT electrode is to be good candidate material for counter electrode in DSSC.

• 분석과학
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• 제24권2호
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• pp.113-118
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• 2011

톨루엔에 녹인 부틸고무 용액을 탄소가루의 결합재로 사용하였을 때, 탄소반죽은 용매 증발 후 기계적 경도를 보였다. 고무 용액의 이런 성질을 이용하여 닭의 간조직이 혼입된 새로운 과산화수소 정량 효소전극을 제조하였다. 그것이 전기화학적으로 정량적 행동을 보이는지 확인하기 위하여 그것의 전기화학적 파라메타 즉 이중층의 대칭인자, 교환전류밀도, 축전용량, Michaelis 상수 및 시간상수 등을 도출하였다. 실험 결과는 부틸고무 용액이 탄소가루의 결합재로 활용될 수 있음을 보여 주었다.

• 전기화학회지
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• 제13권1호
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• pp.63-69
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• 2010

플루오로퀴놀론 계 항생제들의 전기화학적 거동을 카본 페이스트 전극 (carbon paste electrode ; CPE)을 사용하여 순환 전압전류법 (cyclic voltammetry)과 네모파 흡착 벗김 전압전류법 (square wave adsorptive stripping voltammetry)으로 연구하였다. Enrofloxacin (ENR), Norfloxacin (NOR), Ciprofloxacin (CIP), Ofloxacin (OFL), Levofloxacin (LEV) 등 5가지 플루오로퀴놀론 계 항생제에 대한 전기화학적 분석을 수행하였다. pH 4.5인 아세트산 완충 용액 (acetate buffer) 에서 플루오로퀴놀론 계 항생제의 산화 전위는 Ag/AgCl 기준 전극에 대하여 각각 ENR : 0.952V, NOR : 1.052 V, CIP : 1.055 V, OFL : 0.983 V, LEV : 0.990 V 의 값을 나타내었으며, 네모파 흡착 벗김 전압전류법에 의한 산화 전류는 $0.2\;{\mu}M$에서 $1\;{\mu}M$ 사이의 농도영역에서 각 항생제의 농도와 선형을 나타내었다.

• 청정기술
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• 제19권4호
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• pp.410-415
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• 2013

폴리이미드(polyimide) 필름 위에 은(Ag) 나노 페이스트(paste)가 인쇄된 집전체 및 활성탄소(activated carbon)를 이용하여 제조한 페이스트와 5% potassium polyacrylate (PAAK) 겔(gel) 전해질을 이용하여 슈퍼캐패시터(supercapacitor) 반쪽전지(half cell)를 제작하였다. 집전체 및 전극은 스크린 인쇄를 이용하여 제작하였으며 인쇄된 집전체의 두께는 $7.3{\mu}m$이고 면저항은 $5{\sim}7m{\Omega}/square$이다. 전극 페이스트는 비표면적 $1,968m^2/g$인 활성탄소이고 도전재는 카본 블랙(carbon black)을 사용하였으며 바인더로는 poly (4-vinylphenol)를 7:1:3 비율로 혼합하고 2-(2-buthoxyethoxy) 에틸아세테이트(BCA)를 주 용매로 사용하여 제조하였다. 전기화학적 분석을 위해 순환-전압 전류법(cyclic voltammetry)을 이용하여 전기화학적 특성과 안정도를 평가하였으며 순환-전압전류법 측정을 위한 인가 전압의 범위는 -0.5 V~0.5 V이고 주사속도(scan rate)의 범위는 10~500 mV/s로 하였다. 제작된 슈퍼캐패시터 반쪽전지의 비축전 용량은 주사속도가 10 mV/s, 500 mV/s일 때 각각 44.04 F/g, 8.62 F/g이었다.

• 폴리머
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• 제27권4호
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• pp.275-284
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• 2003

접착성이 없는 고밀도 폴리에틸렌 (HDPE)과 나노입자 카본블랙 복합체를 대상으로 전극과의 계면 접착 향상과 고분자 가교 특성에 따른 양온도 계수 (PTC) 특성을 연구하였다. 은페이스트를 전극으로 사용하였을 때에는, 전극과 HDPE의 접착 계면 저항으로 인하여 카본함량이 45 wt% 이상에서 1 $\Omega$ 이었으나, 덴드라이트 (dendrite)된 구리 전극의 경우 HDPE와 전극간의 넓은 면적 접촉에 의한 계면 저항이 0.2 $\Omega$ 이하였다. HDPE와 은페이스트의 계면 저항의 증가로 인하여 구리 박막을 사용하였을 때보다 전체적으로 저항이 높게 나타났다. HDPE와 나노입자 카본블랙 복합체는 온도가 증가하여 HDPE의 비캣연화온도까지는 저항이 일정하게 유지하다가, HDPE의 연화점에서 증가하기 시작하여 용융점에서 극대 값을 나타내는 전형적인 PTC특성을 보여주었다. 일반적으로 HDPE의 용융점을 넘어서면 음온도 계수 (NTC) 현상이 나타나는데, 가교결합을 시킨 HDPE의 경우는, 용융점 이상에서 NTC 현상이 나타나지 않고 저항이 일정하게 유지되거나 증가하는 경향이 나타났다. 구리 (copper) 전극과 고분자와의 계면 접촉 면적을 증가시키기 위하여 크롬 (chromium)을 덴드라이트시킨 전극을 사용하여 계면 접촉 저항을 감소시켰다.

• 한국전기전자재료학회논문지
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• 제20권5호
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• pp.456-461
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• 2007

In this study, a surface treatment method using accelerated Ar ions was experimented for exposing the carbon nanotubes (CNT) from the screen-printed CNT paste. After making a cathode electrode on the glass substrate, photo sensitive CNT paste was screen-printed, and then back-side was exposed by UV light. Then, the exposed CNT paste was selectively remained by development. After post-baking, the remained CNT paste was bombarded by accelerated Ar ions for removing some binders and exposing only CNTs. As results, the field emission characteristics were strongly depended on the accelerating energy, bombardment time, and the power of RF plasma ion source. When Ar ions accelerated with 100 eV energy from the 100 W RF plasma source are bombarded on the CNT paste surface for 10 min, the emission level and the uniformity were best.