• Title/Summary/Keyword: platinum electrode

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Fabrication of Electro-active Polymer Actuator Based on Transparent Graphene Electrode

  • Park, Yunjae;Choi, Hyonkwang;Im, Kihong;Kim, Seonpil;Jeon, Minhyon
    • Proceedings of the Korean Vacuum Society Conference
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    • 2014.02a
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    • pp.386.1-386.1
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    • 2014
  • The ionic polymer-metal composite (IPMC), a type of electro-active polymer material, has received enormous interest in various fields such as robotics, medical sensors, artificial muscles because it has many advantages of flexibility, light weight, high displacement, and low voltage activation, compare to traditional mechanical actuators. Mostly noble metal materials such as gold or platinum were used to form the electrode of an IPMC by using electroless plating process. Furthermore, carbon-based materials, which are carbon nanotube (CNT) and reduced graphene-CNT composite, were used to alter the electrode of IPMC. To form the electrode of IPMC, we employ the synthesized graphene on copper foil by chemical vapor deposition method and use the transfer process by using a support of PET/silicone film. The properties of graphene were evaluated by Raman spectroscopy, UV/Vis spectroscopy, and 4-point probe. The structure and surface of IPMC were analyzed via field emission scanning electron microscope. The fabricated IPMC performance such as displacement and operating frequency was measured in underwater.

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Electrochemical Properties of Langmuir-Blodgett(LB) Monolayer Films of Alkyl Bromides Mixture (브롬화 알킬혼합물 단분자 LB막의 전기화학적 특징)

  • Son, Tae-Chul;Kim, Duck-Sool;Park, Keun-Ho
    • Journal of the Korean Applied Science and Technology
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    • v.27 no.2
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    • pp.202-207
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    • 2010
  • We investigated the electrochemical properties for Langmuir-Blodgett(LB) films mixed with l-bromotetradecane(Cl4), l-bromohexadecane(Cl6), and l-bromooctadecane(Cl8). The alkyl bromides mixture was deposited by using the Langmuir-Blodgett method on the 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(0.5, 1.0, 1.5 and 2.0 N) of $NaClO_4$ solution. A measuring range was reduced from initial potential to -1350 m V, continuously oxidized to 1650 mV. The scan rate was 100 mV/s. As a result, LB films of Cl4, Cl6, and Cl8 mixture monolayers appeared irreversible process caused by only the oxidation current from the cyclic voltammogram. The diffusivity(D) effect of LB films decreased with increasing of alkyl bromides amount.

Performance Assessment of Electrolysis Using Copper and Catalyzed Electrodes for Enhanced Nutrient Removal from Wastewater

  • Kim, Woo-Yeol;Son, Dong-Jin;Yun, Chan-Young;Kim, Dae-Gun;Chang, Duk;Sunwoo, Young;Hong, Ki-Ho
    • Journal of Electrochemical Science and Technology
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    • v.8 no.2
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    • pp.124-132
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    • 2017
  • The performance of electrolytic processes using copper and catalyzed electrodes for enhanced nutrient removal with various catalyzers and combinations of electrodes was evaluated. The catalyzed electrodes removed more ammonia nitrogen than the copper electrode, but higher ammonia removal was achieved using a Pt/Ti anode. On the other hand, electrolysis using the Pt/Cu anode consumed less energy and cost less. During electroreduction, nitrate was better removed by a pair of copper electrodes than by the catalyzed electrodes. During electrolysis of synthetic wastewater, ammonia removal not only increased owing to direct oxidation at the anode, but was also influenced by indirect oxidation at the cathode. Platinum-coated copper and titanium cathodes actively produced oxidizers and thus removed more ammonia than a pure metal cathode. Although phosphorus was removable irrespective of the type of catalyzer, electrocoagulation using the copper electrode achieved complete removal of phosphorus in a period of less than 10 min.

A Study on the Oxidation-reduction Reaction of Organic Thin Films (유기초박막의 산화-환원 반응에 관한 연구)

  • Park Keun-Ho;Song Ju-Yeong
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.19 no.8
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    • pp.724-731
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    • 2006
  • We investigated the electrochemical properties for Langmuir-Blodgett (LB) films mixed with 4-octyl-4'-(5-carboxylpentamethyleneoxy)azobenzene (denoted as 8A5H) and phospholipid(L-a-dimyristoylphosphatidylcholine, denoted as DMPC and L-a-dilauroylphosphayidylcholine, denoted as DLPC). The LB films of 8A5H, 8A5H-DMPC and 8A5H-DLPC mixture monolayers were deposited by using the LB 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 1.0 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 rates were 50, 100, 150 and 200 mV/s, respectively. As a result, LB films of 8A5H and 8A5H-DLPC mixture monolayers appeared irreversible process caused by only the oxidation current from the cyclic voltammogram and LB films of 8A5H-DMPC monolayer mixture was found to be caused by a reversible oxidation-reduction process.

Gate Electrode Dependence of MFSFETs using $LiNbO_3$ Thin Film ($LiNbO_3$ 박막을 이용한 MFSFET의 게이트 전극 의존성)

  • 정순원;김용성;김채규;이남열;김광호
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1999.11a
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    • pp.25-28
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    • 1999
  • Metal ferroelectric semiconductor Field Effect- Transistors(MFSFET) with various gate electrodes, that are aluminum, platinum and poly -Si, using LiNbO$_3$/Si(100) structures were fabricated and the properties of the FETs have been discussed. The drain current of the state of FET with Pt electrode was more than 3 orders of magnitude larger than the state current at the same gate voltage of 1.5 V, 7.rich means the memory operation of the MFSFET. A write voltage as low as about $\pm$4 V, which is applicable to low power integrated circuits, was used for polarization reversal. The retention properties of the FET using Al electrode were quite good up to about 10$^3$s and using Pt electrode remained almost the same value of its initial value over 2 days at room temperature.

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A Study on the Electronic Properties of LB Thin Films (LB박막의 전자이동 특성에 관한 연구)

  • Song, Jin-Won;Choi, Young-Il;Lee, Kyung-Sup
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2002.08a
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    • pp.101-104
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    • 2002
  • Abstract We give pressure stimulation into organic thin films and then manufacture a device under the accumulation condition that the state surface pressure is 10[mN/m]. In processing of a device manufacture, we can see the process is good from the change of a surface pressure for organic thin films and transfer ratio of area per molecule. The structure of manufactured device is Au/Poly-${\gamma}$ Benzyl $_D$-Glutamate/Al; the number of accumulated layers is 1, 3, 5 and 7. Also, we then examined of the MIM device by means of I-V. The I-V characteristic of the device is measured from 0 to +2[V]. We determined electrochemical measurement by using cyclic voltammetry with a three-electrode system. LB film accumulated by monolayer on an ITO. In the cyclicvoltammetry, An Ag/AgCl reference electrode, a platinum wire counter electrode and LB film-coated ITO working electrode measured in $LiBF_4$ solution, stable up to 0.9V vs. Ag/AgCl.

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Effect of Pt Particle Size on the Durability of PEMFC (연료전지 촉매의 입자크기가 내구성에 미치는 영향)

  • Min, Kyoung-Won;Kim, Hyun-Jong;Han, M.K.;U, Yu-Tae;Kim, Mok-Soon;Chu, Young-Hwan
    • Journal of the Korean Electrochemical Society
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    • v.11 no.4
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    • pp.313-318
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    • 2008
  • The influence of the particle size of platinum(Pt) on the stability and activity was studied. The particle size of platinum was controlled in the range of $3.5{\sim}9\;nm$ by heat treatment of commercial Pt/C and confirmed by XRD and TEM. An accelerated degradation test was performed to evaluate the stability of platinum catalysts. Oxygen reduction reaction was monitored for the measurement of activity. As increasing the Pt particle size, the stability of Pt/C electrode was enhanced and the activity was reduced. It was confirmed that the stability of Pt/C electrode was in inverse proportion to the activity. PtCo/C alloy catalyst was used to improve the activity and stability of large-sized platinum particle. The maximum power density of commercial Pt/C was $507.6\;mV/cm^2$ and PtCo/C alloy catalyst was $585.8\;mV/cm^2$. The decrement of electrochemical surface area showed Pt/C(60%) and PtCo/C alloy catalyst(24%). It was possible to enhance both of stability and activity of catalyst by the combination of particle size control and alloying.

In-Situ Spectroelectrochemical Studies of Manganese(II) Oxidation

  • Zhang, Haiyan;Park, Su-Moon
    • Analytical Science and Technology
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    • v.8 no.4
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    • pp.569-574
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    • 1995
  • In-situ spectroelectrochemical studies have been carried out on the oxidation of Mn(II) at platinum, gold, lead dioxide, and bismuth doped lead dioxide electrodes. The Mn(III), $MnO_2$, and/or ${MnO_4}^-$ species are produced depending on experimental conditions employed during electrolysis. Mn(III) is shown to be produced from a very early stage during the anodic potential scan and undergo disproportionation-conproportionation reactions depending on the relative concentration of each species near the electrode surface. An oxidation mechanism consistent with these observations is proposed.

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Evaluation of High Order Statistical Parameter for Electrochemical Noise Analysis

  • Kim, Jong Jip
    • Corrosion Science and Technology
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    • v.7 no.5
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    • pp.296-299
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    • 2008
  • High order statistical parameters were evaluated using the electrochemical noise data collected during corrosion of type 430 stainless steel coupled to a inert, platinum electrode in 3.5% NaCl solution. High order statistical parameters are shown to predict uniform corrosion properly. However, Localization index, skewness of current, kurtosis and skewness of potential are capable of predicting pitting corrosion only when the transients are large with long life time. Of the high order statistical parameters evaluated, kurtosis of current is found to be the most sensitive parameter for detecting uniform and pitting corrosion.

2,3-Dichloro-5,6-Dicyano-1,4-Benzoquinone As a Redox Titrant

  • El-Brash, A.M.;El-Hussain, Laila A.
    • Archives of Pharmacal Research
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    • v.20 no.6
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    • pp.597-601
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    • 1997
  • An oxidimetric titrant, 2, 3-dichloro-5, 6-dicyano-1, 4-benzoquinone in anhydrous acetic acid is used for the semimicro-determination of hydrazine hydrate, phenylhydrazine hydrochloride, isoniazid and iproniazid phosphate in pure forms as well as in some pharmaceutical preparations containing isoniazid and iproniazid phosphate. The end point was detected potentiometrically using a platinum-calomel combination electrode. The results obtained are compared statistically with those obtained by the official methods and they are in good agreement.

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