• Transactions of the Korean hydrogen and new energy society
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• v.28 no.5
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• pp.465-470
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• 2017

Sulfonated fluorinated block copolymers having diphenyl units were mixed with the sulfonated cationic conductive polymers at an optimum mixing ratio to form hybrid membranes for fuel cells and their characteristics were studied. 2D and 3D AFM topology analysis confirmed that the number of hydrophilic units in the hybrid membrane was improved. Through the FE-SEM, the microstructure of the hybrid membrane implied hydrogen bonding and pi-pi interactions, and EDAX confirmed carbon, oxygen, sulfur, and fluorine. The thermogravimetric analysis showed that the hybrid membrane was thermally stable and the hydrophilicity of the hybrid membrane was increased by the contact angle of water droplets. As a result, it was confirmed that the cation conductivity increased by a factor of 1.8 times as the number of acidic domains in the hybrid film increased.

• Journal of the Korean Chemical Society
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• v.39 no.9
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• pp.722-727
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• 1995

The electrochemical impedance spectra of polyaniline film prepared by cyclic voltammetry have been investigated in 0.1 M aqueous sulfuric acid solution. Charge transfer resistances were rather low at the oxidized states in agreement with the conductive behavior reported at these potentials. The corresponding exchange current densities were very high. Large values of capacitance associated with the polymer have been found which vary as a function of the electrode potentials. An equivalent electrical circuit has been deduced from the impedance data. It was therefore possible to obtain the parameters of the ionic mass transport within the film.

• Proceedings of the Korean Fiber Society Conference
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• 2001.10a
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• pp.29-32
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• 2001

Conductive polymers(CPs) are a relatively new class of organic materials displaying as their foremost property a high conductivity combined with very light weight, flexibility and reasonably facile processability[1]. Due to their high conductivity/weight ratio, they have recently evinced much interest in potential application as EMI shielding screens, coatings or jackets for flexible conductors, rechargeable batteries and as possible substitutes for metallic conductors or semiconductors in wide variety of electrical devices[2]. (omitted)

• Proceedings of the KIEE Conference
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• 2000.07c
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• pp.1788-1790
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• 2000

본 논문에서는 마이크로 바이오 센서에 응용하기 위한 기초 실험으로서 다공성 실리콘을 이용한 요소 센서의 특성을 고찰하였다. 센서의 감도나 내구성 측면에서 보면 전도성 고분자를 전기중합(electropolymerization)한 후 효소를 전착(electrodeposition)하여 고정화하는 것보다는 PSi 표면에 효소를 코팅한 후 그 위에 고분자를 전기 중합하는 것이 유리하였다. SEM 이미지와 EDX 스펙트럼 분석 결과로부터 urease와 polypyrrole(PPy)이 다공질 실리콘 표면에 코팅되었음을 알 수 있었으며, 요소 농도가 1mM$\sim$1M 영역(일반적인 혈중 요소 농도는 $20{\mu}M{\sim}30{\mu}M$)에서 감도는 $30{\mu}A/decade$ 였다.

• Proceedings of the Membrane Society of Korea Conference
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• 2003.07a
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• pp.51-55
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• 2003

Membranes made with perfluorinated polymers are of particular interest due to the unique features demonstrated by these materials. Both highly hydrophobic and hydrophilic membranes have been developed from appropriate perfluoropolymers, which were in turn obtained by copolymerization of TFE with special monomers available at the industrial scale. Highly hydrophobic membranes obtained from the glassy copolymers of TFE and 2,2,4 trifluoro-5 trifluoromethoxy-1,3 dioxole (Hyflo $n^{ }$ AD) show properties which make them particularly suited for use in the field of gas-liquid contactors and membrane distillation. Hydrophylic highly conductive proton exchange membranes obtained from the copolymer of TFE and a short-side-chain (SSC) perfluorosulfonylfluoridevinylether (Hyflo $n^{ }$ Ion) find interesting application in the field of fuel cells, especially in view of the current tendency to move to high temperature operation.n.

• Journal of the Korean institute of surface engineering
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• v.48 no.3
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• pp.87-92
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• 2015

Carbon thin films were deposited on STS 316L sheets by inductively coupled plasma enhanced magnetron sputtering with or without substrate bias voltage. Typical Raman spectrum for amorphous diamond-like carbon (DLC) was obtained, and the interfacial contact resistance (ICR) was measured to show its conductive nature. The electrochemical impedance spectroscopy (EIS) was used to investigate the corrosion mechanism of the carbon coating under the polymer electrolyte membrane fuel cell (PEMFC) condition. According to the pore-corrosion mechanism, the electrolyte penetrates the carbon coating through the pores and reacts with the substrate. As the substrate corrosion proceeds, the pore enlargement occurs and the surface area of the substrate exposed to the electrolyte. Applicability of the carbon coating for the PEMFC bipolar plate was evaluated by potentiodynamic polarization experiments. Finally, an adhesion problem was briefly considered.

• Journal of the Korean Society of Safety
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• v.12 no.2
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• pp.65-69
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• 1997

Especially, Fiber glass Reinforced Plastics(FRP) is the best composite insulating material which has been so far. Therefore, it's worthy of notice to investigate on the corona electrified composite insulating material by surface condition. And then some other materials will be focussed on. In this study, charge decay were measured with charging-time and grid voltage on FRP composite material surface in order to analyze the mechanism. As a result we have studied that the way of the composite glass fiber(GF) and Polymer and the condition of the contaminated surface was different. In case of the GF is mixed with vertical, charge decay speed is fast because the charge is easily leaked. On the other hand, the surface charge decay speed is depend on conductive or insulated of the contaminant.

• Proceedings of the KIPE Conference
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• 2012.07a
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• pp.592-593
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• 2012

Buck converter must operate at fairly high switching frequency for miniaturizing a whole circuit and achieving a fast response. However, at the conditions of low output voltage, high output current, and high switching frequency, the influence of parasitic elements to circuit operation will become extremely obvious. In this paper, it has been shown that these parasitic elements of output capacitor link the ripple of the output voltage. The MCP capacitors and aluminum electrolytic capacitors are applied to the buck converter and observed characteristics and the experimental results were reported.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2006.04a
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• pp.39-40
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• 2006

We prepared ZnO:Al (AZO) thin films on polycarbonate (Pc) and polyethersulfon (PES). Because the polymer substrate has weak thermal resistance. The AZO thin films were deposited at room temperature by facing targets sputtering (FTS) method In the work, AZO thin films were deposited with different thickness in 1mTorr and $O_2$ gas flow rate 0.05. The electrical, optical and crystallographic properties were measured From the results, the resistivity of $7.3{\times}10^{-4}{\Omega}cm$ and transmittance of over 80% in visible range were obtained.

• Elastomers and Composites
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• v.56 no.3
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• pp.117-123
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• 2021

Electronic skin (or E-skin) is an artificial smart skin composed of one or more than two sensors. E-skins detect external stimuli and convert them into electrical signals. Various types of E-skin sensors exist, including mechanical, physical, and chemical, depending on the detection signals involved. For wearable E-skins with superior sensitivity and reliability, developing conductors that possess both good elasticity and sensitivity is essential. Typical electrical conductors used in these sensors show very high sensitivity, but they have drawbacks such as non-linearity, irreversibility, and a narrow sensing range. To address these issues, stretchable and lightweight ionic conductors have been actively used in E-skin applications. This study summarizes the recent progress on various types of ionic conductors and ionic-conductor-based E-skin sensors.