• Membrane Journal
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• v.20 no.1
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• pp.40-46
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• 2010

In this study, we manufactured the membrane using the polyethersulfone (PES) of fiber by using the electrospinning method. The polymer electrolyte membrane for fuel cells was manufactured by impregnating Nafion solution to the porous PES membrane. We confirmed that electrospun PES membrane has higher thermal stability than Nafion 212 membrane by thermogravimetric analysis. Impregnated Nafion in the pores of the electrospun PES membrane was characterized by scanning electron microscopy. The AC impedance data shows the hydrogen ionic conductivity of $10^{-2}$ S/cm below $100^{\circ}C$. Nafion impregnated PES membrane shows the maximum performance at $90^{\circ}C$ showing current density of 389 mA/$cm^2$ at 0.6 V, while Nafion 212 membrane shows maximum at $75^{\circ}C$.

• Proceedings of the Korea Society for Energy Engineering kosee Conference
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• 2002.05a
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• pp.115-119
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• 2002

고분자 전해질 연료전지는 전해질로 고체고분자막을 사용하는 연료전지로 고분자막은 수소 이온의 활발한 전달을 위해 일정량의 수분이 존재해야 한다. 따라서 연료전지의 운전 중에 고분자막은 항상 수화되어 있어야 하며 수분이 부족하게 되면 수소이온 전도도가 떨어지고, 막의 수축으로 인해 전극과 막 계면의 저항이 증가한다. 반대로 수분이 많이 존재하면 촉매 표면에 반응기체의 확산이 어려워져 전지 성능이 감소하게 된다.(중략)

• Membrane Journal
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• v.32 no.6
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• pp.442-455
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• 2022

High-temperature polymer electrolyte membrane fuel cell (HT-PEMFC) has been studied as an alternative to low-temperature PEMFC due to its fast activation of electrodes and high resistance to electrode poisoning by carbon monoxide. It is highly required to develop stable PEMs operating at high temperatures even doped by ion-conducting materials for the development of high-performance and durable HT-PEMFC systems. A number of studies have been conducted to develop polybenzimidazole (PBI)-based PEMs for applications in HT-PEMFC due to their high interaction with doped ion-conducting materials and outstanding thermomechanical stability under high-temperature operation. This review focused on the development of PBI-based PEMs showing high performance and durability. Firstly, the characteristic behavior of PBI-based PEMs doped with various ion-conducting materials including phosphoric acid was systematically investigated. And then, a comparison of the physicochemical properties of the PEMs according to the different membrane manufacturing processes was conducted. Secondly, the incorporation of porous polytetrafluoroethylene substrate and/or inorganic composites to PBI matrix to improve the membrane performances was studied. Finally, the construction of cross-linked structures into PBI-based PEM systems by polymer blending method was introduced to improve the PEM properties.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.08a
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• pp.197-197
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• 2012

염료감응형 태양전지 (DSSC)는 다양한 태양전지 중, 가장 환경친화적이고, 생산단가도 낮을 뿐만 아니라 다양한 색상과 투광성을 확보할 수 있어 많은 연구가 진행되어왔다. 하지만 액체 전해질을 사용하는 기존 염료감응형 태양전지는 높은 휘발성과 열 팽창 수축에 따른 전해질 누액의 문제점으로 인하여 최근에는 고체전해질을 이용한 염료감응형 태양전지의 개발이 활발히 이루어지고 있다. 본 연구에서는 스크린 프린팅법을 이용하여 TiO2 광전극을 코팅하고 Mg(OH)2를 솔-젤법을 이용하여 스핀 코팅 하였다. 이후에 $500^{\circ}C$에서 1시간동안 열처리를 통해 MgO 나노 코팅막을 형성하여 고체 박막 태양전지(solid state dye sensitized solar cells)을 제작하였다. MgO 나노 코팅막의 특성은 솔라시뮬레이터를 이용하여 I-V 곡선, transient Voc, dark current를 측정하였고, UV0vis spectroscopy를 이용하여 염료흡착량을 분석하여 코팅막과 효율간의 상관관계를 평가하였다.

• Proceedings of the Korea Society for Energy Engineering kosee Conference
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• 2002.05a
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• pp.143-148
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• 2002

SPE(solid polymer electrolyte) 수전해법은 고체고분자전해질 막(membrane)을 전해질로 사용하는 방법으로서 이 전해질 막은 알칼리 수전해에서의 KOH전해질과 격리막을 합쳐놓은 것과 같은 역할을 수행한다. SPE 수전해는 양극(anode)에서 촉매 전극에 의해 물로부터 산소기체(O$_2$)와 수소이온(H$^{+}$)이 발생되며 수소이온(H$^{+}$)은 다량의 물($H_2O$)분자와 함께 고체고분자전해질 막을 통하여 음극으로 이동하여 외부회로를 통해 도달한 전자(e)와 음극(cathode)에서 만나 수소기체(H$_2$)를 발생시키는 방법이다.(중략)

• Journal of the Korea Institute of Information and Communication Engineering
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• v.10 no.6
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• pp.1088-1094
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• 2006

In this paper, we establish a mode oxidation process for formation of $Ta_2O_5$ insulator film. The voltage drop in the electrolyte is affected not in voltage change but in current change. If the voltage drop in the electrolyte is same with cathode oxidation voltage, the current changes logarithmically in proportion to the voltage drop in interface of Ta2O5/electrolyte. As a result of the measurement on the electrical property of $Ta_2O_5$ insulator film, when the thickness of the insulator film is $1500\AA$, the breakdown voltage is 350volts Ind dielectric constant is 29.

• Membrane Journal
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• v.11 no.1
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• pp.22-28
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• 2001

Various charged homogeneous membranes were fabricated by blending of ionic polymer with a non-ionic polymer with different ratios. In this study. sodium alginate, chitosan and poly(vinyl alcohol) were employed as anionic. cationic and non-ionic polymers, respectively. The permcation and separation behaviors of aquCOll::; salt solutions have been investigated through the charged membranes. As the content of ionic polymer increases in the membrane, the hydrophilicity of the membrane increases and pure water flux as well as solution flux increases correspondingly, indicating that the permeation performance through the membrane is cletemunecl mainly by its hydrophilicity-, Electrostatic interaction between the charged membrane and ionic solute molecules, that is. Donnan exclusion was observed to be attributed to salt rejection to a great deal of extent, and molecular sieve mechanism was effective [or the separation of the salt solution under a similar electrostatic circumstance of solutes.

• Membrane Journal
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• v.26 no.6
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• pp.458-462
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• 2016

Saline water electrolysis, known as chlor-alkali (CA) membrane process, is an electrochemical process to generate valued chemicals such as chlorine, hydrogen and sodium hydroxide with high purities higher than 99%, using an electrolytic cell composed of cation exchange membrane, anode and cathode. It is necessary to reduce energy consumption per a unit chemical production. This issue can be solved by decreasing intrinsic resistance of the membrane and the electrodes and/or by reducing their interfacial resistance. In this study, the electron radiation grafting of a $Na^+$ ion-selective polymer was conducted onto a hydrocarbon sulfonated ionomer membrane with high chemical resistance. This approach was effective in improving electrochemical efficiency via the synergistic effect of relatively fast $Na^+$ ion conduction and reduced interfacial resistance.

• Proceedings of the Membrane Society of Korea Conference
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• 2003.11a
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• pp.51-54
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• 2003

• Proceedings of the Membrane Society of Korea Conference
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• 2008.05a
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• pp.206-209
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• 2008