• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2009년도 춘계학술대회 논문집
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• pp.278-281
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• 2009

Proton exchange membrane is the key material for proton exchange membrane fuel cells (PEMFC). Currently widely-used perfluorosulfonic acid membranes have some disadvantages, such as low thermal stability, easy swelling, excessive crossover of methanol and high price etc. Other membranes, including sulfonated polymer, radiation grafted membranes, organic-inorganic hybrids and acid-base blends, do not satisfy the criteria for PEMFC, which set a barrier to the development and commercialization of PEMFC. Pore-filling type proton exchange membrane is a new proton exchange membrane, which is formed by filling porous substrate with electrolytes. Compared with traditional perfluorosulfonic acid membranes, pore-filling type proton exchange membranes have many advantages, such as non- swelling, low methanol permeation, high proton conductivity, low cost and a wide range of materials to choose. In this research, preparation methodology of pore-filling membranes by particularly using all hydrocarbon polymers and fuel cell performances with the membranes are evaluated.

• Korean Membrane Journal
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• 제6권1호
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• pp.44-54
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• 2004

Organic-inorganic composite membranes based on sulfonated poly(phthalazinone ether sulfone) (sPPES)/silica hybrid were prepared using the sol-gel process under acidic conditions. The sulfonation of PPES with concentrated sulfuric acid as sulfonation agent was carried out to prepare proton exchange membrane material. The behaviors of the proton conductivity and methanol permeability are depended on the sulfonation time (5-100 hr). The hybrid membranes composed of highly sulfonated PPES (IEC value: 1.42 meq./g) and silica were fabricated from different silica content (5-20 wt%) in order to achieve desirable proton conductivity and methanol permeability demanded for fuel cell applications. The silica particles within membranes were used for the purpose of blocking excessive methanol cross-over and for forming the path way to transport of the proton due to absorbing water molecules with ≡SiOH on silica. The presence of silica particles in the organic polymer matrix results in hybrid membranes with reduced methanol permeability and improved proton conductivity.

• 멤브레인
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• 제26권2호
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• pp.135-140
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• 2016

본 연구에서는 고분자전해질 연료전지의 전해질막의 성능향상을 위하여 철산화물(Ferroxane)과 나피온을 이용하여 유무기 복합막을 개발하였다. 아세트산을 이용하여 안정화시킨 lepidocrocite을 이용한 ferroxane 나노입자를 합성하였고, 이를 나피온과 혼합하여 복합막들을 제조하였다. 제조된 복합막들의 성능 및 열안정성을 평가하기 위해 이온전도도, 이온교환용량(IEC), 함수율 및 TGA 측정을 수행하였다. 그 결과 ferroxane 나노입자를 함유한 나피온 복합막의 수소이온전도도가 리캐스팅한 나피온막보다 높은 이온전도도 및 이온교환용량을 보였으며, 높은 열적 안정성 결과를 얻었다. 최고 성능의 복합막의 수소이온전도도는 $0.09S\;cm^{-1}$이며, 이온교환용량은 $0.906meq\;g^{-1}$을 보였다.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2010년도 춘계학술대회 초록집
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• pp.147-147
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• 2010

An electrolyte membranes for high temperature/low humidity is a demand for the proton exchange membrane fuel cells (PEMFCs). In this work, we prepared hybrid membranes, which have novel glass content in the hydrophilic and hydrophobic part of sulfonated poly(arylene ether sulfone) (SPAES) by in-situ sol-gel synthesis of various functional silane. The effect of silicate from functional silane content on the proton conductivity, water uptake of the hybrid membranes under high temperature and low humidity was quantitatively identified. The silicate content contributed to the enhancement of not only proton conductivity, but also water retention ability for PEMFCs operation.

• 전기화학회지
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• 제15권1호
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• pp.35-40
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• 2012

The composite membranes using Nafion as matrix and 1-ethyl-3-methylimidazolium tetracyanoborate (EMITCB) as ion-conducting medium in replacement of water were prepared and characterized. The amount of EMITCB in Nafion varied from 30 to 50wt%. The composite membranes are characterized by ion conductivity, thermogravitational analyses (TGA) and small-angle X-ray scattering (SAXS). The composite membranes containing EMITCB of 40wt% showed the maximum ionic conductivity which was ~0.0146 S $cm^{-1}$ at 423.15 K. It is inferred that the decrease in ionic conductivity of all the composite membranes might be due to the decomposition of a tetracyanoboric acid formed in the composite membranes. The results of SAXS indicated that the ionic clusters to conduct proton in the composite membranes were successfully formed. In accordance with the results of ionic conductivity as a function of a reciprocal temperature, SAXS showed a proportional decrease in scattering maximum $q_{max}$ as the amount of EMITCB increases in the composite membranes, which results in the increase in ionomer cluster size. The TGA showed no significant decomposition of the ionic liquid as well as the composite membranes in the range of operating temperature ($120-150^{\circ}C$) of high temperature proton exchange membrane fuel cells (HTPEMFC). As a result, EMITCB is able to play an important role in transferring proton in the composite membranes at elevated temperatures with no external humidification for proton exchange membrane fuel cells.

• 한국막학회:학술대회논문집
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• 한국막학회 2004년도 Proceedings of the second conference of aseanian membrane society
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• pp.29-32
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• 2004

Reduction of methanol crossover in proton exchange membranes (PEMs) can be achieved by 1) the selection of materials, 2) the morphology control, and 3) the adequate crosslinking [1, 2]. The selection of polymer matrix of PEM for direct methanol fuel cells (DMFCs) is very important because the proton conductivity and methanol permeability are largely dependent upon the properties of polymers.(omitted)

• 전기화학회지
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• 제12권3호
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• pp.219-233
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• 2009

Mobile devices in the next generation such as camera, cell phone, network, Note PC, etc. require higher power and energy sources due to convergences of various functions. Direct methanol fuel cell (DMFC) has been focused as an attractive power source, but there are critical issues involved in its commercialization with regard to the core technologies of materials, components, and system. The requirements of key technologies are differentiated from applications and fuel supply methods. Here, the roles of the proton-conducting membrane are discussed and the current status of DMFC systems is discussed in terms of proton conductivity, methanol permeability, and water management. Materials such as perfluorinated and partially fluorinated membranes, hydrocarbon membranes, composite membranes, and other modified ionomers have been studied. These would explain the critical issues of DMFC and the role of membranes for commercialization.

• 멤브레인
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• 제26권5호
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• pp.329-336
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• 2016

수소이온 교환막(PEM; Proton Exchange Membrane)은 연료전지 막-전극 복합체(MEA; Membrane-electrode Assembly)를 구성하는 핵심 소재 중 하나로서, 촉매와 함께 연료전지 성능을 결정하는 중요한 역할을 한다. 이러한 수소이온교환막의 성능은 내부에 존재하는 수소이온 전달 통로인 수화 채널의 구조에 큰 영향을 받는 것으로 알려져 있다. 분자 동역학(MD; Molecular Dynamics) 전산모사 기술은 이러한 소재 내부의 분자 및 원자구조를 파악하기 위한 유용한 도구로서, 수소이온 교환막의 구조 및 특성에 관한 많은 관련 연구가 진행되고 있다. 본 총설에서는 분자동역학 전산모사 관련 연구에 대한 동향을 정리하고, 이를 통해 어떤 구조적 특징들을 분석할 수 있는지 제시하여, 수소이온 교환막 연구자들과 분리막 연구자들에게 분자동역학 전산모사 기술의 유용성에 대하여 소개하고자 한다.

• 한국수소및신에너지학회논문집
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• 제28권1호
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• pp.24-29
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• 2017

A fluorinated polybenzimidazole (FPBI) was synthesized from 3,3-diaminobenzidine (DAB) of tetraamine, 2,2-bis(4-carboxyphenyl)hexafluoropropane of aromatic biscarboxylic acid, and 4,4-sulfonyldibenzoic acid of aromatic biscarboxylic acid in polyphosphoric acid (PPA). A FPBI was easily cast and made into clear films. The structure of condensation polymers and corresponding membranes were analyzed using GPC (gel permeation chromatography), $^1H$-NMR ($^1H$ nuclear magnetic resonance) and FT-IR (fourier transform infrared). TGA (thermogravimetric analysis) analysis showed that the prepared membranes were thermally stable, so that elevated temperature fuel cell operation would be possible. The proton conductivity of the FPBI membranes increased with increasing temperatures in the polymer. A FPBI membrane has a maximum ion conductivity of 45 mS/cm at $90^{\circ}C$ and 100% relative humidity.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2009년도 춘계학술대회 논문집
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• pp.282-285
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• 2009

This study presents preparation and characterization of composite membranes based on ionic liquids. The ionic liquids act as water in sulfonated membranes. On the behalf of ionic conduction through ionic liquid inside the membranes, non-aqueous membranes showed Arrenhius dependence on temperature with no external humidification. It was implied that hopping mechanism of proton was dominant in the ionic liquid based membranes. In addition, small angle X-ray (SAXS) studies provided the information on morphology of ionic clusters formed by the interaction between sulfonic acid groups of the polymers and ionic liquids. The SAXS spectra showed matrix peaks, ionomer peaks and Prodo's law for Nafion based composite membranes and only matrix peaks for hydrocarbon based ones. However, ionic conductivity and atomic force microscopy (AFM) images showed the clear formation of ionic clusters of the hydrocarbon based composite membranes. It implies for ionic liquid based high temperature membranes that it is important to use sulfonated polymers as solid matrix of ionic liquid which can form clear ionic clusters in SAXS spectra.