• Membrane Journal
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• v.26 no.2
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• pp.146-151
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• 2016

Sulfonated poly (arylene ether sulfone) (SPAES) random copolymers have merits such as high proton conductivity, relatively low production cost, and thermochemical resistance when applied as polymer electrolyte membranes for fuel cells. However, it is difficult to directly employ SPAES copolymers into practical fuel cell membrane applications owing to their low chemical stability and dimensional instability under harsh operation conditions. A plausible solution is to impregnate SPAES copolymers into support films (e.g., electrospun polyimide support) with interconnected pore structures and high thermochemical toughness. In this study, a SPAES copolymer with a swivel group, which induces high free volume for fast ion transport, is chosen as ionomers to prepare pore-filling membranes (PFMs). The feasibility of the resulting membranes is evaluated via membrane characterizations.

• Bulletin of the Korean Chemical Society
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• v.32 no.6
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• pp.1902-1906
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• 2011

Sulfonated poly(fluorinated arylene ether)s (SDF-F)/poly[(N-vinylimidazole)-co-(3-methacryloxypropyl-trimethoxysilane)] (poly(VI-co-MPS))/poly(tetrafluoroethylene) (PTFE) is prepared for a high temperature proton exchange membrane fuel cell (PEMFC). The reaction of the membrane with phosphoric acid forms silicate phosphor, as a chemically bound proton carrier, in the membrane. Thus-formed silicate phosphor, nitrogen in the imidazole ring, and physically bound phosphoric acid act as proton carriers in the membrane. The physico-chemical and electrochemical properties of the membrane are investigated by various analytical tools. The phosphoric acid uptake and proton conductivity of the SDF-F/poly(VI-co-MPS)/PTFE membrane are higher than those of SDF-F/PVI/PTFE. The power densities of cells with SDF-F/poly(VI-co-MPS)/PTFE membranes at 0.6 V are 286, 302, and 320 mW $cm^{-2}$ at 150, 170, and 190 $^{\circ}C$, respectively. Overall, the SDFF/poly(VI-co-MPS)/PTFE membrane is one of the candidates for anhydrous HT-PEMFCs with enhanced mechanical strength and improved cell performance.

• 한국신재생에너지학회:학술대회논문집
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• 2010.06a
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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.

• 한국신재생에너지학회:학술대회논문집
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• 2009.11a
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• pp.195-196
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• 2009

술폰화 폴리아릴렌에테르술폰 공중합체를 기본구조로 한, 6F OH를 알코올 단량체로 사용하여 블록 공중합체를 직접 중합법으로 합성하였다. 이때 각각의 소수성-친수성 소중합체들은 동일한 분자량을 이용하여 합성했으며 그때의 두 소중합체의 몰비는 1:1로 하여 블록 공중합체의 술폰화도를 50%로 고정하였다. N-메틸-2피롤리돈(NMP) 용매 상에서 연료전지용 고분자 전해질 막을 제조하여 이온전도도 및 메탄올 투과도등의 측정을 통하여 최종 블록 공중합체 전해질 막의 기본 특성을 파악했다. 소수성-친수성 소중합체의 분자량을 조절함에 따라 최종 전해질 막의 이온 전도도를 향상시킬 수 있음이 확인되었고, 연료전지 성능 테스트 결과에서도 나피온(Nafion 115)과 비슷한 성능을 보였다.

• Proceedings of the Membrane Society of Korea Conference
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• 2008.05a
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• pp.164-164
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• 2008

• Proceedings of the Membrane Society of Korea Conference
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• 2004.05b
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• pp.133-135
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• 2004

A direct methanol fuel cells (DMFCs) using polymer electrolyte membranes are one of the most attractive power sources for a wide range of application from vehicles to portable utilities due to the stable operation at a rarely low temperature, the high energy generation yield and energy density, the simplicity of system.(omitted)

• Membrane Journal
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• v.21 no.4
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• pp.389-397
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• 2011

In this study, polymer composite membranes based on sulfonated poly(arylene ether sulfone) (SPAES) were prepared using a solution casting method with different amount of vermiculite (VMT) content. The dispersion of VMT particles in the SPAES matrix was confirmed by means of a scanning electron microscopy observation. The composite membrane containing less than 1 wt% of VMT has a smooth skin on the top and bottom, which means there is a good dispersion of VMT in the matrix. The water uptake of the composite membranes gradually increases as the temperature increases, and the results confirm that all the adsorbed water is bound water because VMT has a strong water affinity on account of its high cation exchange value. A composite membrane with a VMT content of less than 1 wt% increases the proton conductivity and reduces the methanol permeability. Of all the composite membranes, the membrane SPAES/VMT 1.0 has the best fuel cell performance in terms of membrane selectivity. The performance value of SPAES/VMT 1.0 is double that of Nafion 112, which suggests that SPAES/VMT1.0 could be an excellent candidate for direct methanol fuel cells.

• 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.

• Journal of the Korean Electrochemical Society
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• v.19 no.2
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• pp.45-49
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• 2016

In order to mitigate oxidative degradation of polymer membrane during fuel cell operation, an organic radical quencher was introduced. Rutin was selected as a radical quencher and mixed with sulfonated poly(arylene ether sulfone) to prepare composite membrane. Physicochemical properties of the composite membranes such as water uptake and proton conductivity were characterized. Hydrogen peroxide exposure experiment, which can mimic accelerated oxidative stability test during fuel cell operation, was adopted to evaluate the oxidative stability of the membranes. The composite membranes containing Rutin showed similar proton conductivity and enhanced oxidative stability compared to pristine ones.

• Journal of the Korean Electrochemical Society
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• v.17 no.1
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• pp.44-48
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• 2014

Sulfonated poly(arylene ether sulfone)-cerium composite membranes with improved oxidative stability were prepared for proton exchange membrane fuel cell application. Oxidative stability of the composite membranes changed depending on the amount of incorporated metal. Their water uptake, IEC and proton conductivity were also affected. ICP analysis confirmed trace of cerium ion in the composite membranes and $^1H$-NMR indicated successful coordination of sulfonic acid groups with the metal ions. Increasing amount of the cerium ion resulted in decrease in proton conductivities and water uptake, but enhanced oxidative stabilities. A hydrogen peroxide exposure equipment was used for the test of oxidative stability of the composite membranes, which enabled to mimic fuel cell operating condition compared with conventional Fenton's test.