• 제목/요약/키워드: Perfluorosulfonic acid

검색결과 17건 처리시간 0.03초

Self-Assembly Modification of Perfluorosulfonic Acid Membranes for the Application to Direct Methanol Fuel Cells

  • Moon, Go-Young;Rhim, Ji-Won
    • Macromolecular Research
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    • 제16권6호
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    • pp.524-531
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    • 2008
  • The mitigation or elimination of methanol crossover for perfluorosulfonic acid fuel cell membranes has been investigated extensively for direct methanol fuel cell applications with the aim of increasing the electrochemical performance and enhancing the utilization rate of methanol. Self-assembly modifications by applying an oppositely charged polyelectrolyte to Nafion membranes were attempted in order to block or reduce methanol crossover while maintaining the other advantageous properties of Nafion membranes. It was reported that anionic polyallylamine hydrochloride (PAH) was the most efficient polyelectrolyte in reducing methanol crossover, and considerable cell performance was obtained even at a methanol feed concentration of 10 M.

고분자 연료전지용 세공충진막의 제조 및 연료전지 특성 (Preparation of pore-filling membranes for polymer electrolyte fuel cells and their cell performances)

  • 최영우;박진수;이미순;박석희;양태현;김창수
    • 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.

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용액 코팅법을 통한 연료전지용 불소계 전해질 강화복합막의 특성에 미치는 분산용매의 영향 (Effect of Dispersion Solvent on Properties of Fluorinated Polymer Reinforced Composite Membrane for Fuel Cell by Solution Coating Method)

  • 육승호;윤기로;최지훈;이주성;김종민;이승우;이관영;김진영
    • Korean Chemical Engineering Research
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    • 제57권3호
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    • pp.413-419
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    • 2019
  • 최근 화석연료기반에서 친환경 수소 기반의 청정에너지원으로 전환되는 세계적 흐름에 따라, 수소연료전지의 고성능 저가격 핵심 소재 기술 개발에 많은 관심이 이루어지고 있다. 그 가운데 연료전지의 전해질로 사용되는 강화복합막의 기술 도입은 과불소계 술폰산 이오노머(Perfluorosulfonic acid, PFSA) 양의 감소 및 막 두께 감소를 통한 가격 저감 및 셀 저항 감소, 치수 안정성 개선 그리고 계면 안정성에 대한 확보가 가능하여 최종적으로 연료전지 성능 향상과 가격절감이 동시에 가능하다. 본 연구에서는 연료전지용 불소계 전해질 강화복합막 코팅 공정에서 이오노머 분산용매에 따라 막 형성 및 물성 변화와 연료전지 성능에 미치는 영향에 대해 연구하였다.

Sulfonated PEEK Ion Exchange Membranes for Direct Methanol Fuel Cell Applications

  • Moon, Go-Young;Rhim, Ji-Won
    • Macromolecular Research
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    • 제15권4호
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    • pp.379-384
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    • 2007
  • Sulfonation of polyetheretherketones (PEEK) was carried out in order to fabricate commercial perfluorosulfonic acid membrane alternatives, which were characterized in terms of their ion exchange capacity, ionic conductivity, water swelling, methanol crossover and electrochemical performance in their direct application as a methanol fuel cell. A high ion exchange capacity, 1.88, was achieved with a sulfonation reaction time of 8 h, with a significantly low methanol crossover low compared to that of Nafion. However, the morphological stability was found to deteriorate for membranes with sulfonation reaction times exceeding 8 h. Electrochemical cell tests suggested that the fabrication parameters of the membrane electrode assembly based on the sulfonated PEEK membranes should be optimized with respect to the physicochemical properties of the newly prepared membranes.

Preparation and Characterization of Poly(styrenesulfonic acid)-grafted Fluoropolymer Membrane for Direct Methanol Fuel Cell

  • Choi, Jae-Hak;Kang, Phil-Hyun;Lim, Youn-Mook;Sohn, Joon-Yong;Shin, Jun-Hwa;Jung, Chan-Hee;Jeun, Joon-Pyo;Nho, Young-Chang
    • Korean Membrane Journal
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    • 제9권1호
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    • pp.52-56
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    • 2007
  • A proton exchange membrane was prepared by ${\gamma}-irradiation-induced$ grafting of styrene into poly(tetrafluoro-ethylene-co-perfluoropropyl vinyl ether) (PFA) and subsequent sulfonation reaction. The degree of grafting (DOG) increased with an increase in the absorbed dose. The prepared membranes showed high ion exchange capacity reaching 3.0 meq/g, which exceeded the performance of commercially available perfluorosulfonic acid membranes such as Nafion. The proton conductivity of PFA-g-PSSA membrane increased with the DOG and reached 0.17 S/cm for the highest sample at room temperature. The DMFC performance of the prepared membranes with 50% DOG was comparable to that of Nafion membrane.

산-염기형 PEEK와 PSf를 이용한 고체 고분자전해질 복합막의 가교화 (Cross-linking of Acid-Base Composite Solid Polymer Electrolyte Membranes with PEEK and PSf)

  • 장인영;장두영;권오환;김경언;황갑진;심규성;배기광;강안수
    • 한국수소및신에너지학회논문집
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    • 제17권2호
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    • pp.149-157
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    • 2006
  • Hydrogen as new energy sources is highly efficient and have very low environmental emissions. The proton exchange membrane fuel cell (PEMFC) is an emerging technology that can meet these demands. Therefore, the preparation of stable polymeric membranes with good proton conductivity and durability are very important for hydrogen production via water electrolysis with PEM at medium temperature above $80^{\circ}C$. Currently Nafion of Dupont and Aciflex of Asahi, etc., solid polymer electrolytes of perfluorosulfonic acid membrane, are the best performing commercially available polymer electrolytes. However, these membrane have several flaws including its high cost, and its limited operational temperature above $80^{\circ}C$. Because of this, significant research efforts have been devoted to the development of newer and cheaper membranes. In order to make up for the weak points and to improve the mechanical characteristics with cross -linking, acid-base complexes were prepared by the combination PSf-co-PPSS-$NH_2$ with PEEK-$SO_3H$. The results showed that the proton conductivity decreased in 17.6% and 40% but tensile strength increased in 78% and 98%, about $20.65\;{\times}\;10^6N/m^2$, in comparison with SBPSf/HPA and SPEEK/HPA complex membrane.

Advances in Materials for Proton Exchange Membrane based Fuel Cells

  • McGrath James E.
    • 한국고분자학회:학술대회논문집
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    • 한국고분자학회 2006년도 IUPAC International Symposium on Advanced Polymers for Emerging Technologies
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    • pp.58-59
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    • 2006
  • Less than a decade ago, most alternate membrane materials for fuel cells relied upon a post-sulfonation process to generate ionic groups capable of transporting protons from the anode to the cathode. These random post sulfonations showed some promise, but in general they produced materials that were not sufficiently stable or protonically conductive at ion exchange capacities where aqueous swelling could be restricted. Our group began to synthesize disulfonated monomers that could be used to incorporate into random copolymer proton exchange membranes. The expected limitation was that the aromatic polymers might not be stable enough to withstand fuel cell conditions. However, this was mostly based upon an accelerated test known was the Fenton's Reagent Test, which did not seem to this author as being a reliable predictor of performance. A much better approach has been to evaluate the open circuit voltage (OCV) for alternate membranes, as well as the benchmark perfluorosulfonic acid systems. When this is done, the aromatic ionomers of this study, primarily based upon disulfonated polyarylene ether sulfones, show up quite well. Real time 3000 hours DMFC results have also been generated. Obtaining conductive materials at low humidities is another major issue where alternate membranes have not been particularly successful. In order to address this problem, multiblock copolymers with relatively high water diffusion coefficients have been designed, which show promise for conductivity at lowered humidity.

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저전류/저가습 조건에서 고분자전해질 막 열화 (Degradation of Polymer Electrolyte Membrane under Low Current/Low Humidity Conditions)

  • 김태희;이정훈;이호;임태원;박권필
    • 한국수소및신에너지학회논문집
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    • 제18권2호
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    • pp.157-163
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    • 2007
  • During PEMFC operation, low current and low humidity conditions accelerate the degradation of perfluorosulfonic acid membrane. But, there have been no studies that clearly explain why these conditions accelerate the membrane degradation. In this study, the hydrogen permeability through the membrane, I-V polarization of MEA, fluoride emission rate(FER) in effluent water were measured during cell operation under low current densities and low relative humidity(RH). The experimental results were evaluated with oxygen radical mechanism the most commonly known for membrane degradation. It seems that low RH of anode is a good condition for $H{\cdot}$ radical formation on the Pt catalyst and the low current condition accelerates the $H{\cdot}$ to form $HO_2{\cdot}$ radical attacking the polymer membrane.

마이크로 펌프 응용을 위한 이온성 고분자-금속 복합체를 이용한 멤브레인형 마이크로 액추에이터 제작에 관한 연구 (A Study on the Fabrication of a Membrane Type Micro=Actuator Using IPMC(Ionic Polymer-Metal Composite) for Micro-Pump Application)

  • 조성환;이승기;김병규;박정호
    • 대한전기학회논문지:전기물성ㆍ응용부문C
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    • 제52권7호
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    • pp.298-304
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    • 2003
  • IPMC(Ionic Polymer-Metal Composite) is a highly sensitive actuator that shows a large deformation in presence of low applied voltage. Generally, IPMC can be fabricated by electroless plating of platinum on both sides of a Nafion (perfluorosulfonic acid) film. When a commercial Nafion film is used as a base structure of the IPMC membrane, the micro-pump structure and the IPMC membrane are fabricated separately and then later assembled, which makes the fabrication inefficient. Therefore, fabrication of an IPMC membrane and the micro-pump structure on a single wafer without the need of assembly have been developed. The silicon wafer was partially etched to hold liquid Nafion to be casted and a 60-${\mu}{\textrm}{m}$ thick IPMC membrane was realized. IPMC membranes with various size were fabricated by casting and they showed 4-2${\mu}{\textrm}{m}$ displacements from $4mm{\times}4mm$ , $6mm{\times}6mm$, $8mm{\times}8mm$ membranes at the applied voltage ranging from 2Vp-p to 5Vp-p at 0.5Hz. The displacement of the fabricated IPMC membranes is fairly proportional to the membrane area and the applied voltage.