• Title, Summary, Keyword: Polymer electrolyte membrane

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Silver Polymer Electrolyte Membranes for Facilitated Olefin Transport: Carrier Properties, Transport Mechanism and Separation Performance

  • Kim, Jong-Hak;Kang, Yong-Soo
    • Macromolecular Research
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    • v.12 no.2
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    • pp.145-155
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    • 2004
  • Facilitated transport membranes for the separation of olefin/paraffin mixtures have long been of interest in separation membrane science because olefins, such as propylene and ethylene, which are important chemicals in petrochemical industries, are currently separated by energy-intensive cryogenic distillation processes. Recently, solid polymer electrolyte membranes containing silver ions have demonstrated remarkable performance in the separation of olefin/paraffin mixtures in the solid state and, thus, they can be considered as alternatives to cryogenic distillation. Here, we review recent progress, and critical issues affecting in the use of facilitated olefin transport membranes; in particular, we provide a general overview with reference to carrier properties, transport mechanisms, and separation performance.

Sulfonated Dextran/Poly(vinyl alcohol) Polymer Electrolyte Membranes for Direct Methanol Fuel Cells

  • Won, Jong-Ok;Ahn, Su-Mi;Cho, Hyun-Dong;Ryu, Ji-Young;Ha, Heung-Yong;Kang, Yong-Soo
    • Macromolecular Research
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    • v.15 no.5
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    • pp.459-464
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    • 2007
  • Polymer electrolyte membranes, featuring ionic channels, were prepared from sulfonated dextran/ poly(vinyl alcohol) (sD/PVA) membranes. A stiff sulfated dextran was chosen as the route for ionic transport, since ionic sites are located along the stiff dextran main chain. The sD/PVA blend membranes were annealed and then chemically crosslinked. The characteristics of the crosslinked sD/PVA membranes were investigated to determine their suitability as proton exchange membranes. The proton conductivity was found to increase with increasing amounts of sD inside the membrane, which reached a maximum and then decreased when the sD content exceeded 30 wt%, while the methanol permeability increased with increasing sD content. The good dispersion of sD inside the membrane, which serves as an ionic channels mimic, played a significant role in proton transportation.

Influence of the Catalyst Composition on Electrode Performance for Polymer Electrolyte Membrane Fuel Cells (촉매조성이 PEM용 연료전지의 전극특성에 미치는 영향)

  • 임재욱;최대규;류호진
    • Journal of the Microelectronics and Packaging Society
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    • v.9 no.3
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    • pp.43-48
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    • 2002
  • In this study, high performance electrode catalyst was developed in fabrication of membrane electrode assembly for PEMFCs(Polymer Electrolyte Membrane Fuel Cells). The I-V characteristics were measured to evaluate the influence of Nafion solution and Pt loading amount in the catalyst composition. The electrode characteristics were also investigated with respect to temperature change. The electrode performance was optimized at Nafion 5 wt% and 0.5 mg Pt/$\textrm{cm}^2$ content. The increase in the concentration of Nafion solution resulted in the decrease in electrode performance. At $80^{\circ}C$ of unit cell, I-V characteristics excelled those obtained at lower temperature. There was no difference in performance at low current density, but the improvement of voltage value in higher temperature could be found at high current density.

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Effect of Electrolyte on Preperation of Porous Alumina Membrane by Anodic Oxidation (양극산화에 의한 다공성 알루미나 막의 제조시 전해질의 영향)

  • Lee, Chang-Woo;Hahm, Yeong-Min;Kang, Hyun-Seop;Chang, Yoon-Ho
    • Applied Chemistry for Engineering
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    • v.9 no.7
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    • pp.1047-1052
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    • 1998
  • The porous alumina membrane was prepared from aluminum metal(99.8%) by anodic oxidation using DC power supply of constant current mode in aqueous solution of sulfuric, oxalic, phosphoric and chromic acid. Pore size and distribution, membrane thickness, morphology and crystal structure were examined with several anodizing conditions : reaction temperature, electrolyte concentration, current density and electrolyte type. It was found that ultrafiltration membrane was fabricated in electrolyte of sulfuric, and oxalic acid. On the other hand, microfiltration membrane was fabricated in electrolyte of phosphoric, and chromic acid. Also, it was shown that crystal structure of porous alumina membrane prepared in sulfuric, oxalic, and phosphoric acid was amorphous, whereas porous alumina membrane prepared in chromic acid had ${\gamma}$ type of crystal structure.

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Polymer Materials for Polymer Electrolyte Fuel Cells: Sulfonated Poly(ether sulfone)s for Fuel Cell Membranes

  • Kim, H.J.;Lee, S.Y.;Cho, E.;Ha, H.Y.;Oh, I.H.;Lim, T.H.
    • Proceedings of the Polymer Society of Korea Conference
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    • pp.185-185
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    • 2006
  • The performances of proton exchange membrane fuel cell (PEMFC), direct formic acid fuel cell (DFAFC) and direct methanol fuel cell (DMFC) with sulfonated poly(ether sulfone) membrane are reported. Pt/C was coated on the membrane directly to fabricate a MEA for PEMFC operation. A single cell test was carried out using $H_2/air$ gases as fuel and oxidant. A current density of $730\;mA/cm^2$ at 0.60 V was obtained at $70^{\circ}C$. Pt-Ru (anode) and Pt (cathode) were coated on the membrane for DMFC operations. It produced $83\;mW/cm^2$ of maximum power density. The sulfonated poly(ether sulfone) membrane was also used for DFAFC operation under several different conditions. It showed good cell performances for several different kinds of polymer electrolyte fuel cell applications.

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Research and Development Trend of Electrolyte Membrane Applicable to Water Electrolysis System (수전해 시스템에 적용 가능한 전해질막 연구 개발 동향)

  • Im, Kwang Seop;Son, Tae Yang;Kim, Kihyun;Kim, Jeong F.;Nam, Sang Yong
    • Applied Chemistry for Engineering
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    • v.30 no.4
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    • pp.389-398
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    • 2019
  • Hydrogen energy is not only a solution to climate change problems caused by the use of fossil fuels, but also as an alternative source for the industrial power generation and automotive fuel. Among hydrogen production methods, electrolysis of water is considered to be one of the most efficient and practical methods. Compared to that of the fossil fuel production method, the method of producing hydrogen directly from water has no emission of methane and carbon dioxide, which are regarded as global environmental pollutants. In this paper, the alkaline water electrolysis (AWE) and polymer electrolyte membrane water electrolysis (PEMWE), which are one of the hydrogen production methods, were discussed. Recent research trends of hydrocarbon electrolyte membranes and the crossover phenomenon of electrolyte membranes were also described.

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

  • Choi, Young-Woo;Park, Jin-Soo;Lee, Mi-Soon;Park, Seok-Hee;Yang, Tae-Hyun;Kim, Chang-Soo
    • 한국신재생에너지학회:학술대회논문집
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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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Air Pumps for Polymer Electrolyte Membrane Fuel Cells (휴대용 고분자전해질막 연료전지의 산화제 공급을 위한 전기침투 현상 기반의 공기펌프의 개발)

  • Kwon, Kil-Sung;Kim, Dae-Joong
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.34 no.7
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    • pp.715-720
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    • 2010
  • We propose an electroosmosis-based air delivery scheme for polymer electrolyte fuel cells and experimentally investigate its feasibility. An electroosmotic pump under a low-frequency AC electric field is used to displace initially a volume of pump working liquids. This working liquid is then pumped into a space enclosed by a flexible membrane and the movement of the membrane delivers air to a fuel cell. We successfully demonstrated the operation of a forced-convection fuel cell using this technique. In this preliminary study, however, the power consumption of the pump exceeds the power generated by the fuel cell. We conclude this paper with a discussion of several ways to reduce the pump-to-fuel cell power ratio.

Perfonnance Evaluation of Single Cell and Stack of PolymerElectrolyte Fuel Cell by Using Transfer Printing Technique

  • KIM, CHANG SOO;CHUN, YOUNG-GAB;PECK, DONG-HYUN;YANG, TAE-HYUN
    • Transactions of the Korean hydrogen and new energy society
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    • v.11 no.1
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    • pp.19-27
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    • 2000
  • The polymer electrolyte membrane fuel cell (PEMFC) system was developed. In order to enhance the performance of membrane electrode assembly (MEA), the transfer printing method of the electrocatalyst layer on membrane was developed. The $H_2/O_2$ single cell with an electrode area of $50cm^2$ was fabricated and tested using 20 wt.% Pt/C as an electrocatalyst and the commercial and hand-made MEA such as Nafion 115, Hanwha, Dow, Flemion T and Gore Select. The 100-cell PEMFC stack with an active electrode area of $300cm^2$ was designed and fabricated using 40 wt.% Pt/C and 30 wt.% Pt-Ru/C as a cathode and anode electrocatalysts, respectively. The performance of PEMFC system was obtained to be 7kW (250A at 28V) and 3.5kW (70A at 50V) at $80^{\circ}C$ by flowing $H_2/air$ and methanol reformed fuel gas/air, respectively.

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Review on Facilitated Olefin Transport Membranes Utilizing Polymer Electrolytes and Polymer Nanocomposites (고분자 전해질과 고분자 나노복합체를 활용한 올레핀 촉진수송 분리막에 대한 총설)

  • Kang, Sang Wook
    • Membrane Journal
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    • v.26 no.3
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    • pp.173-178
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    • 2016
  • In this short review, the polymer electrolyte membranes consisting of polymer and Ag salts were introduced and various approaches to solve the long-term stability were summarized. In particular, utilizing $AgNO_3$ as carriers with ionic liquid, the replacement of polymer matrix as poly(ethylene phthalate) (PEP) for strong coordinative interactions with Ag ions and the introduction of $Al(NO_3)_3$ to $polymer/AgBF_4$ complexes were introduced for long-term stable facilitated olefin transport membranes. For the polymer nanocomposite membranes, the role of electron acceptors as polarizer on the surface of AgNPs and the approach to solve the low permeance were introduced.