• Title, Summary, Keyword: Proton conductivity

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Liquid uptake and Methanol Transport Behaviour of $PVdF/SPEEK/TiO_2$ Hybrid Membrane for DMFC (DMFC용 $PVdF/SPEEK/TiO_2$ 하이브리드 막의 수분함량과 메탄올 전이현상)

  • You, Sun-Kyung;Kim, Han-Joo;Kim, Young-Jae;Park, Soo-Gil
    • Proceedings of the KIEE Conference
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    • pp.194-196
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    • 2005
  • A series of inorganic-organic hybrid membranes were prepared with a systematic variation of titanium dioxidenanoparticles content. Their liquid uptake, methanol permeability and proton conductivity as a function of inoranic oxide content were investigated. The results obtained show that the inorganic oxide network decreases the proton conductivity and liquid uptake. It is also found that increase in inorganic oxide content leads to decrease of methanol permeability. In terms of the morphology, membranes are homogeneous and exhibit a good adhesion between inorganic domains and the polymer matrix. The properties of the composite membranes are compared with the standard nafion membrane.

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Preparation and Characterization of $TiO_2$Filled Sulfonated Poly(ether ether ketone) Nanocomposite Membranes for Direct Methanol Fuel Cells

  • Kim Han-Joo;Kalappa Prashantha;Son Won-Keun;Park Jong-Eun;Oshaka Tetsuya;Kim Hyun-Hoo;Hong Ji-Sook;Park Soo-Gil
    • KIEE International Transactions on Electrophysics and Applications
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    • v.5C no.4
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    • pp.165-170
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    • 2005
  • A series of inorganic-organic hybrid membranes were prepared with a systematic variation of titanium dioxide nanoparticle content. Their water uptake, methanol permeability and proton conductivity as a function of temperature were investigated. The results obtained show that the inorganic oxide network decreases the proton conductivity and water swelling. It is also found that increase in inorganic oxide content leads to decrease of methanol permeability. In terms of the morphology, membranes are homogeneous and exhibit good adhesion between inorganic domains and the polymer matrix. The properties of the composite membranes are compared with the standard nafion membrane.

Phase Formation and Electrical Conductivity of Ba-Doped LaBaGaO4 Layered Perovskite (Ba 첨가 LaBaGaO4 층상 Perovskite의 생성상과 전기전도도)

  • Lee, Kyu-Hyoung;Kim, Jong-Hwa;Kim, Hye-Lim;Kim, Shin;Lee, Hong-Lim
    • Journal of the Korean Ceramic Society
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    • v.41 no.8
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    • pp.623-627
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    • 2004
  • Phase formation and electrical conduction behavior of Ba-doped LaBaGa $O_4$ layered perovskite were studied. Orthorhombic single phase of $K_2$Ni $F_4$-type structure was observed for the composition range of 0$\leq$x$\leq$0.2 in the La$\_$1+x/Ba$\_$1+x/Ga $O_4$$\_$4-$\delta$/ system by X-ray analysis. In the dry atmosphere, La$\_$0.8/Ba$\_$1.2/Ga$\_$3.9/ exhibited mixed conduction of oxygen ion and hole (p-type) at high p( $O_2$). However, in water vapor containing atmosphere, it showed proton conduction due to the incorporation of water into oxygen vacancies. As the temperature decreased, the contribution of proton conductivity to the total conduction increased and proton conduction was dominant below 350$^{\circ}C$. The activation energy for proton conduction was calculated as 0.72 eV.

Phosphoric Acid-doped SDF-F/poly(VI-co-MPS)/PTFE Membrane for a High Temperature Proton Exchange Membrane Fuel Cell

  • Lee, Jong-Won;Yi, Cheol-Woo;Kim, Keon
    • 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.

Electrical Conductivity of YO$_{1.5}$-TaO$_{2.5}$-MgO Based Fluorite Phase (YO$_{1.5}$-TaO$_{2.5}$-MgO 계 Fluorite 상의 전기전도도)

  • Choi, Soon-Mok;Kim, Shin;Lee, Hong-Lim
    • Journal of the Korean Ceramic Society
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    • v.35 no.5
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    • pp.521-527
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    • 1998
  • Electrical conductivity of fluorite structure phases in the {{{{ {Y }_{0.8 } }}{{{{ { Ta}_{ 0.2} {O }_{1.7 }-MgO }} system has been studied. Electrical conductivity of 8mol% MgO doped {{{{ {Y }_{0.8 } }} {{{{ {Ta }_{0.2 } {O }_{1.7 } }} fluorite phase was lower than that of the undoped {{{{ {Y }_{0.8 } }}{{{{ {Ta }_{0.2 } {O }_{1.7 } }} When {{{{ { P}_{H2O } }} was increased electrical conductivity of {{{{ {Y }_{0.8 } }}{{{{ {Ta }_{0.2 } {O }_{1.7 } }} increased linealy with {{{{ { P}`_{H2O } ^{ {1 } over {2 } } }} The {{{{ {Y }_{0.8 } }}{{{{ {Ta }_{0.2 } {O }_{1.7 } }} fluorite phase exhibited higher electrical conductivity in wet atmosphere than in dry atmosphere. The identical trend was observed from the 8mol% MgO doped {{{{ {Y }_{0.8 } }}{{{{ {Ta }_{0.2 } {O }_{1.7 } }} fluorite phase.

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ORGANIC - INORGANIC COMPOSITE MEMBRANE FOR POLYMER ELECTROLYTE MEMBRANE FUEL CELL

  • Shul, Yong-Gun;Kim, Hyun-Jong;Ahn, Ji-Eun;Han, Hak-Soo
    • Proceedings of the Membrane Society of Korea Conference
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    • pp.37-40
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    • 2003
  • Mesoporous zeolite - heteropolyacid-polymer hybrid membrane was prepared by sol-gel processes to make a proton conducting membrane. The crystallinity of mesoporous zeolite in composite membrane was increased with contents of heteropolyacid. Proton conductivity obtained from impedance measurements increases with contents of heteropolyacid, about 10$^{-3}$ S/cm in ca. 1.5 Wt% heteropolyacid.

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Preparation and Characterizations of poly(arylene ether sulfone)/SiO2 Composite Membranes for Polymer Electrolyte Fuel Cell (고분자 전해질 연료전지(PEFC)용 poly(arylene ether sulfone)/SiO2 복합막의 제조 및 특성분석)

  • Shin, Mun-Sik;Kim, Da-Eun;Park, Jin-Soo
    • Membrane Journal
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    • v.27 no.2
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    • pp.182-188
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    • 2017
  • Sulfonated poly(arylene ether sulfone) (SPAES)-3-mercaptopropyl silica gel (3MPTSG) composite membranes with improved oxidative stability were prepared for polymer electrolyte fuel cell application. It has been reported that ether part of main chain of aromatic hydrocarbon based membranes were weak to radical attack to decrease membrane durability. In this study, the hydrophilic inorganic particles were introduced by minimizing a decrease in ion conductivity and increasing an oxidative stability. The composite membranes were investigated in terms of ionic conductivity, ion exchange capacity (IEC), FT-IR, TGA and contact angle, etc. As a result, increasing amount of the 3MPTSG resulted in decrease in proton conductivities and water uptakes at 100% R.H. but enhanced thermal and oxidative stabilities.

Preparation and Characterizations of Sulfonated Graphene Oxide (sGO)/Nafion Composite Membranes for Polymer Electrolyte Fuel Cells (고분자 전해질막 연료전지(PEMFCs)용 Sulfonated Graphene Oxide (sGO)/Nafion 복합막의 제조 및 특성분석)

  • Shin, Mun-Sik;Kang, Moon-Sung;Park, Jin-Soo
    • Membrane Journal
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    • v.27 no.1
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    • pp.53-59
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    • 2017
  • In this study, the composite membranes prepared by sulfonated graphene oxide (sGO) and Nafion were developed as proton exchange membranes (PEMs) for polymer electrolyte membrane fuel cells (PEMFCs). The sGO/Nafion composite membranes were prepared by mixing Nafion solution with the sGO dispersed in a binary solvent system to improve dispersity of sGO. The composite membranes were investigated in terms of ionic conductivity, ion exchange capacity (IEC), FT-IR, TGA and SEM, etc. As a result, the binary solvent system, i.e., ortho-dichlorobenzene (ODB) and N,N-dimethylacetamide (DMAc), were used to obtain high dispersion of sGO particles in Nafion solution, and the ionic conductivity of the sGO/Nafion composite membrane showed $0.06Scm^{-1}$ similar to other research results at lower water uptake, 11 wt%.

Stabilization of Covalently Cross-Linked SPEEK/Cs-Substituted HPA Composite Membranes for Water Electrolysis ($Cs^+$치환에 따른 수전해용 공유가교 SPEEK/HPA 복합막의 안정화)

  • Jee, Bong-Chul;Ha, Sung-In;Song, Min-Ah;Chung, Jang-Hoon;Moon, Sang-Bong;Kang, An-Soo
    • Transactions of the Korean hydrogen and new energy society
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    • v.22 no.1
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    • pp.1-12
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    • 2011
  • To improve the mechanical properties, such as durabilities and antioxidative characteristics, the covalently cross-linked (CL-) SPEEK (sulfonated polyether ether ketone)/Cs-substituted HPA (heteropoly acid) organic-inorganic composite membranes (CL-SPEEK/Cs-HPAs), have been intensively investigated. The composite membrane were prepared by blending cesium-substituted HPAs (Cs-HPAs), including tungstophosphoric acid (TPA), molybdophosphoric acid (MoPA), and tungstosilicic acid (TSiA) with cross-linking agent content of 0.01 mL. And composite electrolytes composed of Cs-HPAs, prepared by immersion (imm.) and titration (titr.) methods to increase the stability of HPAs in water, were applied to polymer electrolyte membrane electrolysis (PEME). As a result, the proton conductivity of Cs-substituted composite membranes increased rapidly over $60^{\circ}C$ but mechanical properties, such as tensile strength, decreased in accordance with added Cs content. The bleeding-out of Cs-TPA membranes by titration method (50 vol.% Cs) decreased steadily to 2.15%. In the oxidative stability test by Fenton solution, the durability of membranes with Cs-HPA significantly increased. In case of CL-SPEEK/ Cs-TPA membrane, duration time increased more than 1200 hours. It is expected that even though CL-SPEEK/Cs-MoPA membrane shows the high proton conductivity, electrocatalytic activity and cell voltage of 1.80 V for water electrolysis, the CL-SPEEK/Cs-TPA (imm.) is more suitable as an alternative membrane in real system with the satisfactory proton conductivity, mechanical properties, anti-oxidative stability and cell voltage of 1.89 V.

Fabrication and Characteristics of Partially Covalent-crosslinked Poly(arylene ether sulfone)s for Use in a Fuel Cell (고분자 전해질 연료전지용 부분 공유 가교된 술폰화 폴리아릴렌에테르술폰 막의 제조 및 특성)

  • Byun, Hong-Sik;Yoon, Kyung-Seok;Choi, Jong-Ho;Choi, Jun-Kyu;Hong, Sung-kwon;Hong, Young-Taik
    • Membrane Journal
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    • v.18 no.4
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    • pp.274-281
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    • 2008
  • Covalent-crosslinked sulfonated poly(arylene ether sulfone) (SPAES) copolymers were synthesized copolymerization technique and additionally crosslinked with divinylbenzene (DVB). To optimize the reaction condition, a concentration of crosslinking agent and a reaction time were varied in the ranges of $30{\sim}90\;v/v%$ and $30{\sim}720\;min$. The properties of the crosslinked membranes were investigated by SEM, TGA and the measurement of proton conductivity. It was found that the proton conductivity of crosslinked membranes decreased depending on a degree of crosslinking while water uptake and methanol permeability reduced.