• Title, Summary, Keyword: Proton conductivity

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Phase Formation and Protoniz Conduction of La(Ba)$ScO_3$ Perovskites (La(Ba)$ScO_3$계 Perovskite의 생성상 및 Proton 전도)

  • Lee, Kyu-Hyoung;Kim, Hyu-Lim;Kim, Shin;Lee, Hyung-Jik;Lee, Hong-Lim
    • Journal of the Korean Ceramic Society
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    • v.38 no.11
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    • pp.993-999
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    • 2001
  • Phase formation and proton conduction in BaO doped LaSc $O_3$with perovskite structure were studied. L $a_{0.6}$B $a_{0.4}$Sc $O_{2.8}$, viz. 40at% $Ba^{2+}$ ion doped composition, showed a single cubic phase, while the other compositions doped less than 30 at% $Ba^{2+}$ ion showed the cubic phase and the orthorhombic one. Above $650^{\circ}C$ oxygen ion conduction was dominant in $N_2$atmosphere and below this temperature proton conduction was observed in wet atmosphere. All compositions were found to be the pure proton conductors below 30$0^{\circ}C$. The proton conductivity (bulk) of L $a_{0.6}$B $a_{0.4}$Sc $O_{2.8}$ was higher than those of any other composition.osition.ion.

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Silica/polymer Nanocomposite Containing High Silica Nanoparticle Content : Change in Proton Conduction and Water Swelling with Surface Property of Silica Nanoparticles (고농도의 Silica Nanoparticle을 함유한 Silica/polymer 나노복합체 : 실리카 표면 특성에 따른 수소이온 전도성 및 수팽윤도 변화)

  • Kim, Ju-Young;Kim, Seung-Jin;Na, Jae-Sik
    • Applied Chemistry for Engineering
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    • v.21 no.5
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    • pp.514-521
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    • 2010
  • A new one-shot process was employed to fabricate proton exchange membranes (PEMs) over conventional solvent-casting process. Here, PEMs containing nano-dispersed silica nanoparticles were fabricated using one-shot process similar to the bulk-molding compounds (BMC). Different components such as reactive dispersant, urethane acrylate nonionmer (UAN), styrene, styrene sulfuric acid and silica nano particles were dissolved in a single solvent dimethyl sulfoxide (DMSO) followed by copolymerization within a mold in the presence of radical initiator. We have successfully studied the water-swelling and proton conductivity of obtained nanocomposite membranes which are strongly depended on the surface property of dispersed silica nano particles. In case of dispersion of hydrophilic silica nanoparticles, the nanocomposite membranes exhibited an increase in water-swelling and a decrease in methanol permeability with almost unchanged proton conductivity compared to neat polymeric membrane. The reverse observations were achieved for hydrophobic silica nanoparticles. Hence, hydrophilic and hydrophobic silica nanoparticles were effectively dispersed in hydrophilic and hydrophobic medium respectively. Hydrophobic silica nanoparticles dispersed in hydrophobic domains of PEMs largely suppressed swelling of hydrophilic domains by absorbing water without interrupting proton conduction occurred in hydrophilic membrane. Consequently, proton conductivity and water-swelling could be freely controlled by simply dispersing silica nanopartilces within the membrane.

Effects of proton beam irradiation on the solid oxide electrolyte

  • Cho, Won-Je;Lee, Il-Seop;Kim, Tae-Hyung;Ryu, Boo-Hyung;Lee, In-Ja
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • pp.446-446
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    • 2008
  • The effects of proton beam irradiation on the yittria-stabilized zirconia (YSZ) pellets have been investigated using SEM, EDX and TGA. 130 keV proton beam was irradiated on YSZ with high doses and annealed at various temperatures. The ion conductivity was also measured as a function of proton irradiation temperature and annealing temperature and the results were compared with their corresponding SEM images and the results of SRIM calculations.

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Thermal and Electrical Properties of Poly(vinylidene fluoride-hexafluoropropylener)-Based Proton Conducting Gel-Electrolytes (Poly(vinylidene fluoride-hexafluoropropylene)계 양성자 전도성 겔-전해질의 열적, 전기적 특성)

  • 최병구;박상희
    • Polymer Korea
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    • v.26 no.2
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    • pp.179-184
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    • 2002
  • Polymer electrolyte films consisting of poly (vinylidenefluoride-hexafluoro-propylene) (PVdF-HFP) $H_3PO_4$and a mixture of ethylene carbonate(EC), $\gamma$-butyrolactone(BL) and dimethylcarbonate (DMC) were examined in order to obtain the best compromise between high protonic conductivity, homogeniety and dimensional stability. Measurements of differential scanning calorimetry and ionic conductivity have been carried out for various compositions. The highest proton conductivity of 7.3 $\times$$10^{-3}Sm^{-1}$ at $30^{\circ}C$ were obtained for a film of 30(PVdF-HFP) + 50EC/DMC + 20H$_3$PO$_4$. From the thermal study, it has been found that the PVdF-HFP gels are stable up to $80^{\circ}C$, and the $H_3PO_4$ enhances the miscibility of the polymer and the solvent by interacting sensitively with polymer segments.

Preparation and Characterization of Ion-exchange Membrane Using sPEEK for Fuel Cell Application (Sulfonated-PEEK를 이용한 연료전지용 이온교환막의 제조 및 특성평가)

  • Jang, Won-Gi;Ye, Se-Hui;Kang, Seung-Kyu;Kim, Ji-Tae;Byun, Hong-Sik
    • Membrane Journal
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    • v.21 no.3
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    • pp.270-276
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    • 2011
  • A nascent membrane was prepared by using the solution evaporation method with a solution of sPEEK, EdAn (cross-linking reagent), and PEA (grafting reagent) in DMAc. Then, after the imination and sulfonation process the cross-linked and grafted ion-exchange membrane, CG-sPEEK, was obtained. The sulfonation and imination reactions were confirmed by FTIR analysis. In order to evaluate the possibility of prepared membrane for the use of an ion-exchange membrane in PEMFC, proton conductivity, water uptake and volume change were measured and compared with a commercial membrane, Nafion 115. It was revealed that since the proton conductivity (0.17 S/cm) of prepared membrane were much higher than those of Nafion 115 (0.10 S/cm) the prepared membrane could be used for the ion-exchange membrane in PEMFC. However, the high water uptake (130%) of CG-sPEEK should be reduced for the dimension stability.

Electrical Characteristics of BaCe$_{0.9}$R$_{0.1}$O$_3$-$\delta$(R=La, Yb, Al) Based Perovskite Phase (BaCe$_{0.9}$R$_{0.1}$O$_3$-$\delta$(R=La, Yb, Al)계 페롭스카이트 상의 전기적 특성)

  • Choi, Soon-Mok;Kim, Shin;Lee, Hong-Lim
    • Journal of the Korean Ceramic Society
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    • v.36 no.1
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    • pp.69-76
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    • 1999
  • Electrical characteristics of perovskite phases in the BaCe0.9R0.1O3-$\delta$(R=La, Yb and Al) system have been studied. Electrical conductivities of all specimens in air were higher than those in N2 atmosphers between 600 and 100$0^{\circ}C$. When temperature was elevated, the electrical conductivity difference between both atmospheres increased. Electrical conductivity of Yb3+ doped BaCeO3 specimen was higher than those of the La3+ and Al3+ doped specimens. The BaCe0.0Al0.1O3-$\delta$ showed higher proton transference number than both BaCe0.9Yb0.1O3-$\delta$ and BaCe0.9La0.1O3-$\delta$.

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Development and Characterization of Polymer Electrolyte Membranes Containing Polysilsesquioxane Spheres (Polysilsesquioxane 구를 함유하는 고분자 전해질 막 제조 및 특성 연구)

  • Hong Seong Uk;Cheon Hun Sang;Kim Young Baik;Park Hun Hwee
    • Membrane Journal
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    • v.15 no.1
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    • pp.1-7
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    • 2005
  • Polymer electrolyte membranes containing polysilsesquioxane (PSQ) spheres were prepared with the blend of sulfonated poly(ether ether ketone) (SPEEK) (60%) and poly(ether sulfone) (PES) (40%). The amount of PSQ spheres was fixed at 10 wt%. The prepared polymer electrolyte membranes were characterized in terms of methanol permeability, proton conductivity, and ion exchange capacity. In all cases, both methanol permeability and proton conductivity of the polymer electrolyte membranes containing PSQ spheres were lower than the values of Nafion 117 and higher than those of SPEEK/PES (6:4) blend without PSQ spheres. The experimental results indicated that the polymer electrolyte membranes containing MS64 and VTMOS spheres were the best choice in terms of the ratio of proton conductivity to methanol permeability.

Characterization of SPAES Composite Membrane Using Silane Based Inorganics (실란계 복합화 무기물을 이용한 SPAES 복합막의 특성평가)

  • Woo, Chang Hwa;Kim, Deuk Ju;Nam, Sang Yong
    • Membrane Journal
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    • v.25 no.5
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    • pp.456-463
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    • 2015
  • In this study, we synthesize novel silane based inorganics for preparation of the polymer electrolyte membrane with high proton conductivity under high temperature condition and developed membranes are characterized. SPAES, hydrocarbon based polymer are synthesized and used as main polymeric material. We used sol-gel method to prepare inorganic material with high performance using silica, phosphate and zirconium. Three types of inorganics were prepared by control of the mole ration of each component. As a result of EDX analysis, the inorganic materials are well dispersed in the polymer membrane. The water uptake of the composite membrane is increased by introduction of the hydrophilic inorganic material in the membrane. When the content of the zirconium in the membrane is increased, the proton conductivity of the composite membrane shows the higher value than pure SPAES membrane at the high temperature. And the silica based inorganics effect to increase the proton conductivity under low temperature condition.

Development of Polymer Electrolyte Membranes Using Dipole-dipole Interaction for Fuel Cell Applications (쌍극자-쌍극자 상호작용 형성을 이용한 향상된 기능의 연료전지용 고분자 전해질 막의 개발)

  • Won, Mihee;Kwon, Sohyun;Kim, Tae-Hyun
    • Journal of the Korean Chemical Society
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    • v.59 no.5
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    • pp.413-422
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    • 2015
  • Proton exchange membrane (PEM), which transfers proton from the anode to the cathode, is the key component of the proton exchange membrane fuel cell (PEMFC). Nafion is widely used as PEM due to its high proton conductivity as well as excellent chemical and physical stabilities. However, its high cost and the environmental hazards limit the commercial application in PEMFCs. To overcome these disadvantages, various alternative polymer electrolytes have been investigated for fuel cell applications. We used densely sulfonated polymers to maximize the ion conductivity of the corresponding membrane. To overcome high swelling, dipole-dipole interaction was used by introducing nitrile groups into the polymer backbone. As a result, physically-crosslinked membranes showed improved swelling ratio despite of high water uptake. All the membranes with different hydrophilic-hydrophobic compositions showed higher conductivity, despite their lower IEC, than that of Nafion-117.