• Title/Summary/Keyword: methanol permeability

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Characterization of Polymer Blends of Poly(ether sulfone)/Sulfonated Poly(ether ether ketone) for DMFC (직접메탄올 연료전지용 Poly(ether sulfone)/Sulfonated Poly(ether ether ketone) 블렌드 막의 특성 연구)

  • Cheon, Hun Sang;Lee, Choong Gon;Hong, Seong Uk
    • Applied Chemistry for Engineering
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    • v.16 no.1
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    • pp.144-149
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    • 2005
  • Sulfonated poly(ether ether ketone) (SPEEK) was blended with poly(ether sulfone) (PES) at various compositions. To investigate the possibility of using the blend membranes as polymer electrolyte membranes for direct methanol fuel cell, the blend membranes were characterized in terms of methanol permeability, proton conductivity, ion exchange capacity, and water content. Both proton conductivity and methanol permeability of SPEEK were relatively high. As the amount of PES increased, methanol permeability decreased more rapidly compared to proton conductivity. The experimental results indicated that the blend membrane with 40 wt% PES was the best choice in terms of the ratio of proton conductivity to methanol permeability.

Proton Conductivity and Methanol Permeability of Sulfonated Polysulfone/PPSQ Composite Polymer Electrolyte Membrane (설폰화된 폴리설폰/PPSQ 유-무기 복합 전해질막의 수소이온 전도도 및 메탄올 투과 특성)

  • Kwon Jeongdon;Lee Changjin;Kang Yongku
    • Journal of the Korean Electrochemical Society
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    • v.7 no.2
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    • pp.89-93
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    • 2004
  • Sulfonated polysulfone (SPSF) with poly(phenylmethyl silsesquioxane, PPSQ) composite polymer electrolyte membranes were prepared and their proton conductivity, water uptake and methanol permeability of membranes were characterized. By controlling the ratio of $(CH_3)_3SCI\;and\;CISO_3H$ and reaction time, SPSF with $37\~75\%$ degree of sulfonation were synthesized. The increase of sulfonate groups in the base polymer resulted in the increase of the water uptake in the membranes as well as methanol permeability. Composite membranes were prepared by casting of DMF solution of SPSF and PPSQ. The proton conductivity of the composite membrane at room temperature was $2.8\times10^{-3}\~4.9\times10^{-2}S/cm.$ The increase of PPSQ contents in composite membranes resulted in a decrease in water uptake and methanol permeability. Composite membranes containing $5\%$ PPSQ did not make a significant effect on the proton conductivity nO methanol permeability compared with that of pristine SPSF, but a significant decrease of water uptake was observed.

Preparation and Their Characterization of Blended Polymer Electrolyte Membranes of Polysulfone and Sulfonated Poly(ether ether ketone) (Polysulfone/SPEEK 블랜드 고분자 전해질 막 제조 및 특성 연구)

  • Cheon, Hun-Sang;Oh, Min;Hong, Seong-Uk
    • Membrane Journal
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    • v.13 no.1
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    • pp.47-53
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    • 2003
  • Poly(ether ether ketone)(PEEK) was sulfonated using sulfuric acid and blended with polysulfone with various ratios. The blended polymer electrolyte membranes were characterized in terms of methanol permeability, proton conductivity and ion exchange capacity. As the amount of sulfonated PEEK increased, both methanol permeability and proton conductivity increased. This was due to the increase of ion exchange capacity. The experimental results indicated that the blend membrane with 20% polysulfone was the best choice In terms of the ratio of proton conductivity to methanol permeability.

Synthesis and Characterization of Sulfonated Poly(phthalazinone ether sulfone)(sPPES)/Silica Membrane for Proton Exchange Membrane Materials

  • Kim, Dae Sik;Park, Ho Bum;Nam, Sang Young;Rhim, Ji Won;Lee, Young Moo
    • Korean Membrane Journal
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    • v.6 no.1
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    • pp.44-54
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    • 2004
  • Organic-inorganic composite membranes based on sulfonated poly(phthalazinone ether sulfone) (sPPES)/silica hybrid were prepared using the sol-gel process under acidic conditions. The sulfonation of PPES with concentrated sulfuric acid as sulfonation agent was carried out to prepare proton exchange membrane material. The behaviors of the proton conductivity and methanol permeability are depended on the sulfonation time (5-100 hr). The hybrid membranes composed of highly sulfonated PPES (IEC value: 1.42 meq./g) and silica were fabricated from different silica content (5-20 wt%) in order to achieve desirable proton conductivity and methanol permeability demanded for fuel cell applications. The silica particles within membranes were used for the purpose of blocking excessive methanol cross-over and for forming the path way to transport of the proton due to absorbing water molecules with ≡SiOH on silica. The presence of silica particles in the organic polymer matrix results in hybrid membranes with reduced methanol permeability and improved proton conductivity.

Preparation and Characterization of Sulfonated Poly(phthalazinone ether sulfone ketone) (SPPESK)/Silica Hybrid Membranes for Direct Methanol Fuel Cell Applications

  • Kim, Dae-Sik;Shin, Kwang-Ho;Park, Ho-Bum;Lee, Young-Moo
    • Macromolecular Research
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    • v.12 no.4
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    • pp.413-421
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    • 2004
  • Sulfonated poly(phthalazinone ether sulfone ketone) (SPPESK) membranes and sol-gel derived SPPESK/silica hybrid membranes have been investigated as potential polymer electrolyte membranes for direct methanol fuel cell (DMFC) applications. In comparison with the SPPESK membrane, the SPPESK/silica membranes exhibited higher water content, improved proton conductivity, and lower methanol permeability. Notably, the silica embedded in the membrane acted as a material for reducing the fraction of free water and as a barrier for methanol transport through the membrane. From the results of proton conductivity and methanol permeability studies, we suggest that the fractions of bound and free water should be optimized to obtain desirable proton conductivities and methanol permeabilities. The highly sulfonated PPESK hybrid membrane (HSP-Si) displayed higher proton conductivity (3.42 ${\times}$ 10$^2$ S/cm) and lower methanol permeability (4.15 ${\times}$ 10$\^$7/ $\textrm{cm}^2$/s) than those of Nafion 117 (2.54 ${\times}$ 10$^2$ S/cm; 2.36 ${\times}$ 10$\^$6/ $\textrm{cm}^2$/s, respectively) at 30$^{\circ}C$. This characteristic of the SPPESK/silica membranes is desirable for future applications related to DMFCs.

Molecular Structure of Poly(phenylene oxide-g-styrenesulfonic acid) and the Conductivity and Methanol Permeability of the Membrane

  • Cho, Chang-Gi;You, Young-Gyu;Jang, Hye-Young
    • Proceedings of the Polymer Society of Korea Conference
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    • 2006.10a
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    • pp.269-269
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    • 2006
  • The molecular structure of poly(2,6-dimethyl-4,4' -phenylene oxide)-g-poly (styrenesulfonic acid) (PPO-g-PSSA) graft copolymer was designed, and synthesized via living radical polymerization. Obtained graft copolymers were transformed into proton exchange membranes for direct methanol fuel cell (DMFC) application. The performance of the membranes was measured in terms of water uptake, proton conductivity, methanol permeability, and thermal stability. Very low methanol permeability and good proton conductivity were observed by adjusting grafting frequency and PSSA block content.

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Nafion-Sulfonated Poly(arylene ether sulfone) Composite Membrane for Direct Methanol Fuel Cell

  • Choi Jisu;Kim II Tae;Kim Sung Chul;Hong Young Taik
    • Macromolecular Research
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    • v.13 no.6
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    • pp.514-520
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    • 2005
  • Composite membranes of Nafion and sulfonated poly(arylene ether sulfone) were prepared. Sulfonated poly(arylene ether sulfone)s with different degrees of sulfonation were blended with Nafion to reduce the methanol crossover. The morphology, proton conductivity and methanol permeability of the resulting composite membranes were investigated by SEM, EDAX, AC impedance spectroscopy and permeability measuring instrument. The cross­sections of the composite membranes showed a phase separated morphology. The morphology and phase separation mechanism could be controlled by varying the blend ratio and the degree of sulfonation of poly(arylene ether sulfone). These complex morphologies can be applied for reducing methanol crossover. The methanol permeability and proton conductivity of the composite membranes were lower than those of Nafion 117 membrane since the development of an ionic pathway in the blend membrane was more difficult than that in Nafion itself.

Studies on the Addition of the Hydroquinonesulfonic Acid to Poly(vinyl alcohol)/poly(acrylic acid-co-maleic acid) Membranes to Improve the Ion Conductivity for Fuel Cell Applications (Poly(vinyl alcohol)/poly(acrylic acid-co-maleic acid) 이온교환막에 이온전도도 향상을 hydroquinonesulfonic acid 첨가 연구)

  • 임지원;황호상
    • Membrane Journal
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    • v.14 no.1
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    • pp.44-52
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    • 2004
  • This paper concerns the development of a cationic polymeric membranes for direct methanol fuel cell. The crosslinked poly(vinyl alcohol) (PVA) membranes with poly(acrylic acid-co-maleic acid) (PAM) and hydroquinonesulfonic acid (HQSA) as the crosslinking agents were prepared according to the amount of crosslinking agents. The resulting membranes were characterized in terms of methanol permeability, proton conductivity, water content and ion exchange capacity. The methanol permeability and proton conductivity increased with increasing PAM content up to 9 wt% and then decreased. This trend is considered the effect of the cross linking rather than the introduction of hydrophilic groups. When the HQSA contents were varied, no interesting increases of proton conductivity, water content and ion exchange capacity were found.

Titanium Dioxide Nanoparticles filled Sulfonated Poly(ether ether ketone) Proton Conducting Nanocomposites Membranes for Fuel Cell

  • Kalappa, Prashantha;Hong, Chang-Eui;Kim, Sung-Kwan;Lee, Joong-Hee
    • Proceedings of the Korean Society For Composite Materials Conference
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    • 2005.11a
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    • pp.87-90
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    • 2005
  • This paper presents an evaluation of the effect of titanium dioxide nanoparticles in sulfonated poly(ether ether ketone) (SPEEK) with sulfonation degree of 57%. A series of inorganic-organic hybrid membranes were prepared with a systematic variation of titanium dioxide nanoparticles 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 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 standard nafion membrane.

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Proton Conductivity and Methanol Permeability of Sulfonated Poly(aryl ether sulfone)/Modified Graphene Hybrid Membranes (술폰화 폴리아릴렌에테르술폰/개질된 그라핀 복합막의 이온전도도 및 메탄올 투과도)

  • Huh, Hoon;Kim, Deuk-Ju;Nam, Sang-Yong
    • Membrane Journal
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    • v.21 no.3
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    • pp.247-255
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    • 2011
  • In this study, to obtain good dispersity of graphene which has excellent conductivity and mechanical strength, the graphene was modified by two different methods. Then the SPAES/graphene hybrid membranes were fabricated from different graphene contents. We compared performance of composite membrane with different preparing method of graphene and content of modified graphene. The morphology of the composite membranes has been investigated using SEM. Chemical structure of modified graphene was analyzed using by FT-IR and EDX. The proton conductivity and methanol permeability of the hybrid membranes were studied with changing graphene content from 0.5 to 3.0 wt.%. The SPAES/modified graphene composite membranes showed high proton conductivity (0.21 S/cm) compared with the SPAES membrane (0.09 S/cm) at $80^{\circ}C$ and 100% relative humidity condition. And the methanol permeability was decreased linearly as the content of modified graphene increased from 0 to 1.5 wt%.