Membrane Journal (멤브레인)

The Membrane Society of Korea (한국막학회)
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Sulfonated Polystyrene/PTFE Composite Membranes for Direct Methanol Fuel Cell

직접 메탄올 연료전지를 위한 술폰화 폴리스티렌/테플론 복합막 제조 및 특성연구

  • 김정훈 (한국화학연구원 화학기술연구부) ;
  • 신정필 (한국화학연구원 화학기술연구) ;
  • 박인준 (한국화학연구원 화학기술연구) ;
  • 이수복 (한국화학연구원 화학기술연구) ;
  • 서동학 (한앙대학교 화학공학과)
  • Published : 2004.06.01
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Abstract

For the application of direct methanol fuel cell (DMFC), sulfonated polystyrene/teflon (PS/PTFE) composite membranes were developed by changing monomer ratio of styrene and DVB. The composite membranes were prepared as follows: first, the monomer mixtures consisting of styrene, divinyl benzene and AIBN were impregnated in porous PTFE film and then, polymerized under 8$0^{\circ}C$ to give PS/PTFE membranes. Finally, the membranes were reacted with chlorosulfonic acid in 1,2-dichloroethane to give the sulfonated composite membranes. The measurements of ATR-FTIR, SEM, solvent uptake test and ion exchange capacity (IEC) were done for the resulting membranes before or after sulfonation, respectively, which showed the composite membranes with proper crosslinking degree and sulfonic acid content were prepared well as a function of styrene/DVB ratio. ion conductivity and methanol permeability were studied for the sulfonated membranes. It was found that with decreasing the ratio of styrene/DVB, methanol permeability decreased from $6.6{\times}10^{-7}∼1.3{\timas}10^{-7}$ $\textrm{cm}^2$/s, which are much lower values than that of Nafion$^{(R)}$117($1.02{\times}10^{-6}$ $\textrm{cm}^2$/s). Under the same monomer condition, ion conductivity decreased from 0.11 S/cm ($25^{\circ}C$) to 0.08 S/cm ($25^{\circ}C$), which are similar or a little higher values compared with $Nafion^{(R)}117 (1.02{\times}10^{-6}$ $\textrm{cm}^2$/s, 0.0824 S/cm). These two results confirmed the composite membranes prepared could be applied successfully to DMFC.C.

술폰화 폴리스티렌/테플론(Polystyrene/Teflon, 이하 'PS/PTFE'로 칭함) 복합막을 제조하여 직접 메탄을 연료전지용 막에 관한 특성을 조사하였다. 복합막은 다음과 같이 제조되었다. 먼저 다공성 테플론 필름에 styrene 단량체와 가교제인 diviny benzene (이하 'DVB'로 칭함)의 비율을 달리하면서, 개시제 2,2'-azobis(isobutylonitlie) (AIBN)와 함께 함침시킨 후 열을 가해 폴리스티렌/테플론 복합막을 제조하였다. 그 후 술폰화제인 chlorosulfonic acid와 1,2-dichloroethane혼합용액을 사용하여 술폰화된 복합막을 제조하였다. 제조된 복합막의 술폰화 전과 후의 물리화학적 구조는 ATR-FTIR, SEM, THF 및 물에 대한 함유율, 이들의 이온교환량을 통하여 확인하였다. 이러한 결과로부터 스티렌/디비닐벤젠의 비율에 따라 복합막이 성공적으로 제조되었음을 확인하였다. 또한 가교제인 디비닐벤젠의 함량이 높을수록, 가교도가 증가하여 물 및 THF에 대한 함유율이 감소하였다. 이온전도도, 메탄올투과도를 조사한 결과, 디비닐벤젠의 함량 증가와 함께 이온전도도는 감소하였으며, 메탄올 투과도가 감소하였다. 제조된 술폰화된 폴리스티렌/테플론 복합막은 Nafion$^{(R)}$ 과 비교할 만한 높은 이온 전도도(0.11∼0.08 S/cm, $25^{\circ}C$)를 보이면서 훨씬 낮은 메탄올 투과도($6.6{\times}10^{-7}∼1.3{\timas}10^{-7}$ $\textrm{cm}^2$/s)를 나타내었다. 이러한 결과들은 본 연구에서 개발된 복합막이 직접 메탄올 연료전지에 적용될 가능성이 높다는 것을 보여준다.

Keywords

References

  1. Macromolecules v.13 Ion percolation and insulator-to-conductor transition in Nafion perfluorosulfonic acid membranes W.Y.Hsu;J.R.Barkley;P.Meakin https://doi.org/10.1021/ma60073a041
  2. J. Membr. Sci. v.16 Electrochemical behavior of Nafion type membrane G.Scibona;C.Fabiani;B.Scuppa https://doi.org/10.1016/S0376-7388(00)81298-3
  3. Mod. Aspects Electrochem. v.16 Structural and transport properties of perfluorinated ion-exchange membrane R.S.Yeo,H.L.Yeager
  4. J. Membr. Sci. v.32 Temperature dependence of water content and proton conductivity in polyperfluorosulfonic acid membranes P.C.Rieke;N.E.Vanderborgh https://doi.org/10.1016/S0376-7388(00)85014-0
  5. J. Membr. Sci. v.143 The rate of isothermal hydration of polyperfluorosulfonic acid membranes T.V.Nguyen;N.Vanderborgh https://doi.org/10.1016/S0376-7388(98)00030-1
  6. J. Electrochem. Soc. v.142 C.Pu;W.Huang;K.L.Ley;E.S.Smotkin https://doi.org/10.1149/1.2044333
  7. Catal. Today G.T.Burstein;C.J.Barnett;A.R.Kucernak;K.R.Williams
  8. US Patent no. 5,422,411 J.Wei;C.Stone;A.E.Steck
  9. J. Membr. Sci. v.185 on the development of proton conducting polymers membranes for hydrogen and methanol fuel cells K.D.Kreuer https://doi.org/10.1016/S0376-7388(00)00632-3
  10. Macromolecules v.33 Miscibility behavior of polybenzimidazole/sulfonated polysulfone blends for use in fuel cell applications V.Deimede;G.A.Voyiatzis;J.K.Kallitsis;L.Qingfeng;N.J.Bjerrum https://doi.org/10.1021/ma000165s
  11. Electrochimica Acta v.46 New polymer electrolytes based on blends of sulfonated polysulfones with polybenzimidazole C.Hasiotis;V.Deimede;C.Kontoyannis https://doi.org/10.1016/S0013-4686(01)00437-6
  12. J. Membr. Sci. v.209 Effect of conditioning techniques of perfluorinated sulphocationic membranes on their hydrophylic and electrotransport properties N.P.Berezina;S.V.Timofeev;N.A.Kononenko https://doi.org/10.1016/S0376-7388(02)00368-X
  13. J. Power Sources v.117 Chemically-modified Nafion$^R$/poly(vinylidene fluoride) blend ionomers for proton exchange membrane fuel cells M.K.Song;Y.T.Kim;J.M.Fenton;H.R.Kunz;H.W.Rhee https://doi.org/10.1016/S0378-7753(03)00166-6
  14. J. Phys. Chem. v.B 108 Effect of Redox State of Pt-Ru Electrocatalysts on Methanol Oxidation Activity A.H.C.Sirk;J.M.Hill;S.K.Y.Kung;V.I.Birss
  15. Korean J. Chem. Eng. v.19 no.3 Performance improvement of electrode for polymer electrolyte membrane fuel cell T.Yang;G.G.Park;P.Pugazhendhi;W.Y.Lee;C.S.Kim https://doi.org/10.1007/BF02697149
  16. J. Membr. Sci. v.185 Ulrich Stimming, Proton conducting membranes based on electrolyte filled microporous matrices Stefan Haufe https://doi.org/10.1016/S0376-7388(00)00637-2
  17. J. Am. Chem. Soc. v.123 Synthesis of poly(styrene sulfonate) brushes Y.Tran;P.Auroy
  18. J. Electrochem. Soc. v.145 Proton and methanol transport in poly(perfluorosulfonate) membranes containing ${Cs}^+$ and $H^+$ cations V.Tricoli https://doi.org/10.1149/1.1838876
  19. Membr. J. v.11 no.3 Preparation of pore-filled ion-exchange membranes using poly(vinylbenzyl ammoninum salt) H.S.Byum
  20. 한남대학교 석사학위 논문, 膜學實驗法 폴리비닐알콜을 이용한 직접메탄을 열료전지용 이온교환막 제조에 관한 연구 전지현;임지원;中垣正幸
  21. J. Membr. Sci. v.220 Sulfonated polystyrene grafted polypropylene composite electrolyte membranes for direct methanol fuel cells B.Bae;D.Kim https://doi.org/10.1016/S0376-7388(03)00216-3
  22. J. Membr. Sci. v.220 Synthesis and characterization of sulfonated polyimide membranes for direct methanol fuel cell Y.Woo;S.Y.Oh;Y.S.Kang;B.Jung https://doi.org/10.1016/S0376-7388(03)00185-6
  23. J. Mater. Electrochem Syst. v.3 Preparation, characterization, and fuel cell application of new acid-base blend membranes J. Kerres;A.Ullrich;T.Haring;Preidel;M.Baldauf;U.Gebhardt