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http://dx.doi.org/10.5229/JKES.2011.14.1.009

Effect of Annealing of Nafion Recast Membranes Containing Ionic Liquids  

Park, Jin-Soo (Department of Environmental Engineering, College of Engineering, Sangmyung University)
Shin, Mun-Sik (Department of Environmental Engineering, College of Engineering, Sangmyung University)
Sekhon, S.S. (Department of Applied Physics, Guru Nanak Dev University)
Choi, Young-Woo (Fuel Cell Research Center, New and Renewable Energy Research Division, Korea Institute of Energy Research (KIER))
Yang, Tae-Hyun (Fuel Cell Research Center, New and Renewable Energy Research Division, Korea Institute of Energy Research (KIER))
Publication Information
Journal of the Korean Electrochemical Society / v.14, no.1, 2011 , pp. 9-15 More about this Journal
Abstract
The composite membranes comprising of sulfonated polymers as matrix and ionic liquids as ion-conducting medium in replacement of water are studied to investigate the effect of annealing of the sulfonated polymers. The polymeric membranes are prepared on recast Nafion containing the ionic liquid, 1-ethyl-3-methylimidazolium tetrafluoroborate ($EMIBF_4$). The composite membranes are characterized by thermogravitational analyses, ion conductivity and small-angle X-ray scattering. The composite membranes annealed at $190^{\circ}C$ for 2 h after the fixed drying step showed better ionic conductivity, but no significant increase in thermal stability. The mean Bragg distance between the ionic clusters, which is reflected in the position of the ionomer peak (small-angle scattering maximum), is larger in the annealed composite membranes containing $EMIBF_4$ than the non-annealed ones. It might have been explained to be due to the different level of ion-clustering ability of the hydrophilic parts (i.e., sulfonic acid groups) in the non- and annealed polymer matrix. In addition, the ionic conductivity of the membranes shows higher for the annealed composite membranes containing $EMIBF_4$. It can be concluded that the annealing of the composite membranes containing ionic liquids due to an increase in ion-clustering ability is able to bring about the enhancement of ionic conductivity suitable for potential use in proton exchange membrane fuel cells (PEMFCs) at medium temperatures ($150-200^{\circ}C$) in the absence of external humidification.
Keywords
Annealing; High temperature proton exchange membrane fuel cell; Composite membrane; Ionic liquid; Proton conductivity;
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1 L. Rubatat, A. L. Rollet, G. Gebel, and O. Diat, ‘Evidence of Elongated Polymeric Aggregates in Nafion’ Macromolecules, 35, 4050 (2002).   DOI
2 L. Rubatat, A. L. Rollet, G. Gebel, and O. Diat, Fibrillar ‘Structure of Nafion: Matching Fourier and Real Space Studies of Corresponding Films and Solutions’ Macromolecules, 37, 7772 (2004).   DOI
3 C. R. M. R. B. Moore, ‘Chemical and morphological properties of solution-cast perfluorosulfonate ionomers, Macromolecules’ 21, 1334 (1988).   DOI   ScienceOn
4 G. Gebel, P. A. Aldebert, and M. Pineri, ‘Structure and related properties of solution cast perfluorosulfonated ionomer films’ Macromolecules, 20, 1425 (1987).   DOI
5 Y. H. Luan, Y. M. Zhang, H. Zhang, L. Li, H. Li, and Y. G. Liu, ‘Annealing effect of perfluorosulfonated ionomer membranes on proton conductivity and methanol permeability’ J. Appl. Polym. Sci., 107, 396 (2008).   DOI
6 Y. Woo, S. Y. Oh, Y. S. Kang, and B. Jung, ‘Synthesis and characterization of sulfonated polyimide membranes for direct methanol fuel cell’ J. Membr. Sci., 220, 31 (2003).   DOI
7 T. D. Gierke, G. E. Munn, and F. C. Wilson, ‘The morphology in nafion perfluorinated membrane products, as determined by wide- and small-angle x-ray studies’ J. Polym. Sci.: Polym. Phys. Ed., 19, 1687 (1981).   DOI
8 B. Dreyfus, G. Gebel, G. P. Aldebert, M. Pineri, and M. Escoubes, ‘Distribution of the in hydrated perfluorinated ionomer membranes from SANS experiments’ J. Phys. France, 51, 1341 (1990).   DOI
9 G. Gebel and J. Lambard, ‘Small-Angle Scattering Study of Water-Swollen Perfluorinated Ionomer Membranes’ Macromolecules, 30, 7914 (1997).   DOI
10 S. Kumar and M. Pineri, ‘Interpretation of small-angle xray and neutron scattering data for perfluorosulfonated ionomer membranes’ J. Polym. Sci. B., 24, 1767 (1986).   DOI
11 Q. Li, R. He, J. O. Jensen, and N. J. Bjerrum, ‘Approaches and Recent Development of Polymer Electrolyte Membranes for Fuel Cells Operating above $100{^{\circ}C}$’ J. Chem. Mater., 15, 4896-4915 (2003).   DOI
12 A. S. Ioselevich, A. A. Kornyshev, and J. H. G. Steinke, ‘Fine Morphology of Proton-Conducting Ionomers’ J. Phys. Chem. B., 108, 11953 (2004).   DOI
13 G. Gebel, ‘Structural evolution of water swollen perfluorosulfonated ionomers from dry membrane to solution’ Polymer, 41, 5829 (2000).   DOI
14 S. S. Sekhon, J.-S. Park, J.-S. Baek, S.-D. Yim, T.-H. Yang, and C.-S. Kim, ‘Small-angle X-ray scattering study of water free fuel cell membranes containing ionic liquids’ Chem. Mater., 22, 803 (2010).   DOI
15 J. Roziere and D. J. Jones, ‘Non-fluorinated polymer materials for proton exchange membrane fuel cells’ Annu. Rev. Mater. Res., 33, 503 (2003).   DOI
16 E. Cho, J.-S. Park, S. S. Sekhon, G.-G. Park, T.-H. Yang, W.-Y. Lee, C.-S. Kim and S.-B. Park, ‘A Study on Proton Conductivity of Composite Membranes with Various Ionic Liquids for High-Temperature Anhydrous Fuel Cells’ J. Electrochem. Soc., 156, B197 (2009).   DOI
17 S. S. Sekhon, J.-S. Park, and Y.-W Choi, ‘A SAXS study on nanostructure evolution in water free membranes containing ionic liquid: from dry membrane to saturation’ Phys. Chem. Chem. Phys., 12, 13763 (2010).   DOI   ScienceOn
18 S. S. Sekhon, J.-S. Park, E. Cho. Y.-G. Yoon, C.-S. Kim, and W.-Y. Lee, ‘Morphology studies of high temperature proton conducting membranes containing hydrophilic/hydrophobicionic liquids’ Macromolecules, 42, 2054 (2009).   DOI
19 J.-S. Baek, J.-S Park, S. S. Sekhon, T.-H. Yang, Y.-G. Shul, and J.-H. Choi, ‘Preparation and characterization of nonaqueous proton-conducting membranes with the low content of ionic liquids’ Fuel Cells, 10, 762 (2010).   DOI
20 J. Li, X. Yang, H. Tang, and M. Pan, ‘Durable and high performance Nafion membrane prepared through hightemperature annealing methodology’ J. Membr. Sci., 361, 38 (2010).   DOI
21 C. R. M Robert and B. Moore, ‘Procedure for preparing solution-cast perfluorosulfonate ionomer films and membranes’ Anal. Chem., 58, 2570 (1986).   DOI