Preparation and Gas Permeability Measurements of PVDF-HFP/Ionic Liquid Gel Membranes

PVDF-HFP/이온성 액체 겔 분리막 제조 및 기체 투과도 측정

  • Ko, Youngdeok (Department of Chemical and Biological Engineering, Hanbat National University) ;
  • Park, Doohwan (Green House Gas Research Center, Korea Institute of Energy Research) ;
  • Baek, Ilhyun (Green House Gas Research Center, Korea Institute of Energy Research) ;
  • Hong, Seong Uk (Department of Chemical and Biological Engineering, Hanbat National University)
  • 고영덕 (한밭대학교 화학생명공학과) ;
  • 박두환 (한국에너지기술연구원 온실가스연구실) ;
  • 백일현 (한국에너지기술연구원 온실가스연구실) ;
  • 홍성욱 (한밭대학교 화학생명공학과)
  • Received : 2014.05.12
  • Accepted : 2014.09.15
  • Published : 2014.12.10


It is well known that $CO_2$ can be dissolved easily in imidazolium-based room temperature ionic liquids (RTILs). Because of the high $CO_2$ solubility in RTILs, membranes containing RTILs can separate easily gas mixtures such as $CO_2/N_2$ and $CO_2/CH_4$. In this study, we prepared poly(vinylidene fluoride)-hexafluoropropyl copolymer (PVDF-HFP) gel membranes with several RTILs and measured permeabilities of several gases. When the anion of ionic liquids was tetrafluoroborate($BF{_4}^-$), both $CO_2$ permeability and selectivities decreased as the carbon number of the cation increased. When the cation of ionic liquids was 1-ethyl-3-methylimidazolium[emim], $CO_2$ permeability of gel membranes containing bis(trifluoromethane) sulfoneimide($Tf_2N^-$) anion was double compared to those containing tetrafluoroborate($BF{_4}^-$) anion. However, $CO_2/N_2$ and $CO_2/CH_4$ selectivities of the $Tf_2N^-$ case were decreased, whereas the $H_2$ selectivity was almost the same for two cases.


Gas permeability;PVDF-HFP;ionic liquid;carbon dioxide


  1. L. M. Robeson, The Upper Bound Revisited, J. Membr. Sci., 320, 390-400 (2008).
  2. J. M. S. Henis and M. K. Tripodi, The Developing Technology of Gas Separating Membranes, Science, 220, 11-17 (1983).
  3. P. H. Abelson, Synthetic Membranes, Science, 244, 1421 (1989).
  4. C. Liu and C. R. Martin, Composite Membranes from Petrochemical Synthesis of Ultra Thin Polymer Membranes, Nature, 352, 50-52 (1991).
  5. M. R. Anderson, B. R. Mattes, H. Reiss, and R. B. Kaner, Conjugated Polymer Films for Gas Separation, Science, 252, 1412-1415 (1991).
  6. S. H. Ahn, J. A. Seo, J. H. Kim, Y. Ko, and S. U. Hong, Synthesis and Gas Permeation Properties of Amphiphilic Graft Copolymer Membranes, J. Membr. Sci., 345, 128-133 (2009).
  7. S. U. Hong, J. H. Jin, J. Won, and Y. S. Kang, Polymer-Salt Complexes Containing Silver Ions and Their Application to Facilitated Olefin Transport Membrane, Adv. Mater., 12, 968-970 (2000).<968::AID-ADMA968>3.0.CO;2-W
  8. Y. Seo, S. U. Hong, and B. S. Lee, Overcoming the Upper Bound in Polymeric Gas-Separation Membranes, Angew. Chem. Int. Ed., 42, 1145-1149 (2003).
  9. H. B. Park, C. H. Jung, Y. M. Lee, A. J. Hill, S. J. Pas, S. T. Mudie, E. V. Wagner, B. D. Freeman, and D. J. Cookson, Polymers with Cavities Tuned for Fast Selective Transport of Small Molecules and Ions, Science, 318, 254-258 (2007).
  10. J. I. Choi, C. H. Jung, S. H. Han, H. B. Park, and Y. M. Lee, Thermally rearranged (TR) poly(benzoxazole-co-pyrrolone) membranes tuned for high gas permeability and selectivity, J. Membr. Sci., 349, 358-368 (2010).
  11. M. Carta, R. M. Evans, M. Croad, Y. Rogan, J. C. Jansen, P. Bernardo, F. Bazzarelli, and N. B. McKeown, An Efficient Polymer Molecular Sieve for Membrane Gas Separations, Science, 339, 303-307 (2013).
  12. H. W. Kim, H. W. Yoon, S. Yoon, B. M. Yoo, B. K. Ahn, Y. H. Cho, H. J. Shin, H. Yang, U. Paik, S. Kwon, J. Choi, and H. B. Park, Selective Gas Transport Through Few-Layered Graphene and Graphene Oxide Membranes, Science, 342, 91-95 (2013).
  13. W. S. Choi, S. U. Hong, B. Jung, S. W. Kang, Y. S. Kang, and J. H. Kim, Synthesis, Structure and Gas Permeation of Polymerized Ionic Liquid Graft Copolymer Membranes, J. Membr. Sci., 443, 54-61 (2013).
  14. B. D. Freeman, Basis of Permeability/Selectivity Tradeoff Relations in Polymeric Gas Separation Membranes, Macromolecules, 32, 375-380 (1999).
  15. R. Fortunato, C. A. Afonso, M. A.Reis, and J. G. Crespo, Supported liquid membranes using ionic liquids: study of stability and transport mechanisms, J. Membr. Sci., 242, 197-209 (2004).
  16. C. Cadena, J. L. Anthony, J. K. Shah, T. I. Morrow, J. F. Brennecke, and E. J. Maginn, Why Is $CO_2$ So Soluble in Imidazolium-Based Ionic Liquids?, J. Am. Chem. Soc., 126, 5300-5308 (2004).
  17. Y. Hou and R. E. Baltus, Experimental Measurement of the Solubility and Diffusivity of $CO_2$ in Room-Temperature Ionic Liquids Using a Transient Thin-Liquid-Film Method, Ind. Eng. Chem. Res., 46, 8166-8175 (2007).
  18. J. E. Bara, T. K. Carlisle, C. J. Gabriel, D. Camper, A. Finotello, D. L. Gin, and R. D. Noble, Guide to $CO_2$ Separation in Imidazolium-Based Room-Temperature Ionic Liquids, Ind. Eng. Chem. Res., 48, 2739-2751 (2009).
  19. J. Ilconich, C. Myers, H. Pennline, and D. Luebke, Experimental investigation of the permeability and selectivity of supported ionic liquid membranes for $CO_2$/He separation at temperatures up to $125^{\circ}C$, J. Membr. Sci., 298, 41-47 (2007).
  20. S. U. Hong, D. Park, Y. Ko, and I. Baek, Polymer-Ionic Liquid Gels for Enhanced Gas Transport, Chem. Commun., 7227-7229 (2009).