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Physical and Thermodynamic Properties of Imidazolium Ionic Liquids

이미다졸계 이온성 액체의 물성

  • Oh, Sooyeoun (Department of Chemical and Biological Engineering, Korea National University of Transportation) ;
  • Kang, Jeong Won (Department of Computer Engineering, Korea National University of Transportation) ;
  • Park, Byung Heung (Department of Chemical and Biological Engineering, Korea National University of Transportation) ;
  • Kim, Ki-Sub (Department of Chemical and Biological Engineering, Korea National University of Transportation)
  • 오수연 (한국교통대학교 화공생물공학과) ;
  • 강정원 (한국교통대학교 컴퓨터공학과) ;
  • 박병흥 (한국교통대학교 화공생물공학과) ;
  • 김기섭 (한국교통대학교 화공생물공학과)
  • Received : 2012.03.12
  • Accepted : 2012.04.13
  • Published : 2012.08.01

Abstract

Ionic liquids (ILs) existing as liquid state at room temperature are composed of a immense heterocyclic cation and inorganic anion which is smaller than cation's size. Thus, the species of cation and anion as well as the length of alkyl group on the cation have influence on their physical properties. Their outstanding properties such as non-volatility, thermal stability and wide range of electrochemical stability make these materials excellent candidates for green solvent which can substitute the conventional organic solvents. In this study, ILs based on imidazolium cation have been synthesized such as 1-butyl-3-methylimidazolium bromide ([BMIM][Br]), 1-butyl-3-methylimidazolium chloride ([BMIM] [Cl]), 1-butyl-3-methylimidazolium iodide ([BMIM][I]), and 1-butyl-3-methylimidazolium tetrafluoroborate ([BMIM][$BF_4$]). The density, viscosity, refractive index, heat capacity and ionic conductivity of [BMIM][Br], [BMIM][I], and [BMIM] [$BF_4$] were measured over range of temperature of 293.2 to 323.2 K. The density and refractive index values of [BMIM][I] were the highest among three ILs and the viscosity values of [BMIM][Br] were the highest among three ILs. The heat capacities [BMIM][$BF_4$] were higher than those of [BMIM][Br]. The ionic conductivities of [BMIM][$BF_4$] were higher than those of [BMIM][I].

이온성 액체는 일반적으로 거대 헤테로 고리 양이온과 무기 음이온으로 이루어진 염으로, 상온에서 액체로 존재한다. 따라서 이온성 액체의 물성은 양이온과 음이온의 종류, 알킬기의 수에 영향을 받으므로 그 조합에 의해 이온성 액체 각각의 물성이 달라진다. 또한 비휘발성, 열적 안정성, 넓은 전기 화학적 범위를 가지므로 기존의 유기용매를 대체할 주목할 만한 청정 용매(Green solvent)이다. 본 연구에서는 1-Butyl-3-methylimidazolium bromide ([BMIM][Br]), 1-butyl-3-methylimidazolium Chloride ([BMIM][Cl]), 1-butyl-3-methylimidazolium iodide ([BMIM][I]) 그리고 1-butyl-3-methylimidazolium tetrafluoroborate ([BMIM][$BF_4$])을 합성하였으며, 그 중 [BMIM][Br], [BMIM][I], [BMIM][$BF_4$]의 밀도, 점도, 굴절률, 열용량과 이온전도도를 293.2~323.2 K의 온도범위에서 측정하였다. 밀도와 굴절률은 [BMIM][I]가 세 이온성 액체 중 가장 높았으며, 점성은 [BMIM][Br]가 가장 높았다. 열용량은 [BMIM][Br]보다 [BMIM][$BF_4$]가 높았으며, 이온 전도도는 [BMIM][I]보다 [BMIM][$BF_4$]가 더 높았다.

Keywords

Acknowledgement

Supported by : 한국연구재단

References

  1. Ngo, H. L., Lecompte, K., Hargens, L. and McEwen, A. B., "Thermal Properties of Imidazolium Ionic Liquids," Thermochim. Acta., 97, 357-361(2000).
  2. Huddleston, J. G., Willauer, H. D., Swatloski, R. P., Visser, A. E. and Rogers, R. D., "Room Temperature Ionic Liquids as Novel Media for 'clean' Liquid - Liquid Extraction," Chem. Comm., 1765-1766 (1998).
  3. Ryu, S.-W. and Song, E.-H., "Characterization of Ionic Liquid Contained Polymer Gel Electrolyte," Polymer (Korea), 32(1), 85-89.
  4. Zhao, D., Fei, Z., Geldbach, T. J., Scopelliti, R. and Dyson, P. J., "Nitrile-functionalized Pyridinium Ionic Liquids: Synthesis, Characterization, and Their Application in Carbon-carbon Coupling Reactions," J Am Chem Soc., 15876-15882(2004).
  5. Scurto, A. M., Aki, S. N. V. K. and Brennecke, J. F., "Carbon Dioxide Induced Separation of Ionic Liquids and Water," Chem Comm., 572-573(2003).
  6. Marsh, K. N., Deev, A., Wu, A. C.-T., Tran, E. and Klamt, A., "Room Temperature Ionic Liquids as Replacements for Conventional Solvents - A Review," Korean J. Chem. Eng., 19(3), 357-363(2002). https://doi.org/10.1007/BF02697140
  7. Gale, R. J. and Osteryoung, R. A., "Potentiometric Investigation of Dialuminium Heptachloride Formation in Aluminum Chloride-1-butylpyridinium Chloride Mixtures," Inorg. Chem. 18(6), 1603-1605(1979). https://doi.org/10.1021/ic50196a044
  8. Hagiware, R. and Ito, Y., "Room Temperature Ionic Liquids of Alkylimidazolium Cations and Fluoroanions - A Review," J. Fluor. Chem., 105, 221-227(2000). https://doi.org/10.1016/S0022-1139(99)00267-5
  9. Bonhte, P., Dias, A.-P., Papafeorgiou, N., Kalyanasundaram, K. and Grtzel, M., "Hydrophbic, Highly Conductive Ambient-Temperature Molten Salts," Inorg. Chem., 35, 1168-1178(1996). https://doi.org/10.1021/ic951325x
  10. Pereiro, A. B., Verdia, P., Tojo, E. and Rodriguez, A., "Physical Properties of 1-Butyl-3-methylimidazolium Methyl Sulfate as a Function of Temperature," J. Chem. Eng. Data., 52, 377-380(2007). https://doi.org/10.1021/je060313v
  11. Gordon, C. M., Holbrey, J. D., Kennedy, A. R. and Seddon, K. R., "Ionic Liquid Crystals: Hexafluorophosphate Salts," J. Mater. Chem., 8, 2627-2636(1998). https://doi.org/10.1039/a806169f

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