Effects of alkyl chain length on properties of N-alkyl-N-methylpyrrolidinium fluorohydrogenate ionic liquid crystals

• Xu, Fei

• Matsubara, Shohei

• Matsumoto, Kazuhiko

• Hagiwara, Rika

Abstract

A series of N-alkyl-N-methylpyrrolidinium fluorohydrogenate salts (CxMPyr(FH)2F, x = 10, 12, 14, 16, and 18) have been characterized by infrared spectroscopy, thermal analysis, polarized optical microscopy, X-ray diffraction, and anisotropic ionic conductivity measurements. Liquid crystalline mesophase with a smectic A interdigitated bilayer structure is observed for the salt with x ≥ 14, showing a fan-like or focal conic texture. Temperature range of the mesophase increases with increase in alkyl chain length (from 26.7 °C for C14MPyr(FH)2F to 90.7 °C for C18MPyr(FH)2F). The layer spacing in the smectic structure monotonously increases with increasing alkyl chain length and decreases with increasing temperature. The liquid crystalline mesophase of C14MPyr(FH)2F exhibits anisotropy in ionic conductivity and the ionic conductivity parallel to the smectic layer is roughly ten times larger than that perpendicular to the smectic layer.

Journal

• Journal of Fluorine Chemistry

  Journal of Fluorine Chemistry 135 344-349, 2012-03

  Elsevier B.V.

Keywords

• Ionic liquid
• Liquid crystal
• Pyrrolidinium
• Mesophase
• Conductivity

Details

• CRID: 1050001335729246592
• NII Article ID: 120003988208
• NII Book ID: AA11532299
• ISSN: 00221139
• HANDLE: 2433/154578
• Text Lang: en
• Article Type: journal article
• Data Source:
  • IRDB
  • CiNii Articles