POLY 340 |
| Room temperature ionic liquids such as imidazolium, pyridinium, and ammonium salts containing perfluorinated anions have advantages for applications as ion-transporting media in batteries as well as reaction media because of their non-volatility and high ionic conductivities. For further functionalization of ionic liquids, the introduction of ordered nanostructures that provide anisotropic conductivities in low dimensions is of great interest. Self-assembly of liquid crystals can be used to obtain such anisotropic functional materials. Recently, we have reported on one-dimensional ion-conductive polymer films that have macroscopically oriented ion-channels. Here we report on one-dimensional ion conductors based on columnar liquid-crystalline imidazolium salts containing tetrafluoroborate, hexafluorophosphate, and trifluoromethylsulfonate anions and their polymerizable derivatives. These columnar liquid-crystalline materials were macroscopically aligned in two directions on the substrates: parallel alignment by mechanical shearing and spontaneous vertical alignment through specific interactions between functionalized substrate and the imidazolium compounds. The ionic conductivities of the aligned materials were measured as a function of temperature. The ionic conductivities parallel to the columnar axis were higher than those perpendicular to the columnar axis. |
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Polymers and Liquid Crystals
8:30 AM-12:00 PM, Tuesday, August 21, 2007 Westin Boston Waterfront -- Otis, Oral
Division of Polymer Chemistry |