Thermo-sensitivity of polymers and polymer gels in ionic liquids

I&EC 110

Takeshi Ueki, d04sa101@ynu.ac.jp and Masayoshi Watanabe, mwatanab@ynu.ac.jp. Department of Chemistry & Biotechnology, Yokohama National University, 79-5 Tokiwadai, Hodogaya-ku, Yokohama, 240-8501, Japan
Certain polymers greatly change their solubility in response to external stimuli such as temperature. Thermo-sensitive polymers and polymer gels have been recognized to have a potential to be applied to a switching or sensing device by using this transition. However, we have not been able to use such polymer gels under atmospheric pressure or high temperature for a long term, because conventional smart gel materials have a problem of the solvent evaporation. In this study, we tried to use phase-behavior of different polymers in 1-ethyl-3-methylimidazolium bis(trifluoromethane sulfone)imide (EMITFSI), which is a typical hydrophobic ionic liquid. It was found that certain polymer gels in EMITFSI change their volume in response to temperature. The polymer gels in the IL (“ion-gels”) are stable over a wide range of temperature, because the thermo-sensitive ion-gels include a non-volatile IL as the solvent.