(40a) Functional Ion Gels: Block Polymer/Ionic Liquid Composites for Advanced Applications

Authors: 
Lodge, T. P., University of Minnesota



Ionic liquids possess many attributes that render them attractive candidates for diverse applications, including negligible volatility, high ionic conductivity, thermal and chemical stability, and tunable salvation. Block polymer self-assembly in ionic liquids can impart the desired nanostructure and mechanical integrity for a particular function, without compromising the performance of the ionic liquid. We illustrate these general principles in two specific cases using ABA triblocks with ionic-liquid compatible midblocks.  First, the extremely high specific capacitance combined with rapid ion motion makes ions gels superior gate dielectrics in organic thin film transistors. For example, the possibility of fully printed plastic circuitry with MHz switching will be demonstrated. Second the remarkable thermodynamic selectivity of certain ionic liquids for CO2 over N2 or CH4 offers a route to rapid membrane separations, if the ionic liquid can be suitably immobilized. An ABA system in which the midblock is itself a polymerized imidazolium salt serves this purpose, and performance above the famous “Robeson’s Upper Bound” has been achieved.