We investigate the influence of ionic liquids on the electromechanical performance of Ionic Polymer Conductor Network
Composite (IPCNC) bending actuators. Two imidazolium ionic liquids (ILs) with one cation, which is 1-ethyl-3-
methylimidazolium ([EMI+]), and two different anions, which are tetrafluoroborate ([BF4-]) and
trifluoromethanesulfonate ([Tf-]), are chosen for the study. By combining the time domain electric and
electromechanical responses, we developed a new model that describes the ion transports in IPCNC actuators. The time
constant of excess cation and anion migration in various composite electrodes are deduced: 6s and 25s in RuO2/Nafion;
7.9s and 36.3s in RuO2/Aquivion; 4.8s and 53s in Au/PAH, respectively. NMR is also applied to provide quantitative
measures of self-diffusion coefficients independently for IL anions and cations both in pure ILs and in ILs absorved into
ionomers. All the results indicate that the motion of cation, in the studied pure ionic liquids, polymer matrix and
conductor network composites, is faster than that of anion. Moreover, the CNC morphology is playing a crucial role in
determining the ion transport in the porous electrodes.
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