Strain–capacitance relationship in polymer actuators based on single-walled carbon nanotubes and ionic liquid gels

Abstract

We investigate the electromechanical properties of bucky-gel electrochemical actuators incorporating various amounts of single-walled carbon nanotubes and an ionic liquid electrolyte, 1-butyl-3-methylimidazolium tetrafluoroborate, that are able to convert electrochemical energy into mechanical energy. The interplay between mechanical and electrochemical effects is studied. The electromechanical responses are investigated by means of electrochemical impedance spectroscopy and bending displacement measurements. We develop a theoretical model that allows us to rationalize the electromechanical properties of the bucky-gel actuators. This model takes into account electrochemical stress due to the intercalation (de-intercalation) process, which generates the strain and bending of the actuators. We then analyze the relationship between the strain and the real part of the complex capacitance by introducing a strain-capacitance coefficient. This coefficient is related to the electrochemical stress and the amount of the ionic adsorption (desorption) at the double-layer. From a practical point of view, the determination of the strain-capacitance coefficient is helpful for characterizing and optimizing the performance of electrochemical actuators.

Fabrication and evaluation of multi-walled carbon nanotube polymer actuator using the electrospinning method

“…Therefore, it is thought that when the electrode films of the EAP actuator were made of nanofiber, the surface area of the electrode films of the EAP actuator increased and then the capacitance of the EAP actuator increased. 30) Although the nanofiber electrode film has a surface area about 100 times that of the cast electrode film in Fig. 5, the capacitance did not become 100 times larger.…”

Modulating Chirality-Selective Photoluminescence of Single-Walled Carbon Nanotubes by Ionic Liquids

“…Because SWCNTs appeared to be the least emissive in [C 4 -mim]­BF 4 , which is a widely used IL in conjunction with SWCNTs, ,,− we explored pathways for enhancing the emission of SWCNTs in this IL (Figure ). We found that by increasing the amount of water in [C 4 -mim]­BF 4 , the emission intensity of SWCNTs was completely restored.…”