Abstract
The electrical properties (capacitance, resistance, and conductivity) of ion gel films were examined as a function of film geometry and temperature by using electrical impedance spectroscopy. Ion gel films, which consist of a triblock copolymer, poly (styrene-b-methyl methacrylate-b-styrene) [SMS], and an ionic liquid, 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide, [EMI][TFSI], were deposited by spin coating from ethyl acetate solution. The thickness (2.2-13.4 μm) and the area (0.01-0.06 cm(2)) of the film sandwiched between two gold electrodes were varied systematically to investigate the relation between the electrical properties and the geometry of the film. The resistance (R) was directly proportional to the thickness and the reciprocal area, as expected, whereas the specific capacitance (C') was insensitive to the film geometry. Importantly, the gel polarization time constants (RC, where C = C' × area) were as small as 2.8 μs for 2.2 μm thick ion gel films. Conductivity and capacitance of the film both increase with increasing temperature, with conductivity following the Vogel-Fulcher-Tamman equation, indicating entropically activated behavior, and capacitance at 10 Hz showing Arrhenius-type activation.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.