Abstract:
The emergence of electronically conducting polymers having fascinating properties has opened
up a novel class of polymers suitable for modern applications, including smart soft actuators or
‘artificial muscles”. The change in volume of these polymers when the redox state is altered in
aqueous electrolytes is exploited in these actuators. The actuation property of these polymers highly
depends on cycling electrolytes, types, and concentrations. The present study aims to explore the
possibilities to use Polypyrrole, doped with the immobile anion dodecyl benzene sulfonate
(PPy/DBS) films cycled in LiCl and BaCl2 electrolytes. In this study, PPy (DBS) films of thickness
400 nm were electropolymerized on 6 MHz AT-cut quartz crystal electrodes from a synthesized
solution containing 0.05 M pyrrole monomer in 0.05 M NaDBS solution and characterized by
simultaneous cyclic voltammetry and Electrochemical Quartz Crystal Microbalance (EQCM)
measurements. The films were cycled in 0.1 M BaCl2 0.1 M LiCl, 2 M LiCl, and 1 M BaCl2
electrolytes. The actuation mechanism of the film in LiCl electrolytes (up to 2M concentrations)
is exclusively based on cations motions while that in BaCl 2 (up to 1M concentrations) is
contributed with both cations and anions in electrolytes. It implies that the redox ionic motion
resulting from the actuation of PPy (DBS) films is not exclusively based on metallic ion
presence in the electrolyte but depends on the type of metallic ions present in the cycling
electrolytes used. When compared with high and low concentrations in LiCl and BaCl2, a larger
frequency change was obtained in low concentrations rather than in higher concentrations,
indicating that the actuation in thin concentrations is larger than higher.
