Improved cathodic expansions of polypyrrole films by poly(2-methoxyaniline-5-sulfonate) incorporation

We describe the effect of conducting guest polymer, poly(2-methoxyaniline-5-sulfonate, PMAS), incorporation on the electrochemomechanical deforming (ECMD) characteristics of polypyrrole (PPy) film. The films electrodeposited in the aqueous solutions having dodecylbenzene sulfonate (DBS) as the main supporting electrolyte mixed with various amounts of PMAS as the polymer additive, exhibited the drastic change of ECMD behaviors as a function of PMAS content. A complicated ECMD behavior was observed for the PPy film having 5% PMAS dopant in 0.5 M KCl/aqueous solution, which turned to be a simple cathodic expansion (4.5% in strain) in 0.5 M tetra-bulyammonium tetra-fluoroborate/acetonitrile(AcCN) solution. The large cathodic expansion of 6.2% was observed in tetra-bulyammonium chloride/AcCN solution. Responses of ECMD behaviors of the films in Square-Wave Voltammetry (SWV) elucidate that the anion exchange is simultaneously occurred with cation exchange even in the cathodic expansive films. For the cathodic expansion of PPy film, the PMAS incorporation is effective to improve the deformation magnitude. The cathodic expansion should be improved in the judicious selection of electrolyte having bulky cation with small anion as well as preferable solvent.