Role of polymerization temperature on the performance of polypyrrole/dodecylbenzenesulphonate linear actuators

Abstract

Polypyrrole doped with dodecylbenzenesulphonate (PPy/DBS) free-standing films were electropolymerized in sodium perchlorate propylene carbonate solution at different temperatures, observing increasing conductivity with decreasing synthesis temperature. Our goal in this study was to evaluate how the linear actuation of PPy depends on the polymerization temperature. The anion driven actuation of materials synthesized at lower temperatures changed to mainly cation active for PPy/DBS films polymerized at 20 °C; the latter films also showed the highest diffusion coefficients. Scanning electron microscopy did show that the surface roughness of the films increased with increasing synthesis temperature, as expected. Isometric and isotonic electro-chemo mechanical deformation (ECMD) measurements were performed with combined electrochemical techniques (cyclic voltammetry and chronoamperometry), revealing wide differences in the actuation behavior.