Pulsed electropolymerization of PEDOT enabling controlled branching

Abstract

Controlling the growth of conductive polymers via electrolysis enables defined surface modifications and can be used as a rapid prototyping process. In this study, the controlled dendritic growth of poly(3,4-ethylenedioxythiophene) in a two-electrode setup was investigated by pulsed voltage-driven electropolymerization of the precursor EDOT and a low concentration of tetrabutylammonium perchlorate dissolved in acetonitrile. Rapid growth of different polymeric shapes was reliably achieved by varying the reduction voltage and duty factor. The obtained structures were optically examined and quantified using fractal dimensions. Their shapes ranged from solid coatings over branched fractals to straight fibers without requiring any template. These rapid and controllable electropolymerization processes were further combined to increase conductor complexity. Poly(3,4-ethylenedioxythiophene) (PEDOT) was electropolymerized from 50 mm EDOT with 1 mm tetrabutylammonium perchlorate, and acetonitrile. Stable and controllable growth of fractal PEDOT structures was achieved by varying the parameters of the voltage-driven pulsed electropolymerization. A box-counting method was used to determine the fractal dimension fdim, allowing a distinct classification of the different structures and branching. The underlying migration-driven processes enable rapid and directed growth of complex conductive structures.