THE ROLE OF THE COUNTERION DURING ELECTROPOLYMERIZATION OF POLYPYRROLE CAMPHOR SULFONATE FILMS

The electrochemical preparation of polypyrrole-based films doped with camphor sulfonate which exhibit an anisotropic molecular organization is reported. The role of the dopant in determining the final structure of the film is explored by polymerization from electrolytes containing mixed counter-ion species. Smaller counter-ion units are preferentially included in the growing polymer film at the expense of the bulkier camphor sulfonate units. The mechanism of electropolymerization is discussed, particularly with reference to the interactions between the growing chain and the electrolyte which are dependent upon the hydrophobic/hydrophilic nature of the dopant.