Electroactive Properties and Electrochemical Stability of Poly(3,4-ethylenedioxythiophene) and Poly(N-methylpyrrole) Multi-layered Films Generated by Anodic Oxidation

Multi-layered films of poly(3,4-ethylenedioxythiophene), and poly(N-methylpyrrole), have been prepared using a layer-by-layer electrodeposition technique. The electrochemical properties and the conductivity of the films formed by 3, 5 and 7 layers have been compared with their homopolymers and with the copolymers prepared from 3,4-ethylenedioxythiophene and N-methylpyrrole with different concentration ratios. The electroactivity and stability of the multi-layered systems were higher than those of PEDOT homopolymer and copolymers. Furthermore, the electrochemical properties improved when the number of layers increased. In addition, the electrical conductivity of the multi-layered films is higher than those of poly(N-methylpyrrole) and copolymers, and comparable to the PEDOT homopolymers. These results indicate that multi-layered systems show better performance than their homopolymers and/or copolymers derivatives for some applications like anticorrosive coatings or sensor materials.