Abstract

The preparation of copolymers bearing N-methylcarbazole and 2,7-linked 3,4-ethylenedioxythiophene units has been carried out using the N-methyl-2,7-di(2-(3,4-ethylenedioxythienyl))carbazole monomer, which has been chemically synthesized through the Stille coupling reaction of 2,7-dibromo-N-methylcarbazole and tributyl-stannylated 3,4-ethylenedioxythiophene. Then, the monomer was electropolymerized by chronoamperometry in acetonitrile with 0.1 M LiClO4 under a constant potential of 0.70 V and using steel AISI 316 electrodes. The electrochemical activity and stability, charge-discharge capacity, charge transfer resistance and surface properties (i.e. morphology, topography and wettability) of the resulting polymer have been characterized and compared with those reported for poly(3,4-ethylenedioxythiophene). Finally, the polymer has been obtained by potentiodynamic sweep, applying around 100 cyclic voltammetry steps to an acetonitrile solution of the N-methyl-2,7-di(2-(3,4-ethylenedioxythienyl))carbazole monomer with 0.1 M LiClO4. Results show that although this technique has been mostly used to electropolymerize diheteroaromatic-subtituted carbazoles, the resulting material presents serious disadvantages with respect to that produced by chronoamperometry under a constant potential.