Electrosynthesises and characterizations of copolymers based on pyrrole and 3,4-ethylenedioxythiophene in aqueous micellar solution

Copolymers based on pyrrole and 3,4-ethylenedioxythiophene (EDOT) are electrodeposited on indium tin oxide (ITO) electrode with various feed ratio of pyrrole/EDOT in aqueous micellar solution. The structures of the resultant copolymers are characterized via cycle voltammograms, Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and spectroelectrochemical analysis. Different electrochromic properties can be achieved by the copolymers prepared with various pyrrole/EDOT ratios. The π-π* transition absorption peak (λmax) of the deposited copolymer with the pyrrole/EDOT ratio of 1/10 at the neutral state is located at 542 nm and the calculated energy gap (Eg) is 1.82 eV. Moreover, successive CVs indicate the copolymer film has a better electrochemical stability, retaining 80% of the original electroactivity after 1000 cycles, which mainly results from the incorporation of EDOT units into the Ppy.