The electrochromic properties of thin films prepared by electropolymerization of pyrrole and 2,2' bithiophene are described. The films change color reversibly when they are electrochemically cycled. The response times are less than 150 ms and the stability under repetitive cycling is good (105 cycles). The electrochromic parameters are compared to those of other electrochromic polymers.
M. Gazard, M. Gazard,
"Electrochemically Polymerized Heterocycles As Electrochromic Materials", Proc. SPIE 0400, New Optical Materials, (18 September 1983); doi: 10.1117/12.935495; https://doi.org/10.1117/12.935495