A new electrochromic copolymer which switched between neutral black and oxidized transmissive. Issue 83 (23rd August 2016) - Wang, Chunlei
Abstract : A new type of electrochromic donor–acceptor type copolymer was obtained by the electrodeposition method. TheP(1- co -2) film exhibited a deep black color in the neutral state and a transmissive light gray color in the oxidized state. Abstract : In this study, two monomers, 4, 7-bis(2, 3-dihydrothieno[3, 4- b ][1, 4]dio-xin-5-yl)-2-dodecyl-2 H -benzo[1, 2, 3]triazole (M1 ) and 2, 3-di(5-methylfuran-2-yl)-5, 8-bis(2-(3, 4-ethylenedioxythiophene))quinoxaline (M2 ), were used for the preparation of a neutral black polymer. A black polymerP(1- co -2) was successfully achieved by the electrochemical copolymerization of the two monomers with a feed ratio of 1 : 1, and then the obtained polymer was well characterized.P(1- co -1) has a wide range of absorption in the range of 400–800 nm, which makes the polymer exhibit a deep black color in the neutral state, and a transmissive light gray color could be obtained in the oxidized state. The polymer has a low band gap of 1.20 eV. Besides, a high coloration efficiency, a fast response time, as well as high transmittance changes (more than 78%) in the near-IR region were also found with this polymer, which suggested that the polymer might be a feasible candidate for the fabrication of electrochromic devices.