A Free‐standing electrochromic material of poly(5,7‐bis(2‐(3,4‐ethylenedioxy)thienyl)‐indole) and its application in electrochromic device

Abstract

Free‐standing poly(5,7‐bis(2‐(3,4‐ethylenedioxy)thienyl)‐indole) (PETI) was electrochemically obtained from 5,7‐bis(2‐(3,4‐ethylenedioxy)thienyl)‐indole (ETI) prepared by Stille coupling reaction of 5,7‐dibromoindole and 3,4‐ethylenedioxythiophene. For comparison, poly(5,7‐bis(2‐thiophene)‐indole) was also electrosynthesized from 5,7‐bis(2‐thiophene)‐indole (BTI) which was prepared from the 5,7‐dibromoindole and thiophene. Characterizations of ETI and BTI were performed by cyclic voltammetry, scanning electron microscopy, 1H NMR, and 13C NMR spectroscopy. Spectroelectrochemical studies showed PETI had better electrochromic properties and showed two different colors (brown and blue‐violet) under various potentials with better maximum contrast (ΔT%) and coloration efficiency (CE). An electrochromic device (ECD) based on PETI and poly(3,4‐ethylenedioxythiophene) (PEDOT) was also constructed and characterized. This ECD had fast response time, high CE, better optical memory, and long‐term stability. These results indicated that PETI had potential applications for ECD. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017, 55, 2356–2364

Oligoaniline-containing electrochromic polymers with tunable properties

“…With the addition of current consumption, the coloration efficiency of these polymers are calculated to be 47 cm 2 /C (ECPA), 66 cm 2 /C (ECPA-TA), 53 cm 2 /C (ECPA-POSS), and 57 cm 2 /C (ECPA-F), respectively. Although the resulting coloration efficiency values are quite low compared to recent results from conjugated electrochromic polymers [4,24,25], the prepared polymer are still qualified as electrochromic material in the applications of light-adapting mirrors and smart windows. In addition, the switching speeds of the polymers are also determined from Figure 5b.…”

“…Conjugated polymers are promising electrochromic materials, due to their tunable properties through molecular design and synthesis [1][2][3][4][5]. The vast toolbox of organic chemistry enables facile chemical engineering of molecular structure to improve electrochromic performance.…”

High‐quality freestanding flexible poly(5‐(2,3‐dihydrothieno[3,4‐b][1,4]dioxin‐5‐yl)‐1H‐indole) film: Electrosyntheses, characterization, and optical properties

“…However, PEDTI film had a smooth and compact surface (Figure C) and was peeled into flawless freestanding film (Figure D). The micromorphology of PEDTI film was different from that of PETI consisting of small particles . The flawless freestanding property of PEDTI film stemmed from crosslinking polymer film formation.…”

“…The copolymer obtained at the feed ratio of monomers of 50:50 showed an effective corrosion protection. In addition, EDOT‐bis‐substituted indole precursor, 5,7‐bis(2‐[3,4‐ethylenedioxy]thienyl)indole (ETI), and its polymer (PETI) have been synthesized and electrochemically prepared by Nie's group . The electrochromic device based on PETI and PEDOT exhibited fast response time, high coloration efficiency, and long‐term stability.…”

Eco-friendly redox mediator gelatin-electrolyte for simplified TiO2-viologen based electrochromic devices

“…However, as a general trend, the electrochromic performance of ECDs based on 2 oxides suffer from a non-negligible operating voltage and a switching time considered as too slow for various applications. Nowadays, the development of ECDs technology is largely focused on π-conjugated polymers [21][22][23][24][25] such as polyaniline and poly (3,4-ethylendioxythiophene) PEDOT [26][27][28][29][30][31] or chromophore molecules such us bipyridilium derivatives and viologen [32][33][34]. Hence, high coloration efficiency and fast optical switching time at low operating potentials, including reasonable cost of preparation, are the reasons for which they are classified among the most promising electrochromic materials in the future.…”