Copolymers Based on 1,3-Bis(carbazol-9-yl)benzene and Three 3,4-Ethylenedioxythiophene Derivatives as Potential Anodically Coloring Copolymers in High-Contrast Electrochromic Devices

Chung-Wen Kuo; Teng-Lu Wu; Yuan-Chung Lin; Jeng-Kuei Chang; Ho-Rei Chen; Tzi-Yi Wu

doi:10.3390/polym8100368

Copolymers Based on 1,3-Bis(carbazol-9-yl)benzene and Three 3,4-Ethylenedioxythiophene Derivatives as Potential Anodically Coloring Copolymers in High-Contrast Electrochromic Devices

Polymers (Basel). 2016 Oct 19;8(10):368. doi: 10.3390/polym8100368.

Authors

Chung-Wen Kuo¹, Teng-Lu Wu², Yuan-Chung Lin³, Jeng-Kuei Chang⁴, Ho-Rei Chen⁵, Tzi-Yi Wu⁶

Affiliations

¹ Department of Chemical and Materials Engineering, National Kaohsiung University of Applied Sciences, Kaohsiung 80778, Taiwan. welly@cc.kuas.edu.tw.
² Department of Chemical and Materials Engineering, National Kaohsiung University of Applied Sciences, Kaohsiung 80778, Taiwan. danny116040@yahoo.com.tw.
³ Institute of Environmental Engineering, National Sun Yat-Sen University, Kaohsiung 804, Taiwan. yclin@faculty.nsysu.edu.tw.
⁴ Institute of Materials Science and Engineering, National Central University, Taoyuan 32001, Taiwan. jkchang@ncu.edu.tw.
⁵ Department of Chemical and Materials Engineering, National Kaohsiung University of Applied Sciences, Kaohsiung 80778, Taiwan. chz@cc.kuas.edu.tw.
⁶ Department of Chemical and Materials Engineering, National Yunlin University of Science and Technology, Yunlin 64002, Taiwan. wuty@yuntech.edu.tw.

Abstract

In this study, copolymers based on 1,3-bis(carbazol-9-yl)benzene (BCz) and three 3,4-ethylenedioxythiophene derivatives (3,4-ethylenedioxythiophene (EDOT), 3,4-(2,2-dimethylpropylenedioxy)thiophene (ProDOT-Me₂), and 3,4-ethylenedithiathiophene (EDTT)) were electrochemically synthesized and their electrochemical and electrochromic properties were characterized. The anodic copolymer P(BCz-co-ProDOT) with BCz/ProDOT-Me₂ = 1/1 feed molar ratio showed high optical contrast (ΔT%) and coloring efficiency (η), measured as 52.5% and 153.5 cm²∙C^-1 at 748 nm, respectively. Electrochromic devices (ECDs) based on P(BCz-co-EDOT), P(BCz-co-ProDOT), and P(BCz-co-EDTT) as anodic polymer layers, and poly(3,4-ethylenedioxythiophene)-poly(styrene sulfonic acid) (PEDOT-PSS) as cathodic polymer layer were fabricated. P(BCz-co-ProDOT)/triple-layer PEDOT-PSS ECD showed three different colors (light yellow, yellowish-blue, and dark blue) at different applied potentials. In addition, the highest optical contrast (ΔT%) of P(BCz-co-ProDOT)/triple-layer PEDOT-PSS ECD was found to be 41% at 642 nm and the coloration efficiency was calculated to be 416.5 cm²∙C^-1 at 642 nm. All ECDs showed satisfactory optical memories and electrochemical cyclic stability.

Keywords: coloration efficiency; conducting polymer; electrochemical polymerization; electrochromic device; optical contrast; poly(3,4-ethylenedioxythiophene)-poly(styrene sulfonic acid).