A facile nanoarchitectonics of electrochromic devices with poly(3, 4-ethylenedioxythiophene) and bioplastic composite

Recently, electrochromic devices (ECDs) have been exploited extensively for various applications, including energy-saving and display. However, it is still critical to develop lightweight, low-power, inexpensive, and eco-friendly ECDs. In this study, a novel ECD based on poly(3,4-ethylene dioxythiophene)(PEDOT)/2,2,6,6-tetramethylpiperidine-1-oxy-oxidized cellulose nanofiber (TEMPO-CNF)/epoxy composites was developed through a simple solution-casting polymerization (SCP). The PEDOT layer coated on TEMPO-CNF/epoxy substrates (PEDOT/TEMPO-CNF/epoxy) functions as a conductive electrode that is simultaneously capable of undergoing reversible color change. The optimized PEDOT layer showed a high electrical conductivity of 1276.5 S/cm and a large transmittance contrast (ΔT) = 32.3 %. Novel bioplastic-based ECD with PEDOT/TEMPO-CNF/epoxy composites was constructed in this study by leveraging the advantages of the simple SCP process, high electrical conductivity, and large color contrast of the PEDOT layers. The fabricated ECD exhibited a reversible color transition from light blue (semi-transparent state) and dark blue (colored state) depending on the redox potential and showed a high coloration efficiency (CE) value of 223.3 cm2/C. This suggests that our approach could enhance our ability to create bioplastic-based ECDs with various conductive and electrochromic materials.