Antifreezing and self-healing organohydrogels regulated by ethylene glycol towards customizable electrochromic displays

Abstract

Though numerous patterned electrochromic (EC) displays have been developed, a low-cost, eco-friendly and convenient strategy for fabricating customizable EC displays with great low and high temperature adaptability is still desired urgently. Herein, an antifreezing and self-healing EC oganohydrogel with reversible Schiff base linkages was prepared facilely through mixing a chitosan solution based on a water/ethylene glycol (EG) binary solvent and a dibenzaldehyde-modified poly(ethylene oxide) aqueous solution, and its mechanical and electrochromic properties can be regulated by EG content. The optimized gel exhibits a high ionic conductivity of 0.2 mS cm−1 at -60 ℃ and the EC gel-based device shows great cyclic stability with 99%, 98% and 95% optical modulation retention after 1000 cycles at different temperature of -30 ℃, 20 ℃ and 45 ℃, respectively. By extruding the EC gels from syringes onto transparent electrodes to form the specific patterns or characters, a series of customized EC displays for convey information were obtained. Such EC displays are expected to exhibit unique advantages over a wide operating temperature range and become a paradigm for future EC displays manufacturing.