Macromolecules, Vol.51, No.6, 2227-2231, 2018
Remarkable Ability To Modulate Light Transmittance and Block Heat in the Bleached State Combined in One Electrochromic Material: Highly Crystalline Polyaniline
It is revealed that chain ordering strongly affects optical and electrochromic properties of polyaniline. Polyaniline film with 70% crystalline phase combines the remarkable ability to modulate the light transmittance (coloration efficiency of 150 cm(2)/C with a contrast ratio approaching 10 at lambda = 633 nm) with an unprecedented "bright-cool" bleached state, where the polymer is highly transparent to light but has low transmittance for the most intense near-infrared irradiation. Compared to the recently developed dual-band electrochromic materials in which modulation of the near-infrared absorption is realized through plasmonic electrochromism of WO3-x nanoparticles, the highly crystalline polyaniline film demonstrates in the "bright-cool" regime a 10 times lower transmittance at 900 nm (1.6 vs 16%) with the same level (approximate to 160%) of transmittance in the visible region. The coloration efficiency found here is almost 3-fold higher than commonly communicated for polyaniline.