A comprehensive study of electrochromic device with variable infrared emissivity based on polyaniline conducting polymer

In this study, dodecylbenzene sulfonate acid (DBSA) doped-polyaniline (PANI) films were synthesized in situ on Au/porous flexible substrate by electrochemical deposition. The emissivity change (△ε) data of PANI films show a reversal from positive to negative as the polymerization charge increases. This trend can be explained by using the Drude free electron theory and the Hagen-Rubens approximation at low frequency due to the pseudo-metallic behavior of conducting polymers. The DBSA doped-PANI film was used as an active layer to fabricate an infrared (IR) electrochromic device. The △ε of this IR electrochromic device was measured to be 0.183, 0.388, and 0.315 in the wavelength ranges of 3–5 µm, 8–12 µm, and 2.5–25 µm, respectively. IR thermal images visually obtained from an IR thermal imager suggest that the IR electrochromic device possesses regulating capacity of thermal radiation within the operating waveband of the instrument (7.5–14 µm). The IR electrochromic device developed in this work can be potentially used in IR camouflage for military and thermal control for satellite.