Dual polymer electrochromic adaptive camouflage devices for multiple environments based on quaterthiophene polymer and optional ion storage layers

The potential for electrochromic materials/devices to be utilized as adaptive camouflage for multiple environments remains to be investigated. In this work, the solution processible electrochromic polymers 4TBC and 4TCSIB were constructed using quaterthiophene as the basic electrochromic unit and tetraphenylsilane/meta benzene units as the conjugation break spacers. Taking advantage of the well-defined redox behavior of quaterthiophene, both polymers can switch from yellow to green series. In particular, 4TBC has better electrochromic performance, including high optical contrast and available cycle stability. Furthermore, the color-complementary polymer pEKE and pEBE were selected as the optional ion storage layer to design and construct dual polymer electrochromic adaptive camouflage devices. The electrochromic device-1 (ECD-1 (4TBC-pEKE)) and electrochromic device-2 (ECD-2 (4TBC-pEBE)) can switch from diverse yellow to different green at an operating voltage of -0.3 V similar to 1.2 V. Most importantly, we introduce the ECD-12, which integrates ECD-1 and ECD-2, can realize multiple modes (up to eighteen modes) conversion, and is expected to be applied to savanna, mountain and multiple environments. This work proposes an existing generic strategy of optional ion storage layers for constructing dual polymer electrochromic devices toward multiple environments adaptive camouflage.