Bioinspired Dynamically Switchable PANI/PS-b-P2VP Thin Films for Multicolored Electrochromic Displays with Long-Term Durability

Electrochromism has attracted wide attention as futuristic adaptive camouflage technologies due to its reversible and sustainable optical modulation with low energy consumption. However, limited color control of the electrochromic materials has hampered its applications. Inspired by the remarkable dynamic camouflage capabilities of cephalopods, polyaniline (PANI) and polystyrene-block-poly (2-vinyl pyridine) (PS-b-P2VP) thin films are integrated to simulate chromatophores and iridophores in the skin of cephalopods, respectively. Herein, it is demonstrated that the adaptive lamellar PANI/PS-b-P2VP thin film exhibits a wide range of color control, switchable vivid coloration, and excellent durability. It serves as an ideal multicolored electrochromic platform due to the combined effect of electrochromism from PANI and structural coloration from PS-b-P2VP. Unambiguous evidence shows that optical properties of the PANI/PS-b-P2VP thin film are related to the thickness of each layer and nanostructure of PANI, pronounced color changes mainly depend on electronic states of PANI and transition of hydrated SO₄^2? ions between PANI and P2VP. The coloration mechanism is discussed using quantitative analysis via RGB color specification and optical transmittance and reflectance simulations. The new insights will advance the design of reflection-contributed superior multicolored electrochromic materials, and have great potential in the fields of displays and camouflage.