Pearl-Inspired Colored Carbon Fibers with Electromagnetic Interference and Optical Camouflage Properties

Carbon fibers (CFs) are widely used in cutting-edge and civilian fields due to their excellent comprehensive properties such as high strength and high modulus, superior corrosion and friction resistances, excellent thermal stability, light weight, and high electrical conductivity. However, their natural ultra-black appearance is difficult to meet the aesthetic needs of today's civilian sector and the need for optical stealth in the military field. In addition, conventional coloring methods are difficult to effectively adhere to CF surfaces due to high crystallinity and highly inert surface caused by their graphite-like structure. In this work, inspired by the nacre structural color of pearls, colored CFs with 1D photonic crystal structure are prepared by cyclically depositing amorphous (Al₂O₃ + TiO₂) layers on the surface of carbon CFs through atomic layer deposition (ALD). The obtained CFs exhibit brilliant colors and excellent environmental durability in extreme environments. Moreover, the colored CFs also exhibit high EMI shielding effectiveness (45 dB) and optical stealth properties, which can be used in emerging optical devices and electromagnetic and optical stealth equipment.