Photonic Crystal Films Combining Hydrophobicity and Multiband Stealth Performance

Photonic crystal material with low infrared emissivity has potential applications in the field of stealth. In order to improve its performance in the salt-spray environment, the fluorocarbon-photonic crystal film is designed through the magnetron sputtering technology. According to the simulation and experiment results, it indicates that when the thickness of the functional layer is 150 nm, it has little effect on the infrared emissivity of the photonic crystal, and the infrared emissivity of the composites increases only by 0.022 and 0.007. In the 3–5 μm and 8–14 μm bands, the infrared emissivity of the composites increases by 0.228 and 0.172, respectively, when the thickness of the hydrophobically modified film is increased to 1,000 nm. Furthermore, the use of the fluorocarbon film enhances the hydrophobicity of the photonic crystal film by approximately 1.5 times. The composite film exhibits better salt spray resistance after 240 hours of erosion, with minimal changes in IR emissivity and static contact angle, compared to the photonic crystal without the fluorocarbon film. The photonic crystal composite film can be used in high humidity, rainy, and salt spray environments to prevent degradation of stealth film performance.