Design and optical performance investigation of all-sprayable ultrablack coating

ABSTRACT

Although ultrablack surfaces are urgently needed in wide applications owing to their extremely low reflectance over a broadband wavelength, obtaining simultaneously the ultrablackness and mechanical robustness by simple process technique is still a great challenge. Herein, by decoupling different light extinction effects to different layers of coating, we design an ultrablack coating that is all-sprayable in whole process. This coating presents low reflectance over visible–mid-infrared (VIS–MIR) wavelength (av. R ≈ 1% in VIS), low multi-angle scattering (bidirectional reflection distribution function (BRDF) = 10^-2–10^-3sr^-1), together with good substrate adhesion grade and self-cleaning ability, which are superior to most reported sprayable ultrablack surfaces. The light extinction effects of each layer are discussed. This method is also applicable in other material systems.

KEYWORDS

ultrablack, spray-coating, carbon nanomaterials, multiple scattering, intermediate layer