Strongly enhanced infrared emission of a black coating doped with multiwall carbon nanotubes

Advanced infrared emission coating materials with emissivities close to one unit are critical for producing high-performance standard black bodies. Herein, by utilizing a simple spray-coating method, we prepared a novel carbon-based coating with an organic binder by using VC 811-21 as the main phase and multiwall carbon nanotubes (MWCNTs) as the dopant to fulfil this demand. The addition of an optimal concentration of MWCNTs results in a smooth surface structure with a low roughness that is free of large granularities. The infrared emissivity in the wavelength region of 6.5-16 mu m presents a close dependence on the increasing concentration of MWCNTs. With 1 parts per thousand MWCNTs, the highest infrared emissivity in vacuum (0.985) is obtained with a spectral nonuniformity of 0.002, and this result is higher than the reported values of VC 811-21 and other well-known infrared coating materials. Such high infrared emissivity will greatly benefit the design of novel black bodies for next-generation infrared remote sensing.