Carbon nanotubes doped SiO_2/SiO_2-PbO double layer high emissivity coating

摘要

Carbon nanotubes (CNTs) doped SiO_2/SiO_2-PbO double layer coating is prepared on Ni alloy plate by hybrid SiO_2 sol-gel method and SiO_2-PbO powders with certain heat treatment. The SiO_2-PbO top layer is observed to possess a kind of porous and skeleton-like structure. The emissivity enhancement mechanisms of the coating's structure and doping carbon nanotubes are investigated in this study. Spectral emissivity measurements from 1.28 to 25 μm at 570 and 820 K show that the carbon nanotubes doped SiO_2/SiO_2-Pb0 double layer coating possesses strong blackbody character and the coating's emissivity can reach as high as 0.94 at 820 K.