Resumen
In this paper, we wish to report the preparation of ultra-black films via spraying coatings composed of waterborne binders and low-cost carbon aerogels on pre-treated tinplate. The CAs were prepared by annealing resorcinol-formaldehyde resin (RF resin) and the following CO2 activation, of which the reflectance was less than 0.4% in a wide wavelength range. The reflectance of different coatings, which using CAs as functional pigments, ranged from 1.8% to 4.3% in the visible light region (400-760 nm), while it ranged from 1.9% to 4.2% in the near-infrared region (760?1100 nm). Further studies revealed the relationship between the pigment-to-binder ratio and reflectance and found the best ratio to be 0.96, and the minimum reflection was less than 1.8%. Outstanding adhesion to the tinplate substrate was also achieved using a two-component polyurethane binder after the thermal cycling test carried out from -100 °C to 100 °C. The fabrication process of ultra-black coatings is particularly convenient to remove the constraints of high costs and complex processes, making it instructive guidance for industrial production.