Development of spacecraft black thermal control coatings using the synthesized mesoporous Co3O4 pigment

The thermo-optical properties of coated surface are important for spacecraft thermal control coatings which depend on the optical properties and structure of the coating material. These coatings control the temperature by their capability of outer energy absorption and its emission. The optical properties of pigment can be improved if the pigment contains a high fraction of voids in its structure. In this paper, mesoporous Co3O4 powders were successfully synthesized through hard template method using SBA-15. The resulting black pigment was characterized using BET, XRD and FE-SEM. The reflective property of Co3O4 was investigated by diffuse reflectance ultraviolet-visible near-infrared spectrophotometer. Reflectance measurement revealed that these mesoprous materials had high absorption property αs0.95. The resulting mesoporous Co3O4 was mixed with potassium silicate as transparent binder to make coating on Al substrate that shows high solar absorptance αs0.94 and high thermal emittance εt0.96. This study indicated that Co3O4 coating may be a promising kind of black thermal control coatings.