Development of Zn2SiO4 and hexagonal BN inorganic thermal-control coatings with novel thermophysical property

Implementation of lightweight and long-lasting thermal-control coatings (TCCs) is vital for regulating the surface temperature and energy consumption of spacecraft. Herein, Zn 2 SiO 4 and hexagonal boron nitride (hBN) based inorganic TCCs are developed with potassium silicate binder. The α s /ε H (solar absorptance/ hemispherical emittance) ratio of the Zn 2 SiO 4 , ZnO and hBN coatings are 0.096, 0.190 and 0.107, respectively. Compared to the classical ZnO based Z-93 coating, both Zn 2 SiO 4 /K 2 SiO 3 and hBN/K 2 SiO 3 coatings show superior initial thermophysical properties. After vacuum-proton irradiation, the α s of Zn 2 SiO 4 , Z-93 and hBN coatings increased from 0.091, 0.167 and 0.098 to 0.193, 0.253 and 0.241, respectively. Apparently, the as-developed Zn 2 SiO 4 coating exhibits exceptional heat-dissipation and radiation-resistance features in relation to the hBN and Z-93 TCCs.