Enhancing thermal control performance of hierarchical porous ZrO₂@AZO-ACR antistatic coating optimized by non-solvent polarity difference

Thermal control coatings (TCCs) play a crucial role in managing the temperature of spacecraft. However, most of the reported organic TCCs have a relatively high ratio of solar absorptivity to emissivity (α_s/ε) and their space stability still needs to be improved, which cannot meet the thermal control requirements of future miniaturized and integrated spacecraft. Therefore, it is urgent to develop high-performance organic antistatic TCCs. Herein, hierarchically porous ZrO₂@AZO-acrylate (ZrO₂@AZO-ACR) antistatic TCCs were synthesized by combining the atomic layer deposition (ALD) technology and the non-solvent polarity difference induced phase separation method. The developed coating by using water and ethanol mixed solvents exhibits excellent thermal control performance (α_s∼0.118, α_s/ε∼0.132) and a low volume resistivity (2.5 × 10⁶ Ω·m). Both experimental results and FDTD simulations indicate that the presence of a hierarchically porous structure with a wider size distribution and a high content of large-sized micropores enhances the scattering efficiency within the solar spectrum, thereby increasing the solar reflectivity of the ZrO₂@AZO-ACR coating. Furthermore, the obtained ZrO₂@AZO-ACR antistatic coating demonstrates strong adhesion to multi-substrate materials and good space stability under electron irradiation, UV irradiation and extreme temperatures. This study provides a novel strategy for preparing high-performance TCCs with good space stability.