Synthesis of transparent and durable antimony tin oxide coatings based on spectrum-selective transmittance for thermal insulation by regulating dispersion

Primary energy consumption in buildings is mainly attributed to heat exchange through windows. However, developing transparent and durable thermal insulation coatings for practical applications remains challenging. Therefore, based on the spectrally selective transmittance mechanism, a transparent antimony tin oxide (ATO) inorganic coating for thermal insulation is presented using a simple blending method with low melting point glass powder. The visible light (VIS) transmission and near-infrared (NIR) shielding of the coating reaches 73.33 % and 61.87 %, respectively, under the ball-milling at 200 rpm for 60 min with ATO content of 0.3 g and calcination temperature of 700 °C. The optimized ball-milling pre-blending benefitted the transformation into smaller particle sizes and coating dispersion—crucial for affecting the spectral selective transmittance of the coating. The mechanism of introducing the low-melting-point glass powder, whose cross-linking with ATO by bridging oxygen conduces the disintegration and polymerization of the glass mesh to a denser network structure, was explored. The coating exhibited good durability and stability against abrasion for at least 150 cycles, acid and alkali resistance within 28 d, sunlight exposure, and heat treatment at 105 °C with nearly no change in the light-selective transmittance. The water resistance of the coating was also excellent, indicating the expanded potential of inorganic coatings for outdoor applications. Additionally, the temperature difference between the coated glass in the device and the uncoated glass reached up to 5.2 °C. This study provides a reference for preparing stable and transparent thermal insulation coatings.