Low-emissivity materials are regarded as promising candidates for thermal insulation. However, aesthetic concerns often hinder their practical application, primarily due to metallic gray coloration. While some colorful low-emissivity paints have been developed to address this issue, the labor application costs and complex preparation processes remain significant drawbacks. Here, a new category of self-stratifying colorful low-emissivity paints (SSCLPs) is presented, engineered to spontaneously form a distinct bilayer structure with a single application, thus eliminating the need for a second coat. Through careful formulation, the resulting bilayer coating features a highly reflective bottom layer and an infrared (IR)-transparent colored top layer, demonstrating low mid-infrared emissivity (as low as 0.107), high near-infrared reflectance (up to 0.814), and selectively visible reflectance for desired colors. Simulations confirm that effective stratification is essential for achieving the desired optical properties. Thermal insulation experiments demonstrate that SSCLPs can efficiently resist radiative heat transfer. Furthermore, building energy simulations indicate that SSCLP application to a two-story office building can yield annual heating, ventilation and air conditioning (HVAC) savings of up to 13.38 MJ m − 2 , with an associated CO 2 emission reduction of 1.1 kg m − 2 . This study contributes to advancing thermal insulation materials that promote energy savings and sustainability objectives.
Ceramic aerogels play an essential role in the field of high-temperature insulation. However, the significant radiation heat transfer limits the practical applicability. Herein, we have chosen mullite nanosheets prepared successfully by chemical blowing as structural assembly units, modified on the surface of mullite nanosheets with TiO2 nanorods to reduce infrared radiation heat transfer, and prepared mullite nanosheet/TiO2 nanorod/silica composite aerogels by adding silica sols as high-temperature binder cast molding in the system. The preferred composite aerogels have good temperature resistance, and the linear shrinkage was measured to be only 2% after calcination at 1500 °C for 30 min and had a low thermal conductivity (0.0356 W·m–1·K–1 at room temperature and 0.118 W·m–1·K–1 at 1000 °C). This assembly concept pervades a strategy for developing porous aerogel materials for insulation and protection in extreme environments.
Effective thermal management is essential to maintain spacecraft within normal operating temperature range. Inorganic white paint, as thermal control coating, owing to excellent spatial environmental stability and simple processing, hold significant prospects on spacecraft. However, the existing one suffers from unsatisfactory solar spectral reflectivity, which severely limits its use. To address this, we develop a hierarchical porous inorganic white paint by leveraging pigment particles transport during the spraying process. This design ensures pore sizes of the paint are predominantly distributed in the visible and near-infrared regions, which correspond to higher energy distribution in the solar spectrum, enhancing solar reflectivity. Ultimately, the white paint offers a higher solar reflectivity of 89.5 % across the 0.2–2.5 μm, an equilibrium temperature of 227.5 K under AM 0 illumination, and a net radiative power of 86.9 W/m 2 at 300 K, which lowers the temperature by approximately 4 °C compared to commercial inorganic one. Furthermore, the white paint retains superior performance after ultraviolet irradiation of 1000 ESH, which substantiates its long-term stability under extreme space environments. Apparently, the hierarchical porous inorganic white paint in this study exhibits significant potential for thermal management in space, holding the promise for assuming a significant role in future deep space exploration endeavors.
危险品化学品经营许可证（带存储）