Yang Huiyu, Chen Rong, Yu Guowen, Cheng Xiaohua, Zhao Liangang, Liu Hai, Deng Bo, Xu Zushun, Gong Chunli
School of Chemistry and Materials Science, Hubei Engineering University, Xiaogan 43200, China.
Key Laboratory for New Textile Materials and Applications of Hubei Province, Wuhan Textile University, Wuhan 430200, China.
Langmuir. 2025 Apr 8;41(13):9112-9121. doi: 10.1021/acs.langmuir.5c00717. Epub 2025 Mar 28.
Daytime radiant cooling achieves a sustainable cooling effect by reflecting sunlight and radiant heat. However, absorption of sunlight by emitters and parasitic heat gain can significantly reduce radiative cooling temperatures. To improve the light reflectivity and emissivity in the mid-infrared band, SNF@TiO aerogel with high stability and efficient radiative cooling effect was constructed using nanosilk and titanium dioxide. The hierarchical structure of the aerogel stores more air, which reduces the thermal conductivity (0.0333 W·m·K) and parasitic heat gain. TiO provides excellent UV resistance while increasing solar reflectance and atmospheric window emissivity. The average solar reflectance and average IR emissivity of SNF@TiO were 89.4 and 92.3%, respectively. Compared with the subambient (: 800 W·m, PE-covered air) temperature, the average cooling temperature of SNF@TiO under direct sunlight reached 11.5 °C. Meanwhile, the outdoor subambient (: 900 W·m, PE-covered air) average temperature drop of SNF@TiO reached 12.1 °C after UV (40 mW·cm) continuous radiation for 10 days (6 h per day), displaying highly stable radiative cooling properties. In addition, the SNF@TiO aerogel has good mechanical elasticity and thermal insulation properties. This study offers great potential for silk fiber materials for outdoor radiant heat management.
白天辐射制冷通过反射阳光和辐射热实现可持续的制冷效果。然而，发射器对阳光的吸收和寄生热增益会显著降低辐射制冷温度。为了提高中红外波段的光反射率和发射率，使用纳米丝和二氧化钛构建了具有高稳定性和高效辐射制冷效果的SNF@TiO气凝胶。气凝胶的分级结构储存了更多空气，从而降低了热导率（0.0333W·m·K）和寄生热增益。TiO在提高太阳能反射率和大气窗口发射率的同时，还具有优异的抗紫外线性能。SNF@TiO的平均太阳能反射率和平均红外发射率分别为89.4%和92.3%。与环境温度以下（：800W·m，PE覆盖空气）的温度相比，SNF@TiO在直射阳光下的平均制冷温度达到11.5°C。同时，在紫外线（40mW·cm）连续辐射10天（每天6小时）后，SNF@TiO的室外环境温度以下（：900W·m，PE覆盖空气）平均温度下降达到12.1°C，显示出高度稳定的辐射制冷性能。此外，SNF@TiO气凝胶具有良好的机械弹性和隔热性能。这项研究为用于户外辐射热管理的丝纤维材料提供了巨大潜力。
