Yan Xiantong, Yang Meng, Duan Wenhui, Cui Hongzhi
Key Laboratory for Resilient Infrastructures of Coastal Cities (MOE), College of Civil and Transportation Engineering, Shenzhen University, Shenzhen 518060, China.
Department of Materials Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, China.
ACS Nano. 2024 Oct 8;18(40):27752-27763. doi: 10.1021/acsnano.4c10659. Epub 2024 Sep 25.
Electricity consumption for building cooling accounts for a significant portion of global energy usage and carbon emissions. To address this challenge, passive daytime radiative cooling (PDRC) has emerged as a promising technique for cooling buildings without electricity input. However, existing radiative coolers face material mismatch issues, particularly on cementitious composites like concrete, limiting their practical application. Here, we propose a cementitious radiative cooling armor based on a particle-solid transition architecture (PSTA) to overcome these challenges. The PSTA design features an asymmetric yet monolithic morphology and an all-inorganic nature, decoupling radiative cooling from building compatibility while ensuring UV resistance. In the PSTA design, nanoparticles on the surface serve as sunlight scatterers and thermal emitters, while those embedded within a cementitious substrate provide build compatibility and cohesiveness. This configuration results in enhanced interfacial bonding strength, high solar reflectance, and strong mid-infrared emittance. Specifically, the PSTA delivers an enhanced interfacial shear strength (0.93 MPa), several-fold higher than that in control groups (metal, glass, plastic) along with a cooling performance (a subambient temperature drop of ∼6.6 °C and a cooling power of ∼92.8 W under a direct solar irradiance of ∼680 W/m) that rivals or outperforms previous reports. Importantly, the design concept of the PSTA is applicable to various particles and solids, facilitating the practical application of PDRC technology in building scenarios.
建筑制冷的电力消耗在全球能源使用和碳排放中占很大一部分。为应对这一挑战，被动式日间辐射制冷（PDRC）已成为一种很有前景的无需电力输入即可为建筑物制冷的技术。然而，现有的辐射冷却器面临材料不匹配问题，尤其是在混凝土等水泥基复合材料上，这限制了它们的实际应用。在此，我们提出一种基于颗粒-固体转变结构（PSTA）的水泥基辐射冷却护层，以克服这些挑战。PSTA设计具有不对称但整体的形态和全无机性质，在确保抗紫外线的同时，将辐射冷却与建筑兼容性脱钩。在PSTA设计中，表面的纳米颗粒充当阳光散射体和热发射体，而嵌入水泥基基材中的纳米颗粒则提供建筑兼容性和内聚性。这种结构导致界面结合强度增强、太阳反射率高和中红外发射率强。具体而言，PSTA提供了增强的界面剪切强度（0.93MPa），比对照组（金属、玻璃、塑料）高出几倍，同时还具有制冷性能（在约680W/m的直接太阳辐照度下，环境温度下降约6.6°C，制冷功率约92.8W），可与之前的报告相媲美或更胜一筹。重要的是，PSTA的设计理念适用于各种颗粒和固体，便于PDRC技术在建筑场景中的实际应用。
