Nie Shijin, Bai Lizhan, Lin Guiping, Guo Yuandong, Yuan Kang, Zhang Yunfei, Lan Hongxiang, Su Shuai, Qi Guiguang, Wang Mengyang
Laboratory of Fundamental Science on Ergonomics and Environmental Control, School of Aeronautic Science and Engineering, Beihang University, Beijing 100191, P. R. China.
International Innovation Institute, Beihang University, Hangzhou 311115, P. R. China.
ACS Appl Mater Interfaces. 2025 Aug 27. doi: 10.1021/acsami.5c14348.
Passive daytime radiative cooling (PDRC) technology relies on reflecting solar visible light that carries high energy and radiating surface heat to a low-temperature cold background in the long-wave infrared band, thereby achieving clean energy-saving cooling. However, the irreversibility of high flux heat flow is often present in practical applications, resulting in the inability to maximize the cooling effect produced by radiative cooling. In this study, we developed an integrated radiative cooling (RC) film with high thermal conductivity for efficient cooling (DPHA film) by strategically constructing internal thermal channels within the RC interface. Compared to the indoor chamber temperature, the DPHA film, with its superior optical properties (reflectivity ∼ 0.96, emissivity ∼ 0.98), yielded a maximum temperature difference of 17.5 °C and an average difference of 13.2 °C under solar intensity of 977 W m. The cooling effect was 8.5 °C lower than commercially available highly reflective aluminum paint and 5.2 °C lower than a comparable cooler. Thermal conductivity tests showed that the DPHA film possessed high out-plane thermal conductivity (0.755 W m K), which facilitated the radiative dissipation of surface heat via forming a thermal gradient with the environment. After 30 days of continuous strong UV irradiation experiments, the obtained film showed favorable optical properties and aging resistance. DPHA film as a new radiative cooler effectively improves the overall performance of the cooling, with good potential and scalability for outdoor applications. This provides a new way to develop radiative cooling materials that are efficient, cost-effective and easy to mass produce.
被动式日间辐射冷却（PDRC）技术依靠反射携带高能量的太阳可见光，并将表面热量辐射到长波红外波段的低温冷背景中，从而实现清洁能源节约型冷却。然而，在实际应用中常常存在高通量热流的不可逆性，导致无法使辐射冷却产生的冷却效果最大化。在本研究中，我们通过在辐射冷却（RC）界面内策略性地构建内部热通道，开发了一种具有高导热性的用于高效冷却的集成辐射冷却（RC）薄膜（DPHA薄膜）。与室内腔室温度相比，DPHA薄膜具有优异的光学性能（反射率约为0.96，发射率约为0.98），在977 W m的太阳强度下，产生的最大温差为17.5℃，平均温差为13.2℃。其冷却效果比市售高反射铝漆低8.5℃，比同类冷却器低5.2℃。热导率测试表明，DPHA薄膜具有高的面外热导率（0.755 W m K），这通过与环境形成热梯度促进了表面热量的辐射耗散。经过30天的连续强紫外线照射实验后，所得薄膜显示出良好的光学性能和耐老化性。DPHA薄膜作为一种新型辐射冷却器有效地提高了冷却的整体性能，在户外应用方面具有良好的潜力和可扩展性。这为开发高效、经济且易于大规模生产的辐射冷却材料提供了一条新途径。
