Yang Meng, Zou Weizhi, Guo Jing, Qian Zhenchao, Luo Heng, Yang Shijia, Zhao Ning, Pattelli Lorenzo, Xu Jian, Wiersma Diederik S
Beijing National Laboratory for Molecular Sciences, CAS Research/Education Center for Excellence in Molecular Sciences, Laboratory of Polymer Physics and Chemistry, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. China.
University of Chinese Academy of Sciences, Beijing 100049, P. R. China.
ACS Appl Mater Interfaces. 2020 Jun 3;12(22):25286-25293. doi: 10.1021/acsami.0c03897. Epub 2020 May 20.
Energy-saving cooling materials with strong operability are desirable for sustainable thermal management. Inspired by the cooperative thermo-optical effect in the fur of a polar bear, we develop a flexible, superhydrophobic, and reusable cooling "skin" by laminating a poly(dimethylsiloxane) film with a highly scattering polyethylene aerogel. Owing to its high porosity (97.9%) and tailored pore size of 3.8 ± 1.4 μm, it can achieve superior solar reflectance (̅ ∼ 0.96) and high transparency to irradiated thermal energy (τ̅ ∼ 0.8) at a thickness of 2.7 mm. Combined with the low thermal conductivity (0.032 W m K) of the aerogel, the cooling skin exerts midday sub-ambient temperature drops of 5-6 °C in a metropolitan environment, with an estimated limit of 14 °C under ideal service conditions. Our generalized bilayer approach can be easily applied to different types of emitters, bridging the gap between night-time and daytime radiative cooling and paving the way for more cost-effective and scalable cooling materials.
具有强可操作性的节能冷却材料对于可持续热管理而言是很有必要的。受北极熊皮毛中协同热光效应的启发，我们通过将聚二甲基硅氧烷薄膜与高散射聚乙烯气凝胶层压在一起，开发出一种柔性、超疏水且可重复使用的冷却“皮肤”。由于其高孔隙率（97.9%）和3.8±1.4μm的定制孔径，在2.7mm的厚度下，它能够实现卓越的太阳反射率（̅ ∼ 0.96）和对辐射热能的高透明度（τ̅ ∼ 0.8）。结合气凝胶的低导热率（0.032W m K），这种冷却皮肤在大都市环境中中午能使温度比环境温度低5 - 6°C，在理想使用条件下估计极限可达14°C。我们的通用双层方法可以轻松应用于不同类型的发射器，弥合夜间和白天辐射冷却之间的差距，并为更具成本效益和可扩展的冷却材料铺平道路。
