3D porous polymer film with designed pore architecture and auto-deposited SiO2 for highly efficient passive radiative cooling

By Bo Xiang, Rui Zhang, Yanlong Luo, S. Zhang, Lei Xu, Hui-hua Min, Shaochun Tang, Xiangkang Meng. 2021

394 citations recorded by the source corpus.

Abstract Passive radiative cooling (PRC) is the most promising technique to address future cooling requirements as it cools a surface without any energy input by reflecting sunlight and radiating heat, which will have a great impact on the global energy landscape. Here, we report a significant advance toward the design and fabrication of a novel hybrid material for outdoor PRC based on three-dimensionally porous cellulose acetate (3DPCA) film with rationally designed pore sizes centered at ~5 µm and auto-deposited resonant polar dielectric SiO2 microspheres. The side of 3DPCA/SiO2 film with enriched SiO2 shows both ultrahigh average solar reflectance R solar of ~96% and enhanced average infrared emittance e IR of ~95%, reaching up to the state-of-the-art levels. Especially the e IR value is greater than that of the reported solid polymer film with randomly distributed SiO2 microspheres (93%). The excellent PRC capability is further demonstrated by outdoor tests where practically attainable cooling temperatures are ~8.6 °C for nighttime and ~6.2 °C for daytime. The performance equals or surpasses that of state-of-the-art PRC designs, while the developed technique offers paint-like simplicity for low-cost and large-scale production. Owing to its superior PRC capability and scalability, this composite film is of great potential for promoting radiative cooling as a viable energy technology.

Subfields: Building and Construction, Civil and Structural Engineering, Environmental Engineering

View Paper: https://www.semanticscholar.org/paper/ae19401f7e4d4daa4ec819db8fa6fb57dcfe1818