A radiative cooling structural material.

Li, Tian; Zhai, Yao; He, Shuaiming; Gan, Wentao; Wei, Zhiyuan; Heidarinejad, Mohammad; Dalgo, Daniel; Mi, Ruiyu et al. · Science · 2019

basic_science · Level V

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Abstract

Reducing human reliance on energy-inefficient cooling methods such as air conditioning would have a large impact on the global energy landscape. By a process of complete delignification and densification of wood, we developed a structural material with a mechanical strength of 404.3 megapascals, more than eight times that of natural wood. The cellulose nanofibers in our engineered material backscatter solar radiation and emit strongly in mid-infrared wavelengths, resulting in continuous subambient cooling during both day and night. We model the potential impact of our cooling wood and find energy savings between 20 and 60%, which is most pronounced in hot and dry climates.