Highly solar reflectance and infrared transparent porous coating for non-contact heat dissipations

Summary: Passive daytime radiative cooling (PDRC) can dissipate heat to outer space with high solar reflectance (R¯solar) and thermal emittance (ε¯LWIR) in the atmospheric transmission window. However, for the non-contact heat dissipation, besides the high R¯solar, a high infrared transmittance (τ¯L...

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Bibliographic Details
Main Authors: Meijie Chen, Dan Pang, Hongjie Yan
Format: Article
Language:English
Published: Elsevier 2022-08-01
Series:iScience
Subjects:
Online Access:http://www.sciencedirect.com/science/article/pii/S2589004222009981
Description
Summary:Summary: Passive daytime radiative cooling (PDRC) can dissipate heat to outer space with high solar reflectance (R¯solar) and thermal emittance (ε¯LWIR) in the atmospheric transmission window. However, for the non-contact heat dissipation, besides the high R¯solar, a high infrared transmittance (τ¯LWIR) is needed to directly emit thermal radiation through the IR-transparent coating to outer space. In this work, An IR-transparent porous PE (P-PE) coating with R¯solar= 0.96 and τ¯LWIR= 0.88 was prepared for non-contact heat dissipations. Under the direct sunlight of 860 W m−2, the IR-transparent coating obtained a 4°C lower heater temperature than the normal PDRC coating under the same condition. In addition, the spectral reflectance of the P-PE coating after immersing in air or water changed little, which showed excellent durability for long-term outdoor applications. These results indicate the P-PE coating can be a potential IR-transparent coating for non-contact heat dissipations under direct sunlight.
ISSN:2589-0042