Temperature‐Sensitive Colored Radiative Cooling Materials with Efficient Cooling Performance

Abstract

Several daytime radiative cooling materials involving various structures and composed using multilayer thin films, polymers, and nanoparticles have been fabricated and studied. However, their surface is of white or some other monotonous color because of the requirement for most of the incident sunlight to be reflected. A temperature‐sensitive colored radiative cooling (TCRC) material that provides efficient cooling while preserving the aesthetic properties of the surface has been developed. The TCRC material is manufactured as a bilayer structure for efferent cooling applied on a colored radiative cooling emitter. The bottom layer reflects as much light as possible using polyvinylidene fluoride and alumina particles, and the top layer uses a thermochromic color pigment to display color. The optical properties of the TCRC material, in response to temperature changes, are evaluated and its efficient cooling ability is confirmed. The temperature cooling is confirmed for TCRC emitters of yellow, magenta, and blue colors, using an outdoor temperature measurement system, and it is experimentally confirmed that the TCRC emitters provide more cooling (by 1.75, 2.67, and 4.31 °C, respectively) than conventional paint of the same color.

Making color display cool: An electrochemical self-cooled dynamic structural color device

“…There are not yet EC devices that can realize reversible color-changing while preserving high solar reflection. 14,17,[39][40][41][42][43][44][45][46][47][48][49] .…”

Self‐Adaptive Colored Radiative Cooling by Tuning Visible Spectra

“…[25,26] Hence, passively regulating thermal radiation based on temperature response can be an efficient approach to reducing the energy consumption of buildings in the thermal management processes. [27,28] For example, Son et al proposed colored temperature-sensitive radiative cooling emitters, [29] which can provide more cooling of 1.8, 2.7, and 4.1 °C than conventional paint. Park et al fabricated an adaptive radiative cooling coating based on hollow SiO 2 , PDMS, and thermochromic pigment, [30] which can absorb solar radiation at low temperatures and exhibit radiative cooling at high temperatures above 40 °C.…”

Flexible and Dual‐Sided Available Colored Films for Efficient Daytime Radiative Cooling

“…The key issue to design effective colored PDRC material is to lower the unnecessary solar absorption and improve emission across the atmospheric transparent window. [ 31,32 ] Hierarchically porous materials with light‐scatting air voids have excellent solar reflectivity, [ 7,33–35 ] and randomly packed SiO 2 with a right particle size and disorder can achieve a high reflectivity. [ 36 ] It has been demonstrated that the polymer‐based hybrid metamaterials with randomly distributed SiO 2 microspheres exhibit excellent PDRC capacity due the high emissivity across the atmospheric transparent window.…”

“…[10,23,30] The key issue to design effective colored PDRC material is to lower the unnecessary solar absorption and improve emission across the atmospheric transparent window. [31,32] Hierarchically porous materials with light-scatting air voids have excellent solar reflectivity, [7,[33][34][35] and randomly packed SiO 2 with…”