Highly thermally conductive PEEK-based bi-selective radiative cooling composites with isolated structure for outdoor thermal management

Abstract

Polyether ether ketone (PEEK) is a special engineering plastic that exhibits a range of valuable characteristics, including outstanding mechanical capabilities, thermal stability, and flame retardancy. Currently, in order to address the global energy and environmental crises, the development of passive daytime radiative cooling (PDRC) composites with emerging functions represents a crucial area of research. In this study, PEEK-based bi-selective radiative cooling composites (hydroxy boron nitride and aramid fibres/PEEK, i.e., HO-BN&AMFs/PEEK) are initially reported to be connected to energy conservation, which demonstrate remarkable performance with a temperature reduction of 8.28 °C below the ambient temperature in actual tests. Furthermore, the in-plane thermal conductivity of the composites is observed to be 5.95 W m⁻¹ K⁻¹, which is 25.87 times that of pure PEEK. BN-OH, which possesses a wide bandgap, strong scattering, and high phonon transfer speed as a filler, can endow the resulting composites with excellent PRDC and high heat conduction performance. In addition, the integration of porous AMFs enhances the Mie scattering and filler selectivity of the composites. The EnergyPlus simulation results indicate that the multi-functional HO-BN&AMFs/PEEK composites can achieve considerable energy savings when employed in the construction industry. It highlights the fact that this study provides a promising approach for developing PEEK-based PDRC materials.