Camel skin-fat structure inspired MXene@PVA/PCC aerogel composite for efficient medium and low temperature infrared stealth

Abstract

Infrared stealth materials are in increasing demand with the development of infrared detection technology. However, most reported materials focus solely on emissivity control or temperature control, resulting in brief and less ideal infrared stealth effect. Herein, a double layer MXene@polyvinyl alcohol (PVA)/phase change capsules (PCC) aerogel composite inspired by the skin-fat structure of camel for infrared camouflage was successfully fabricated via a facile freeze-drying followed by spraying method. The PVA/PCC aerogel composite with high latent heat (155.2 J/g) and strong mechanical properties (772.6 kPa), obtained by an in-situ one-step method, is adopted as a temperature control layer, benefiting from the prominent thermal insulation of porous structure and effective heat absorption of PCC. The low emissivity (0.249) of the MXene layer on the surface of aerogel composite makes its radiation temperature recognized by the thermal imager much lower than its actual temperature. By integrating thermal insulation, heat absorption and emissivity reduction strategies, MXene@PVA/PCC aerogel shows no difference with the background in the infrared thermal imager (radiation temperature difference less than 10 °C), achieving superior infrared stealth for medium and low temperature scenarios, and provides novel ideas for developing more high-performance infrared stealth materials.