Ultralight and hyperelastic SiC nanofiber aerogel spring for personal thermal energy regulation

Multifunctionalization is the development direction of personal thermal energy regulation equipment in the future. However, it is still a huge challenge to effectively integrate multiple functionalities into one material. In this study, a simple thermochemical process was used to prepare a multifunctional SiC nanofiber aerogel spring (SiC NFAS), which exhibited ultralow density (9 mg/cm3), ultralow thermal conductivity (0.029 W/(m·K) at 20 °C), excellent ablation and oxidation resistance, and a stable three-dimensional (3D) structure that composed of a large number of interlacing 3C-SiC nanofibers with diameters of 300–500 nm and lengths in tens to hundreds of microns. Furthermore, the as-prepared SiC NFAS displayed excellent mechanical properties, with a permanent deformation of only 1.3% at 20 °C after 1000 cycles. Remarkably, the SiC NFAS exhibited robust hyperelasticity and cyclic fatigue resistance at both low (∼−196 °C) and high (∼700 °C) temperatures. Due to its exceptional thermal insulation performance, the SiC NFAS can be used for personal thermal energy regulation. The results of the study conclusively show that the SiC NFAS is a multifunctional material and has potential insulation applications in both low- and high-temperature environments.