Multifunctional protective aerogel with superelasticity over −196 to 500 °C

Protective materials that possess superelasticity and multifunctionality over a broad temperature range are urgently needed in various advanced applications. However, under harsh work conditions, the performance of current materials may largely deteriorate to lose protective functionality. Herein, we report a bidirectionally oriented multi-walled carbon nanotubes (MWCNTs)-reinforced chitosan carbon aerogel (CS-MWCNT) that possesses superelasticity, high electromagnetic interference shielding, thermal insulation, and infrared stealth at both low temperatures (such as liquid nitrogen) and high temperatures (such as alcohol flames). Highly oriented lamellar arch structures combined with an MWCNTs-reinforced carbon skeleton act as elastic segments to disperse the stress during compression and endow CS-MWCNT with the ability to recover to almost the original size after being compressed at −196–500 °C. The lamellar structures make CS-MWCNT thermally insulating and infrared stealth with a low thermal conductivity of ~ 0.03 W/(m·K). Furthermore, a high electromagnetic interference (EMI) shielding effect of 64 dB is realized via an absorption-dominant EMI shielding mechanism derived from the successive inherently conductive carbon lamella, and the EMI shielding performance is largely maintained after treatment under extreme conditions like low temperature, high temperature, as well as cyclic compression. This work provides a new strategy for the development of temperature-invariant multifunctional aerogels for harsh environment applications.