A lightweight aramid-based structural composite with ultralow thermal conductivity and high-impact force dissipation

Material designs for safety protection are increasingly important due to ubiquitous impact damage and thermal hazard. Recent biomimetic architectures achieve extraordinary safeguards but exhibit a single-defense function, which remains a formidable challenge in mechanical-thermal-coupled protection. Herein, a lightweight composite (AFSG) with a shear stiffening gel (SSG)-filled aramid nanofiber (ANF) aerogel structure is developed through infiltration and lamination. Benefiting from the voids-SSG coexistence construction achieved by retaining massive microvoids in densified aerogel networks, AFSG exhibits ultra-low thermal conductivity (0.09 W m(-1) k(-1)) and high-impact force dissipation. Specifically, microvoids inside AFSG greatly block heat transfer and achieve a wide insulation temperature (-120 to 300 degrees C). SSG and the laminated-layout structure effectively attenuate 65%-79% of impact force through structure hardening, interlayer sliding, and intra-layer cracking. Such a versatile, lightweight structural composite is expected to defend against simultaneous mechanical impact and heat damage as an ideal candidate for next-generation protective materials applied in transportation, military, and aerospace fields.

Automated summary

In this study, a lightweight composite material with low thermal conductivity and high impact force dissipation is developed through infiltration and lamination. The versatile nature of this material makes it an ideal candidate for applications in transportation, military, and aerospace fields.