Muscular Kevlar aerogel fibers appealing to thermal insulation with a symbiotic core-sheath structure

High-performance aerogels offer a broad application prospect owing to their various features such as high specific surface area and attractive thermal insulation . However, their porous structure confers weak mechanical properties to aerogels. The strategy of coaxial wet-spinning was implemented to strengthen Kevlar aerogel fibers and improve their usability. Prepared Kevlar aerogel fibers have a symbiotic core–sheath structure, with a blurred division between core and sheath. In addition, the breaking stress of Kevlar aerogel fibers can reach 2.6 MPa, which is four times that of the core, presenting a significant improvement in tensile strength compared to those in previous studies. Moreover, Kevlar aerogel fibers exhibit superior thermal stability, which is inherited from Kevlar fibers, and decomposed after 480 °C. Moreover, their high porosity and high specific area (∼400.5 m 2 ·g −1 ) endow them with outstanding thermal insulation properties. When fabrics woven from these fibers are exposed to a 300 °C hot plate, the temperature on the surface can be 110 °C lower, resulting in a significant temperature gradient of 83 °C·mm −1 . In total, the resultant Kevlar aerogel fibers with a symbiotic core–sheath structure are used as fillers for protective clothing or fire insulation blankets and similar items.