Multiphase reaction spinning of high-temperature resistant weavable SiO₂-Kevlar hybrid aerogel fibers

Advanced aerogel fibers possess numerous advantages amalgamating the attributes of aerogels and fiber materials, rendering them invaluable in the realm of thermal management and regulation. However, the achievement of robust mechanical properties and increased temperature stability is still a major challenge for the majority of aerogel fibers. Herein, SiO₂-Kevlar hybrid aerogel fibers with bionic core–shell structure were prepared by reaction spinning and weaved into fabric. Kevlar nanowires dispersion is pumped into a bath comprising a self-synthesized silica sol, which facilitates the hybridization of biphasic aerogels through the gel reaction. Precise control over the diameter (200–800 μm) and structure of the wet gel fibers was achieved through meticulous adjustment of the spinning solution composition and spinning parameters. Subsequent freeze-drying process facilitates the formation of a core–shell hybrid structure, in which the SiO₂ aerogel layer effectively encapsulate the Kevlar aerogel core fiber. Taking full advantage of the mechanical properties of the Kevlar core fiber, the resulting SiO₂-Kevlar aerogel fibers exhibit commendable weaving characteristics (51.8 MPa). Furthermore, SiO₂-Kevlar aerogel fabrics exhibit enhanced thermal insulation characteristics with a thermal conductivity of 0.037 W/(m·K). As a result of the presence of external SiO₂ aerogel layer, the overall temperature resistance performance of the SiO₂-Kevlar fabric reach up to 700 °C.