Aerogel fibers with ultrahigh porosity and ultralow density are promising candidates for personal thermal management to reduce the energy waste of heating an entire room, and play important roles in reducing energy waste in general. However, aerogel fibers generally suffer from poor mechanical properties and complicated preparation processes. Herein, we demonstrate hierarchically porous and continuous silk fibroin/graphene oxide aerogel fibers (SF/GO) with high strength, excellent radiative heating performance, and thermal insulation performance through coaxial wet spinning and freeze-drying. The hollow CA/PAA fibers prepared via a coaxial wet spinning process have multiscale porous structures, which are not only beneficial for the formation of an SF/GO aerogel core, but also help to improve the mechanical strength of the aerogel fibers. Moreover, the prepared aerogel fibers show comparable porosity and mechanical properties with those of hollow CA/PAA fibers. More importantly, GO can dramatically improve the infrared radiative heating properties, and the surface temperature is increased by 2.6 °C after exposure to infrared radiation for 30 s, greatly higher than that of hollow fiber and SF aerogel fibers. Furthermore, the integration of hierarchically porous hollow fibers and SF/GO aerogels prevents thermal convection, decreases thermal conduction, and suppresses thermal radiation, rendering the SF/GO aerogel fiber with excellent thermal insulation performance. This work may shed light on the heat transfer mechanism of the microenvironment between the human body and textiles and pave the way for the fabrication of high-performance aerogel fibers used for personal thermal management.
Keywords: aerogel fiber; graphene oxide; radiative heating; silk fibroin; thermal insulation.