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.