Ultralight Alumina Nanowire Ceramic Aerogels via Clay-Like Shaping for Thermal Insulation under Extreme Conditions

Achieving high-precision shaping in ceramic aerogels remains a formidable challenge owing to the intrinsic brittleness and weak mechanical strength of ceramics. Herein, aerogels constructed from 1D nanowires are designed, in which dynamic hydrogen bonding enables a clay-like precursor to be freely shaped into arbitrary geometries. The resulting nest-like ceramic nanowire aerogels (CNWAs) exhibit enhanced robustness, retaining a compressive strength of 1.2 MPa even after exposure to extreme conditions of 1200°C and -196°C, and showing pronounced resistance to mechanical impact. Moreover, CNWAs achieve a density as low as 0.08 g cm^-3, a thermal conductivity of 0.028 W m^-1 K^-1, and excellent high-temperature resistance up to 1300°C. These superior comprehensive properties stem from the entangled nanowire network, which effectively dissipates both thermal and mechanical stresses. This work provides a generalizable strategy for designing aerogels with complex architectures and outstanding performance, opening new avenues for the development of next-generation ceramic aerogels.