A physical barrier woven by flexible, adiabatic and structurally stable high-entropy nanofiber sponges for efficient surface protection

The surface of equipment under harsh conditions often requires protection from adiabatic ceramic fibers. However, the structural stability and flexibility of fibers are frequently compromised. Here, (LaCeNdSmEu) 2 Zr 2 O 7+δ , a defective high-entropy pyrochlore, was fabricated into flexible nanofiber sponges utilizing a simple saturated solution blow spinning method. The novel 3D lamellar sponges, containing numerous micropores woven by nanofibers, can achieve thermal insulation efficiently. Moreover, the defects and high-entropy effects inside nanofibers can further strengthen their structural stability. Furthermore, nanofiber sponges can remain flexible at -196–1350 °C. Even when burned by the flame, only 2-cm-thick sponges can reduce the heat source from 1350 to 285 °C. The smooth sintering process, low thermal conductivity (0.024–0.044 W/(m•K) at 28–500 °C), high long-term operation temperature (1350 °C), low density (14 mg/cm 3 ), excellent compression flexibility, and remarkable structural stability under various harsh conditions can endow nanofiber sponges with powerful surface protection capability.