Thermally insulating and wave-transparent magnesium aluminum spinel nanofibers applied from −196 to 1600 °C

The rapid development of aerospace requires radomes to achieve the effect of thermal insulation and electromagnetic wave transmission. However, traditional interlayer materials in radomes for thermal insulation are eligible to structural collapse and brittle fracture at high temperatures. Here, MgAl 2 O 4 nanofibers (MANFs) are successfully fabricated from a quasi inorganic/block-copolymer chain segment via molecular design. The MANFs have a laminated geometrical form with tiny pore size, high porosity, and frameworks connected by nanoparticles, resulting in both ultralow density and thermal conductivity that endow them with excellent thermal insulation properties. The MANFs possess unprecedented elasticity from –196 to 1600 °C with a recoverable compression strain of up to 80 % and excellent fatigue resistance for long-term use, which exceeds the reported results of existing fibers. Excitingly, the low dielectric constant enhances the electromagnetic wave transparency of MANFs, making them suitable as a signal transmission material in radomes. The tremendous potential of MANFs promotes the development of thermal insulators with wave-transparent properties used in extreme environments.