Thermal Insulation Nanofiber Aerogels: A Journey from Structure Construction to Multifunctionalization

Aerogels are ideal materials for thermal protection due to their lightweight and porous properties; however, the intrinsic brittleness of conventional aerogels makes it difficult to overcome complex thermodynamic environments. Nanofiber aerogels (NFAs) are prepared from fiber components with a high aspect ratio, exceptional flexibility and controllable structures, which combined with excellent structural design can improve mechanical properties. This review presents recent advancements in thermal insulation NFAs, describes their heat transfer mechanisms, details the structural engineering strategies from the initial fiber component dimensions perspective, and explores potential applications across various fields. The influence of microstructures on heat transfer behavior of NFAs is first investigated, followed by four construction strategies from fiber components dimension: fiber reinforcement of granular aerogels, reconstruction from 1D fiber components, stacking from 2D fiber components, direct producing to 3D fiber structures, and analyze how these structures achieve a balance of NFAs mechanical-insulation properties. Subsequently, the potential applications of these structures, including thermal stability and flame retardancy, sound insulation, oil-water separation, air filtration, and electromagnetic shielding, are evaluated. Finally, challenges in constructing NFAs and anticipated future trends are discussed.