Emerging fabrication of ceramic nanofiber aerogel with the application in high-temperature thermal insulation, environment, and electromagnetic wave absorption

Ceramic nanofiber aerogels (CNFAs), built from ceramic fiber components, stand out for their multifunctional properties, including low density, low thermal conductivity, high porosity, compressibility, robust chemical stability, and resistance to high temperatures. The continuity of the building blocks overcomes the brittleness of ceramic aerogels and expands their applications, which makes them widely used in the fields of high-temperature thermal insulation, sound insulation, oil-water separation, seawater desalination, air filtration, and electromagnetic wave absorption. Among the current methods for preparing CNFAs, electrostatic spinning is a perfect method for producing reproducible micro-nanofibers. Direct electrostatic spinning combined with freeze casting makes it easy to prepare CNFAs with anisotropic properties, while chemical vapor deposition makes it easy to prepare aerogels with random structures. The method of solution blow spinning has advantages of high fiber productivity and low-voltage electric field relative to electrostatic spinning, and the atomic layer deposition depends on templates to produce films with formulated thickness. This review initially explores the fabrication methods of CNFAs, including electrostatic spinning, freeze casting, chemical vapor deposition, solution blow spinning, and atomic layer deposition. Subsequently, it delves into the novel applications of CNFAs in recent years in the fields of high-temperature thermal insulation, sound insulation, electromagnetic wave absorption, oil-water separation, seawater desalination, and air filtration. Moreover, the advancement of CNFAs with high-temperature thermal insulation, fire resistance, strong flexibility, and tensile properties opens up promising applications in aerospace, personal protective equipment, and flexible wearable devices in the future.