Facile preparation of lightweight high-elastic celluous/SiO2 composite aerogel with outstanding thermal insulation performance

Silica aerogel, renowned for its ultra-low thermal conductivity, holds significantpotential as an advanced thermal insulation material. However, its practical application is hindered by limitations in strength and mechanical properties, particularly under harsh, high-temperature conditions, which compromise both mechanical resilience and insulation. To mitigate this, we synthesized silica nanofibers via electrostatic spinning and subsequently crafted thermally and mechanically robust cellulose fiber/silica nanofiber aerogel composites through freeze-drying. The resulting aerogel demonstrates remarkable physical properties: an ultra-lightweight bulk density of 1.3 mg/cm(3), low thermal conductivity (47 mW<middle dot>m(-)(1)<middle dot>K--(1) at 1000 degrees C), and high resilience. The internal fiber network is densely cross-linked, enhancing collapse resistance, structural stability, and rigid support. Mechanical testing revealed a high stress of 0.88 kPa at 80% compressive strain, which reached 1.02 kPa following 900 degrees C treatment. Thermal stability and insulation tests demonstrated the aerogel's ability to withstand extreme temperatures (no combustion under a 1,300 degrees C flame) and maintain effective thermal insulation while retaining good recovery at 600 degrees C. These findings indicate that the novel aerogel composites surpass traditional ceramic fiber aerogel materials in mechanical and thermal insulation properties at high temperatures, presenting widespread application potential in extreme high-temperature environments.