Flexible, transparent, flame-retardant cellulose/silica–aluminum composite aerogel films for thermal management

As the global climate tends to become more extreme, high-performance thermal management materials are important for the comfort of human existence. Cellulose-based aerogels have become a hot research hotspot due to their abundant raw materials and good mechanical properties. Herein, cellulose/silica–aluminum composite aerogels (CSAL) with organic–inorganic structures were obtained by in situ formation of silica–aluminum aerogel nanoparticles via a two-step sol–gel process, which was prepared by dissolving cotton pulp in the ionic liquid. Related properties are investigated with Fourier transform infrared spectroscopy, scanning electron microscopy, ultraviolet-visible spectrometer, N₂ adsorption, compression tests, thermogravimetric analysis, and ignition tests. The resulting CSAL samples have low density (0.112–0.133 g/cm³), high specific surface area (252.65–464.02 m²/g), good mechanical properties, and excellent transmittance (>60 %). Thus, the as-prepared high-performance cellulose/silica–aluminum composite aerogel films with flexible, transparent, flame retardant, which have great potential for application in lightweight energy-efficient buildings, household equipment and other fields requiring thermal insulation.