Electrospinning of SiO2-based composites embedded TiO2 nanoparticles with ultra-strong suppression of radiative heat transfer

Fibrous aerogel composites have attracted considerable attention in the field of insulation materials due to their low thermal conductivity and elasticity. However, they cannot meet the thermal insulation performance under practical application conditions due to their high infrared radiation transmittance and limited thermal stability. A novel strategy for embedding anatase TiO2 nanoparticles in SiO2 nanofibers was reported herein. TiO2 nanoparticles embedded in SiO2 nanofibers with bead-on-string structures were prepared through electrospinning, which leads to enhanced binding force between nanofibers and opacifier nanoparticles and uniform dispersion of opacifier in nanofibrous aerogel composites. Combined with freeze-drying technology, nanofibrous aerogel composites with the lamellar structure were prepared, which possessed ultra-low density of 5.8 mg/cm3 and superior compression strength (6.71 kPa at 40% strain) and fast recovery after compression. In addition, the obtained aerogel composites exhibited low infrared transmittance (60% at 3 µm), thermal conductivity (0.0257 W/mk at room temperature), splendid flame-retardant properties, and thermal insulation properties. The combined structural stability and low infrared transmittance offer an ideal candidate for thermal insulation under extreme conditions.