A general principle of reducing the thermal conductivity of nano鄄superinsulating materials is proposed
in view of microstructure and ingredient factors. The SiO2 and SiO2鄄Al2 O3 nano鄄superinsulating materials with con鄄
trolled pore morphology were synthesized. It is found that the SiO2 and SiO2 -Al2 O3 nano鄄superinsulating materials
possess uniform mesoporous porous structure. The addition of nano Al2 O3 particles improves the thermal stability of
SiO2 material and the pore network is preserved and the thermal conductivity is 0. 02 W/ (m·K) at room temperature.
The stabilization mechanism of SiO2 nano鄄superinsulating materials by doping with Al2 O3 nanoparticles under high
temperature was investigated.