Uniform pore structure silica aerogel powders prepared by pore repair method

Nowadays, the rapid preparation of silica aerogel powders by ambient pressure drying (APD) method has been widely studied. However, the internal pore structures of the aerogel powders prepared by the conventional rapid aging method (CM) are difficult to be controlled due to the increase in the particle agglomeration and the macropores structure. In this research, a rapid way was introduced to control the microstructure of the silica aerogel powders through pore repairing (PR) method in the aging process. The bulk gel and gel particles were double aged to enhance the skeleton structure of gel particles. The new silica nanoparticles were formed, and filled in the macropores of gel particles by adhesion or deposition in the networks of gel particles during the late ageing process, the pore structure in the gel particles were uniform within just 2 h of aging. Under optimal ageing conditions, silica aerogel powders with low density (0.089 g/cm(3)), low thermal conductivity (0.0243 W/m K) and high specific surface (882 m(2)/g) was obtained through the pore repairing method. Pore repairing method in the aging process has certain research significance to control the pore structure of aerogel powders.

Automated summary

Nowadays, the rapid preparation of silica aerogel powders by ambient pressure drying (APD) method has been widely studied. However, the internal pore structures of the aerogel powders prepared by the conventional rapid aging method (CM) are difficult to be controlled. In this research, a rapid way was introduced to control the microstructure of the silica aerogel powders through pore repairing method in the aging process. Under optimal ageing conditions, silica aerogel powders with low density, low thermal conductivity and high specific surface was obtained through the pore repairing method.