Abstract:
Using silica sols as precursors, silica alcogel balls were prepared in the W/O emulsion composed of oil phase of Span80 and Tween85 as surfactants,
n-butanol as cosurfactant,
n-heptane as disperse medium, and aqueous phase of silica alcosols. In order to produce microscaled silica areogel balls, the silica alcogel balls were dried at ambient pressure. The resultant aerogel microballs were characterized by optical microscopy, SEM, TG-DTA and BET technique. The results show that the prepared silica aerogel microsballs which consist of silica nanoparticles of 10 nm are a novel kind of nanoporous structural materials with the porosity of 83.6%. They have a narrow pore size distribution in the range of 2-32 nm with an average value of 17 nm. The apparent density and specific surface area of microsballs are about 360 kg·m
-3 and 382.5 m
2·g
-1,respectively.