Fig. 4.

Nitrogen isotherm of the silica aerogel product. The isotherm exhibited a type-IV curve and the measurement indicated that its specific surface area was 813 m² g⁻¹, pore volume was 0.78 cm³ g⁻¹, and average porosity was 4.2 nm. After the epoxy modification, these dropped to 471 m² g⁻¹, 0.48 cm³ g⁻¹, and 3.7 nm.