SAXS study of isothermal sintering of silica aerogel

Isothermal sintering of SiO2 aerogels was followed by small angle X-ray scattering using synchrotron radiation. An improved treatment of SAXS data which takes into account the presence of fluctuations explains the discrepancy previously observed with He-pycnometric methods. The matrix density of the gel is shown to increase in several steps, first by a diffusion-controlled mechanism and then by viscous flow. © 1988