The porous texture of silica alcogels prepared under basic or acidic conditions was studied by thermoporometry. Wet gels were subjected to a pressure and temperature at which the solvent becomes a superfluid and then cooled to room temperature. Study of these samples by thermoporometry shows that the thermal treatment results in an increase of mesopore radii and volume and in a disappearance of microporosity. Measurements of the alcogel and aerogel shrinkage allow determination of macroporosity. After heat treatment in the autoclave the latter decreases strongly for gel prepared under acidic catalysis.
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Ceramics and Composites
- Condensed Matter Physics
- Materials Chemistry