| dc.description.abstract | The experimental results of aging time and temperature on the textural properties of water-glass (sodium
silicate)-based silica aerogels are reported and discussed. Aging of the hydrogel for different times and temperatures
led to an ability to increase the stiffness and strength of the networks. These improvements enabled the gel to withstand
ambient pressure drying (APD) and, consequently, preserve the highly porous silica network without collapse. The
pore size and volume increased with increasing aging temperature and time, while the specific surface area decreased.
Monolithic aerogels with extremely low bulk density (~0.069 g/cm3), high specific surface area (820 m2g−1), large cumulative
pore volume (3.8 cm3g−1), and high porosity (~96%) were obtained by aging at 60 oC for 18 hours. Therefore,
easy synthesis of monolithic silica aerogels at ambient pressure is achievable using a relatively inexpensive silica precursor
(sodium silicate). | en_US |
