Silica gel density is determined by a number of factors. For instance, its density depends on its density of composite adsorbent, its moisture-absorbing capacity, its adsorption capacity, and its hydrophobicity. These parameters are also affected by the preparation procedure of silica aerogel.
For instance, silica gel adsorbs up to 37% of its own weight in moisture. In high humidity environments, its capacity for adsorption increases dramatically.
Besides its adsorption capacities, silica aerogel has an impressive hydrophobicity. This property is important because it is a great adsorbent for organic compounds.
For this reason, it is very useful as a desiccant. Its drying and water adsorption properties make it suitable for use in humidities as high as 40%. And it can be reused multiple times without loss of efficiency.
Silica aerogel is a good adsorbent for organic compounds. Its adsorption capacity is higher than that of active carbon. Also, its porosity is highly favorable, especially for organic compounds.
Silica aerogels are prepared by a process involving a water-glass-based adsorbent, silylation, and cooling to ambient temperature. After drying at atmospheric pressure, the density of the prepared aerogel was measured. The density was found to be 0.30 g/cm3 and the BET surface area to be 838.6 m2/g.
Silica aerogels are used as adsorbents for the removal of moisture from gas streams. They can be used for the drying of industrial compressed air systems, as well as for the moisture protection of gas mask canisters.