Silica gel is a type of adsorbent. It is known for its drying and heat storage properties. These characteristics make it useful as a desiccant, drying agent and moisture control.
There are three types of silica gel. They are macroporous silica gel, fine pore silica gel and low density silica gel. The molar mass of these gels is about 0.7 grams per millilitre.
Sodium silicate is the source of the basic ingredient of silica gel. It is acidified to form a gelatinous precipitate. This precipitate is then washed. When the gel is exposed to air, it dehydrates and turns colorless.
Silica gel is available in polymeric, irregular, or monomeric forms. It is widely used in selective herbicide separation.
Silica gel is also used to provide moisture proof and anti-sticking properties for plastic films and paints. It has the capacity to adsorb moisture in high humidity environments. Besides, it is a non-reactive and thermally stable compound. In general, it can be reused many times without losing its efficiency.
Silica gel is commonly found in a tiny paper packet. In addition, it is used in diagnostic test strips and inhalation devices. It is also used to dry air in industrial compressed air systems.
It can be applied on glass, aluminium and plastic sheets. Since it has moisture-proof and heat-storing properties, it can be used as a refractory binder in manufacturing processes. Besides, it is also used in pulp treatment agents. And it is applied to high frequency waveguides to reduce relative humidity.