Silica Gel Desiccants

Silica Hydrogel Production and Properties: Silica gel is also known as aqua gel. Silica gel got that name because of its high moisture content. Silica gel contains 60 to 65 percentage of its weight. It is a combination of pure silicon dioxide and water. It is available as finely ground white powder or white clear crystals.

These products are generally called as synthetic amorphous silica gels. By reacting sodium silicate solution with an acid, we can produce silica hydrogel. sodium silicate solution is commonly known as water glass. It comprises a distribution of polymeric silicate anions with charge-balancing sodium cations.

Addition of a mineral acid destabilizes the silicate solution forcing the silicate polymers to form colloidal silica particles, known as a silica hydrosol (silica gel). The size of these silica hydrosol is typically 1.5 to 2.0 nm. However it depends on silica concentration, electrolyte level, amount of excess acid and temperature.

Silica gel is a known desiccant. It is widely using for industrial purposes. Colloidal silica particles are highly active. They continue to interact to form a solid close-packed structure with water, and  immobilized within the matrix.

Desiccants have ability to absorb water contents. The rigid translucent silica hydrogel is broken into pieces and then washed to remove excess acid and salt by-product. Industries such as cargo and packaging have more advantages with silica gel. They can store their bulk quantity of cargoes along with the desiccants to avoid moisture damages.

Once the required pore structure has been developed, the particles are then milled and classified to give carefully controlled particle size distribution with excellent filtration properties and high purity. Desiccants should be stored in a closed circumstance.