Various Types of Silica Gel for Adsorption of Moisture and Water Drying
A Component that is capable of absorbing moisture and water is essential in the field of exporting the things which are more susceptible to a slight increase in humidity. Silica Gel is such a component, made up of Sodium Silicate and acts as a desiccant or drier with a microscopic pore size of 2.4 nanometers and a surface area of 700-800 square meters per gram which plays a main role in controlling humidity, as it has a high affinity to absorb water molecules from the surroundings. Also, Silica Gel has an infinite life because of its ability to absorb and Un-absorb the moisture; therefore it can be reconditioned and reused. Silica Gel is inert and has no volatile components.
Preservation in compressed air systems is attained only through Silica Gel desiccant. Since Silica Gel has the ability to convert from anhydrous state to a hydrous state; it is doped with moisture indicators such as Methyl violet & Cobalt Chloride. Because of the impregnation of such indicators Silica Gel Desiccant exists in different colors, as a result of the absorption of moisture and water.
Silica Gel can exist in both the Silica Gel bead form, as well as Silica Gel crystal form. Silica Gel is a colorless solid, which is odorless and often interchangeable with silica xerogel which gives a granular form, which is purified and processed to attain the Silica Gel bead form. To indicate the absorption of moisture, visually chemical indicators are impregnated in it, therefore the various colored form of Silica Gel beads are available, depending on the absorption capacity of each. Blue Silica Gel crystals are developed by the coagulating the solution of silica acid. Silica Gel crystals are highly efficient, due to the internal surface of about 800mz.
Silica Gel Blue
Silica Gel on transfusion with Cobalt Chloride changes to Silica Gel blue in dry condition, but when it becomes hydrated, it changes to Silica Gel Pink. It absorbs 5% of moisture and shows color variation depending on the absorption of moisture, i.e from blue to purple and to light red. Therefore, it is used as a desiccant in avoiding humidity damage. Silica gel blue is also used as a Transformer breather as well as in Chemical Industries.
Silica Gel Orange
Since, Silica Gel blue was found to be hazardous and is presently replaced with Silica Gel Orange, with an alternative indicator methyl violet. In dry condition, Silica Gel orange remains in orange color, whereas changes its color to green when hydrated. It absorbs up to 2% of moisture and shows color variation depending on the absorption of moisture, i.e from light brown-yellow to light brown green and then to blackish green. Therefore, it is used in the field of medicines, leather, and electrical appliances. Silica Gel orange is also used in the Refrigeration and purification of power and air.
Silica Gel White
When Silica Gel is not transfused with and indicating agents, it exists in the Silica Gel white form, which has an absorption of 5% of moisture and shows color variation depending on the absorption of moisture, i.e from white to semi-transparent and then to non-transparent. Therefore, it is used as a catalyst carrier, rust inhibitor and also as a gas drier. Silica gel white is also used in Power industries as well as for the drying of flowers and seeds.