What is Silica Gel?
Published On: January 10, 2020 Revised On: May 4, 2023

What is Silica Gel?

What is silica gel

What is silica gel, and how does it work? The moisture absorber, which comes in a small white or transparent package and is commonly used in the healthcare and electronics industries, is an amorphous shape of silicon dioxide with an irregular structure of atoms. Nanometer void spaces and a tridimensional arrangement of oxygen and silicon atoms are found in the absorbers. Silica gel xerogel is the liquid/gas substance that fills the voids or pores. Silica gel is also shaped and manufactured as granules. Chemicals are used to create indicating absorbers, which cause a change in colour after it has been saturated.

Properties of Silica Gel

Because of their high surface area of about 800 m2/g, desiccants can absorb moisture well. Due to its high physical properties, the desiccant is an excellent drying agent for protecting various goods and products from corrosion, contamination, spoilage, and mould development. Silica gel is available in three different colours: white, blue, and orange, in loose bulk or packages for variable levels of humidity detection and control.

Difference Between White, Orange, and Blue Silica Gel

White Silica Gel

The colour of a non-indicating moisture absorber does not change until saturation, as the name implies. Measuring the absorber by its weight or using a humidity indicator card are two methods for determining its saturated limit.

Orange Silica Gel

The desiccants, also known as Envirogel, contain a colour indicator called methyl violet, which changes from orange to green/colourless when saturated with moisture. It is not healthy to consume, despite its medicinal properties.

Blue Silica Gel

This moisture absorber contains cobalt chloride that enables it to change colour from blue to pink when completely saturated with moisture. Since cobalt chloride is harmful, it should not be used in food.

Applications of Silica Gel

Moisture stimulates mould growth and shortens the shelf life of food packaging and highly sensitive products like electronics that are harmed by condensation easily. Silica gel has many advantages when used as a packaging drying agent. Desiccants can dry the air in industrial compressed air systems when filled in desiccators. Before entering the enclosed container, the absorber can extract moisture from the air intake. They are widely used as a preservative in areas like libraries and museums to regulate relative humidity. Cameras and fish oil packaging are examples of other applications.