What is Silica Gel?

What is Silica Gel? Commonly used in the healthcare and electronics industry and packed in a small white or transparent packaging, the moisture absorber is an amorphous form of silicon dioxide with atoms of an irregular framework. The absorbers contain nanometer voids spaces and a tridimensional structure of oxygen and silicon atoms. The liquid or gas material that fills the void or pores is called silica gel xerogel. Silica Gel is usually shaped and manufactured into a granular form. Chemicals added to form indicating absorbers that allow a change colour after it’s saturated.

Properties of Silica Gel

The desiccants absorb moisture due to their high surface area of around 800 m2/g. The desiccant’s physical property makes it ideal as a drying agent used to protect various goods and products against corrosion, contamination, spoilage, and mold growth. In loose bulk or packets for different degrees of humidity detection and control purposes, silica gel is differentiated into three different colours: white, blue, and orange.

Difference Between White, Orange, and Blue Silica Gel

White Silica Gel

A non-indicating moisture absorber, like its name suggests, does not change in colour even after saturation. A method to identify its saturated limit would be to measure the absorber by its weight or using a humidity indicator card.

Orange Silica Gel

Also known as Envirogel, the desiccants have an element for indication called methyl violet, capable of changing colour from orange to green/colourless once saturated with moisture. Although it has some medicinal merits, it is not safe for consumption.

Blue Silica Gel

On the other hand, this moisture absorber incorporates cobalt chloride, allowing it to change its colour from blue to pink once saturated fully with moisture. Cobalt chloride is toxic and not recommended to use with food products.

Applications of Silica Gel

The presence of moisture may encourage mould growth and decreases shelf life in food packaging, highly sensitive goods such as electronics are easily damaged by condensation. Silica Gel used as a drying agent in packaging has several benefits. When filled in desiccators, the desiccant will dry the air in industrial compressed air systems. The absorber will remove moisture from the air intake before entering the sealed container. They are commonly used as a preservative to control relative humidity in places like libraries and museums. Other applications include cameras and fish oil packaging.

Here is a video about our Desiccant Bags.