What Happens When You Put Silica Gel in Water
Despite its name, silica gel isn’t a gel. It’s a desiccant, meaning it absorbs moisture and comes in the form of small, bead-like particles. The chemical formula for silica gel is SiO2 (silicon dioxide).
It is common in the packaging of products that absolutely must be kept dry, like electronics, shoes, and the like, due to its high absorption quality.
Due to these features, the following occurs when silica gel is placed in water.
What Happens When You Put Silica Gel in Water
- Adsorption of Water:
Silica gel is a desiccant, meaning it can absorb a large volume of liquid due to its porosity and internal surface area.
When it encounters water or most liquids, it rapidly adsorbs the water so much that it can absorb up to 40% of its original weight in water.
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- Heat Generation:
The adsorption of water by silica gel leads to an exothermic process of releasing heat, which is quite beneficial for the products in which it is stored. The heat released warms any liquid in its environment and consequently dries it up, keeping your products dry.
- Expansion:
The more water it absorbs, the bigger it becomes. So instead of dissolving like most compounds do, it does the opposite and sucks up all the water it can.
- Change in Appearance:
There are different types of silica gel. These variants react differently to water, but the initial premise is still the same (absorption). This indicates that silica gel contains moisture-sensitive colorants and may change color depending on how much liquid it has absorbed. The blue silica gel turns pink, while the orange turns green.
- Sustained dryness
Regardless of how much water it has absorbed, silica gel remains dry to the touch. If you want to reuse it, all you need to do is heat it to dry up all the absorbed liquid. This way, you do not have to worry about getting new ones whenever the other one has absorbed water.
Since it is lighter in weight than other absorbent materials, it is preferred for shipping. It also has a long shelf life and does not require any special handling precautions.
In addition, silica gel does not react with most other materials, which allows for safe storage, and except for very strong alkalis or hydrofluoric acid, most substances won’t cause any unwanted reactions with silica gel.
