Silicon dioxide, more commonly known as silica, has the chemical formula SiO₂. Silica is a compound consisting of an amalgamation of silicon and oxygen atoms, the ratio of which being two oxygen atoms bound to one silicon atom. Silica is part of one of the most bountiful and complex material groups on the planet, so much so that it makes up 12% of the earth’s crust.
In nature silica can be found in materials such as:
- Sand
- Quartz crystal
- Amethyst
- Flint
- Tridymite
- Cristobalite
- Agate
- Chalcedony
Silica nanoparticles can be manipulated into various forms with a multitude of uses. One form silica is used in is silica gel. Silica gel tends to be used as a desiccant (drying agent) due to it being highly absorbent. You will most likely have come across little packets of silica gel yourself, which tend to be found in items of clothing, food and many other goods to keep them from humidity deterioration in storage. Often, people throw these away but they can be reused in a plethora of ways such as:
- Reviving water-damaged devices
- Maintain the condition of collectables
- Protect important documents in long-term storage
- Ward off that musty old book smell
- Prevent the tarnishing of stored jewellery
Another form of silica is crystalline silica. As the name suggests, this is found in the crystalline form such as quartz and tridymite. Crist0obalite can be manufactured from quartz by heating it high temperatures (over 1000 degrees celcius). This high melting point elevates its value in the manufacturing world as a multi-use mineral.
Another benefit of crystalline silica is its inertia, meaning it does not react with other chemical. This makes it a particularly safe compound. Crystaline silica is used in most of the modern world from glass and ceramics to the railways and roads – even the vehicles we used to travel on them.
Uses for silica can also be found on a very small scale – silica nanoparticles can also be used in the formulation of paint to ensure longer lasting coatings, or amalgamated into 3D printing materials to alter the characteristics of the final product.
As a result of their low toxicity, silica nanoparticles are also employed widely in the medical sector. Other benefits for this use include their uncomplicated preparation and economical cost, alongside their porosity and thermal stability. These traits along with their large scale synthetic availability make for a vast functional capacity.
