Graphene

Graphene is another allotrope of the element carbon and a newly discovered material which was first isolated in 2004. Graphene was first isolated from graphite, you may recall that graphite consists of stacked layers of carbon atoms arranged in layers of hexagons as shown in the image below. Each of these individual layers of hexagonal carbon atoms is in fact graphene! There only weak intermolecular forces between each of these layers of graphene or carbon atoms in graphite and so each of these layers can be easily separated from each other. The first samples of graphene were obtained by removing these single layers of these carbon hexagons from graphite using some very hi-tech stuff- sellotape!!

Graphene structure

Like graphite each carbon atoms in graphene forms three strong covalent bonds leaving one spare free electron. These free moving delocalised electrons are responsible for the excellent electrical conductivity of graphene. The three strong covalent bonds made by each carbon atom make graphene an incredibly strong material despite the fact that each graphene layer is only one atom thick; in fact each graphene layer is some 200 times stronger than steel by weight. The image below shows the individual layers or hexagon lattice of carbon atoms that makes up each graphene layer.

Uses of graphene

Graphene is one of the strongest substances known despite only being only one atom thick; it is an excellent thermal (heat) and electrical conductor, it is transparent and highly flexible. These properties seem like a scientists dream material and open up graphene to a mass of uses. Possible uses include:

• Its flexibility, excellent electrical conductivity and the fact its transparent open up the possibility of bendable, flexi electronic devices such as smart phones, TV and even wearable technology that could be woven into our everyday clothes and materials. Imagine a TV woven into your curtains or your clothes or one that you fold up and put into a drawer when not in use.


• Graphene is a promising alternative to indium tin oxide (ITO); the current standard transparent conductive material used in smart phone and computer touch screens. The flexibility of graphene will enable foldable and rollable touch screen displays. Graphene is much stronger and less brittle than ITO so no more worries about cracked and chipped smart phone displays. It is highly likely that the next generation of smart phones and computer displays will use this flexible and durable material.


• Graphene used in batteries can increases the life and charge and also reduce the recharge time these batteries. In the future we are bound to become more reliant on battery technology as economies move away from traditional energy sources such as fossil fuels; for example in the transport industry as cars, buses, lorries and even aeroplanes will become more dependent on electrical power. So graphene use in batteries will result in batteries that are lighter; hold more power and charge quicker.


• Graphene woven with other materials could provide strong lightweight composite materials e.g. bullet-proof and stab-proof vests:


• Exceptional Strength-to-Weight Ratio: Graphene is one of the strongest materials known, hundreds of times stronger than steel by weight. This means a lighter vest could potentially offer comparable or even superior protection from bullets and other projectiles.


• Lightweight and Flexible: Compared to traditional bulletproof materials like Kevlar, graphene is much lighter and more flexible. This would lead to more comfortable, wearable and manoeuvrable body armour.


• High Tensile Strength: Graphene is strong enough to withstand significant pulling and tearing forces before breaking, which is important for dissipating the energy of a projectile such as a bullet or even a knife and protecting the person under attack.


• The flexibility and chemical stability of the next generation of electronic devices which will likely use graphene allows for the development of new materials for medical uses, particularly in the field of small scale nano-sensors and probes which doctors and surgeons could insert into the human body, these nano-probes and sensors would be able to move freely around inside the human body.


• Another area of current research is in the use graphene in solar cells. Graphene is an excellent material for converting solar energy into electrical energy and solar panels made from graphene are much more efficient than those being currently used. These solar panels would also be transparent.


• Filters made from graphene are able to purify water efficiently and this could increase the amount of clean water available to billions of people in many countries.


• Graphene would make an ideal paint, it flexible, thin and very strong and would easily block water and oxygen and so prevent corrosion in metals.

You may be wondering why then is graphene not more widely used since it has so many amazing properties? At present graphene is expensive to produce in large quantities and to a high quality. However once these problems are overcome there may be a revolution in many areas using this material.

Key points

• Graphene is a newly discovered allotrope of carbon, it was first isolated in 2004, by isolating individual hexagonal layers in graphite.


• Graphene's structure consists of a single layer of carbon atoms arranged in a hexagonal lattice, with each carbon atom forming three strong covalent bonds.


• Graphene is incredibly strong; 200 times stronger than steel by weight; an excellent electrical and thermal conductor, transparent and highly flexible.


• Graphene has many potential applications, including flexible electronics, improved batteries, strong composite materials, advanced medical sensors and probes, more efficient solar cells and corrosion-preventing paints. However current limitations including the high cost of large-scale, high-quality production are limiting its wide-scale use, however these problems are likely to be overcome in the future. Apple for example has started using graphene in its latest 2025 iPhones though the use of graphene in other smart phones and electronic devices will likely increase as the technology evolves.

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