Graphene is a Nobel Prize winning discovery, with promise to be a super-material and the potential to cause a change in industry the likes of which has not been seen since the industrial revolution. But what is graphene, what is a super-material, and how will it affect you?
The structure of graphene is that seen in the picture; hexagons in a honeycomb formation, made of carbon atoms (the element fundamental to every living thing on Earth). When layers and layers of 1 atom thick graphene are stacked on top of one another, we get graphite (the stuff in our pencils). The first research into graphene began in 1947, when it was discovered that an electric current could pass through layers of graphene but it wasn’t actually isolated until 2004.
Graphene is one of my favourite scientific discoveries mainly because of the way in which it was finally isolated. Scientists had struggled for nearly 60 years, attempting to extract graphene from the bulk material graphite. On a Friday evening in 2004 two researchers at the University of Manchester decided to try it for themselves. They resorted to removing layers from a lump of graphite using…sellotape… Yes, you read that correctly. This huge scientific moment came about because of sellotape. On the sellotape was a single atom thick layer of graphene. What I love most about this approach was it’s simplicity, the way science used to be. Millions upon millions of dollars are pumped into the pharmaceutical and technology industries every year, but this founded with sellotape.
Why is graphene so impressive? Graphene is the first 2D material. It has unusual electronic properties, and the potential to be used in many areas of scientific research. Graphene is 200x stronger than steel, yet lightweight and flexible, and it is 1 million times thinner than a human hair! Graphene is also the world’s most conductive material. Applications of graphene include uses in energy production, the creation of new membranes (i.e. thin material through which only certain things can pass), biomedical applications, sensor and electronic technology amongst other areas of research.
So where can we expect to see graphene in the future? Graphene has ‘tunable’ properties, meaning they can be altered and manipulated to perform certain tasks. Here are three examples of research into the use of graphene:
- Medical applications: graphene can aid targeted drug delivery, improve brain penetration and can make ‘smart’ implants. For example, some drugs need to pass the BBB (blood/brain barrier) to reach their target. This area requires a drug to be hydrophobic (i.e. water hating) but this can be difficult to accomplish. Nanotubes, which are formed from sheets of graphene, can be tuned to the correct hydrophobicity and carry a drug through the barrier to the desired target without having to alter the drug! Also, carbon is inert to the body (i.e. does not interact/cause harm) so the drug could be masked and delivered successfully.
- Water purification: a mixture of the graphene structure and oxygen (graphene oxide), has been shown to successfully purify water which has been mixed with other liquids and even gases! (This finding astounds me). This is an example where graphene has been used as a membrane. The membrane itself is produced in a relatively simple way and could provide clean water for millions more people in the developing world. Graphene coatings could also be used in food packaging, preventing oxygen from getting to the food therefore making it last longer.
- Sensors: due to the small scale of graphene, it is possible to create ultra-sensitive senors. Every atom of a graphene sheet is exposed to the environment due to its 2D nature. As a result, this makes graphene ideal for sensing any changes in the environment, no matter how small. Therefore ultra-sensitive sensors which use graphene could be applied to water treatment works, air pollution testing and anywhere were chemical concentrations need to be monitored. It could even be used to detect the use of chemical warfare. The aim is to be able to detect just one molecule of a contaminate to the system in question, which is more advanced than current technologies.
Graphene is not yet widely used, but a few products have made it to commercial use. The first of these was a security smart packaging which uses a graphene based ink. It acts as a security tag on products. If the product is tampered with, an electric current which runs through the graphene, is interrupted and causes an alarm to be set off.
If graphene research continues at its current rate, it is likely we are at the start of witnessing a new industry boom. As graphene is readily available, not a finite resource, and can also be synthesised, this super-material may not only give rise to many new products but also a new industry with associated new jobs. There are not many materials in the world that can be so widely used, and across so many industries. The future of graphene is most definitely exciting.