Key facts about graphene
- Graphene is a human-made material with applications in almost every field.
- It is the thinnest material known, only one atom thick.
- It is ultralight, super strong, flexible, transparent, biodegradable and highly conductor.
Since graphene was discovered has attracted the attention of all industries due to its marvellous properties and uncountable applications.
Graphene is a combination of carbon atoms, like coal, graphite, and diamond. What makes the graphene so special is that it comprise only one-atom-layer thickness arranged in a perfect hexagonal lattice pattern. It is a single layer of carbon atoms tightly bounded, a two-dimensional structure with no third dimension. It is, therefore, the thinnest material ever created by man.
This material has many properties. Due to its crystalline structure and super strong bonds, it is 200x stronger than steel of the same thickness. It can be stretched up to 25%, conduct electricity 250x better than silicon at room temperature and heat ten times better than copper.
Because it is only one atom thick, this material is super light 2250Kg/m3 vs 7700kg/m3 steel. It has also demonstrated high biocompatibility, potentially highly renewable since carbon is the fourth most abundant element in the universe and it is almost completely impermeable.
The main way to produce graphene is by a technique called exfoliation. This technique consists in extracting thin layers of graphite by sticking adhesive tape on bulk graphite and peel it off. This process is repeated, obtaining in each interaction graphite slices with fewer layers until only a single-atom-thick mesh of carbon remains.
This technique is used for R&D applications in the lab, but it is not practical for large-scale production. Constantly, new techniques are developed to produce graphene at a greater scale, but still, the purest and of the highest quality graphene is produced by exfoliation.
The two-dimensional structure of the graphene makes possible to create new materials by using graphene as scaffold combining with other compounds. These engineering materials might potentially open even more applications.
Due to its list of properties, graphene has many potential applications, which we will start to see after overcoming all its challenge.
Energy and electronics
Graphene is a promising material for energy storage solutions. Graphene-batteries will be more efficient than the traditional lithium due to no chemical reaction is needed, making them more durable and efficient.
Graphene is also a promising replacement from silicon electronics, its high conductivity together with being thinner and smaller than any other compound makes possible to design smaller and better microprocessors. Especially for CPUs since graphene heat dissipation is 25 times more powerful than silicon.
Because graphene is transparent and flexible, it is a good candidate for flexible screens and optical electronics in general, replacing the current fragile and expensive Indium-Tin-Oxide in touchscreens. These properties can also be exploited to develop more efficient photovoltaic cells (solar panels).
There are also options for ultrafiltration applications. Graphene allows water to pass through it, but is, at the same time, almost completely impermeable to liquids and gases. This second characteristic makes the graphene a good alternative for future pipelines and ultra-sensible gas sensors.
Other areas of research are in the biomedical engineering field to develop wearable sensors of all kinds or even due to its nanoscale to drug development or sequencing DNA.
Finally, as already stated, graphene opens up new possibilities to produce any composite material that has to be strong and light, such as body armours or planes.
History and future
Graphene has been known theoretically for many years. The breakthrough was in 2004 when graphene was isolated for the first time by accident. Research at the University of Manchester sought to isolate pure graphite for its potential as a transistor. They extracted thin layers of graphite by means of exfoliation technique and attached these layers to a silicon substrate with electrodes to create and transistor.
Currently, some graphene-enhanced products have started to appear commercially, but full graphene products are still to come. First applications will probably be related to its electrical conductivity for super-efficient batteries. Applications related to its light and strong mechanical properties will be also expected in the near future. However, bioapplications still have a long way to go before we see them.
In the recent years, graphene has become very popular in the research world and also for the general public, sold as the thinnest, the strongest, the most electrically and thermally conductive, renewable and biocompatible material at the same time. It has been promised as a new revolution as it was plastic. However, there are still many technological challenges to overcome.
Production at large scale
We still do not know how to produce graphene at large scales. Until now the largest sheet of graphene that scientist has been able to produce has been the size of a credit card by exfoliation. Other methods to manufacture graphene are under development, but the quality of the graphene produced is lower.
Basically, the quality of the graphene is based on the number of layers. When graphene is layered, it loses many of its properties, including flexibility and high conductivity. Considering that a graphite crystal of 1 millimetre thick is made of 3 million graphene layers is easy to understand how difficult is to isolate one pure layer of graphene.
However, this balance of purity and scale is similar to the silicon production faced years ago, and due to its fascinating properties, research in the mass-production of graphene is heavily invested.
Superconductor ≠ semiconductor
Another critical point necessary to resolve is that graphene is a superconductor, but it is not a semiconductor. This is important to differentiate since the base of electronics is the ability to change its conductivity to generate zeros and ones. As long as we cannot completely switch off the graphene, this material will not be a serious candidate to overcome silicon.
All bio-applications will probably be the furthest from becoming a reality if they come true at all. Research on the potential toxicity of the graphene is still ongoing, results are contradictory. Although there is room for hope, we can always synthesize new graphite derivatives with better biocompatibility than pure graphene.
Graphene is too good to do not research further. A universe of graphene applications is waiting to be discovered.
Now it is your turn.
- What application do you think will reach first the mass-market?
- Do you think graphene will be as revolutionary as plastic was?
- How long will we wait until seeing objects made of graphene?
Leave us your opinion in the comments.
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- Why graphene hasn’t taken over the world…yet — Youtube video
- State of the art of graphene products — Website
- Review of the quality of the current graphene production — Scientific study
- Review of the biocompatibility and biomedical applications of the graphene — Scientific study
- Graphene: The Superstrong, Superthin, and Superversatile Material That Will Revolutionize the World — Book
- The Graphene Revolution — Book