20 Things you need to know about Graphene
I’m really interested in the future. As a scientist by background I like making sense of innovative and creative developments, clarity from complexity is what I strive to achieve.
Graphene is one of the strands of continuing interest for me because it combines science, technology and future orientation. The pieces of the graphene puzzle have not fallen into place yet. It is an amazing material, during the past 10 years much of its capabilities have been understood.
Looking at the hype surrounding graphene you’d be forgiven for thinking that all it needs now is some money invested and everyone will make millions – maybe. There is still more science to do and also far more technology and commercialisation than most realise, not least simply making the stuff has more challenges than people expected.
I’ve put together 20 things about graphene that might interest you; some you’ll be aware of and some might be new to you…
- You can make graphene, yes really – try this: Take an ordinary graphite pencil and draw a line on a piece of paper. Gradually reduce the pressure to make the line fainter and fainter until the pencil point leaves the paper. Somewhere along the very faintest part of that line you have drawn will be the wonder product of the moment – graphene.This experiment tells you a lot of what you need to know about graphene. It can be made from graphite, but having got some it is rather hard to do something useful with it – at the moment.
- Graphene is the thinnest material in the world, it is one atom thick, hence the term 2D material.
- This 1 atom thick layer absorbs 2% of light while this doesn’t sound much it is surprisingly quite a lot. This means you can actually see the 1 atom thick layer faintly shimmering with the naked eye. As a suspension in a liquid it looks black.
- It is 200 times stronger than steel yet far more flexible…
- It is a superb conductor of heat and electricity; it has lots of useful properties combined in one material.
- It is super-hydrophobic, it repels water so it could be used as a coating to make ships go faster, or improve the efficiency of heat exchangers.
- Graphene can be chemically modified to create graphene oxide. This material does not conduct electricity as well as graphene but becomes water loving rather than water repelling. This means it has promise in creating membranes for water purification in the future.
- To realise its full potential graphene needs to be produced in large scale. Large scale means different things to different people: To some it means producing graphene in kilogram quantities – but very small (nanometre sized) flake particles of graphene.To others it means producing larger (millimetre sized) flake particles but in microgram quantities. There is much potential for confusion when describing graphene production.
- Graphene can be made from graphite using scotch tape where very small quantities of high quality large flakes by peeling layers from a graphite crystal – currently the best method for producing high quality flakes for research laboratories.
- Graphene can be made from graphite by liquid exfoliation – where either chemical or mechanical treatments separate the graphene layers. This produces kg scale quantities of nanometre scale graphene usually in suspension as a paste in water based or solvent based liquid.
- Graphene can be made from methane gas – A method called chemical vapour deposition (CVD) on copper. This creates graphene at millimetre sizes. The quality of the graphene is variable caused by defects on the surface of the copper.A team at Oxford University has just developed a new CVD method that grows the graphene on a liquid layer. This holds the potential to create defect free graphene faster than the copper method.
- No method currently exists to make continuous defect free graphene sheets larger than 10 centimetres. Most experts believe that the CVD method will be the most promising graphene production method for the future, rather than exfoliation from graphite.
- Graphene can be confused with other carbon materials such as carbon nanotubes. These are tubes of rolled up graphene that are quite different to sheet graphene. These are sometimes called one-dimensional (1D) materials.
- Europe has invested €1billion in a graphene flagship programme to support R&D and commercialisation of graphene. Companies and Universities around the world have immense resources focussed on graphene applications as evidenced by the numbers of patents – over 24,000 worldwide in the last 10 years, 9,000 of those being in 2014 alone.
- Health and safety – Graphene seems to be relatively safe. The European graphene flagship programme has found no hints of toxicity so far. The Nobel prizewinning co-discoverer of graphene, Sir Konstantin Novoselov, pointed out that all of the original researchers working with graphene over the last 10 years still appear to be quite well and healthy.
- Graphene will not replace silicon semiconductors in computing for a long time to come. Graphene does not have the band gap that is needed to make transistors function properly.
- Graphene can be 3D printed, just not very well at the moment – Graphene inks are in development, the difficult problem to be overcome is getting the 3D printed layers to stick together. Current research is looking at UV curable resins to add into the ink that do not interfere with the properties of graphene.
- Small amounts of graphene go a long way. For example there are 2 billion smartphones made each year. If graphene could be used to make the touchscreens this entire market demand could be satisfied with just 60kg of graphene.
- We are all still waiting for the killer application of graphene – something that graphene does better than any other material and solves a problem for consumers that leads to a huge market demand.
- Long term development – Graphene was discovered in 2004, yet is still in its development phase. Investors need to be aware that it could take another 10 to 20 years before full-scale commercialisation of graphene takes place.
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Adrian Nixon is a Senior Editor at InvestorIntel. He began his career as a scientist and is a Chartered Chemist and Member of the Royal ... <Read more about Adrian Nixon>