Saturday 15 October 2011

Bakelite II, the revenge

More on The wonder stuff that could change the world: Graphene

So strong a sheet of it as thin as Clingfilm could support an elephant

Graphene (as we call it Bakelite II) is formed of honeycomb pattern of carbon atoms, could be the most important new material for a century

It is tougher than diamond, but stretches like rubber. It is virtually invisible, conducts electricity and heat better than any copper wire, and weighs next to nothing.

Meet graphene — an astonishing new material which could revolutionise almost every part of our lives.
Some researchers claim it’s the most important substance to be created since the first synthetic plastic more than 100 years ago.

If it lives up to its promise, it could lead to mobile phones that you roll up and put behind your ear, high definition televisions as thin as wallpaper, and bendy electronic newspapers that readers could fold away into a tiny square.

It could transform medicine, and replace silicon as the raw material used to make computer chips.

The ‘miracle material’ was discovered in Britain just seven years ago, and the buzz around it is extraordinary.

Last year, it won two Manchester University scientists the Nobel Prize for physics, and this week Chancellor George Osborne pledged £50million towards developing technologies based on the super-strong substance.

In terms of its economics, one of the most exciting parts of the graphene story is its cost. Normally when scientists develop a new wonder material, the price is eye-wateringly high.

However, graphene is made by chemically processing graphite — the cheap material in the ‘lead’ of pencils. Every few month’s researchers come up with new, cheaper ways of mass-producing graphene, so that some experts believe it could eventually cost less than £4 per pound.

You would need to stack three million graphene sheets on top of each other to get a pile one millimetre high. It is also the strongest substance known to humanity — 200 times stronger than steel and several times tougher than diamond.

A sheet of graphene as thin as Clingfilm could hold the weight of an elephant. In fact, according to one calculation, an elephant would need to balance precariously on the end of a pencil to break through that same sheet.

Despite its strength, it is extremely flexible and can be stretched by 20 per cent without any damage.

It is also a superb conductor of electricity — far better than copper, traditionally used for wiring — and is the best conductor of heat on the planet.

However, perhaps the most remarkable feature of graphene is where it comes from. Graphene is made from graphite, a plentiful grey mineral mostly mined in Chile, India, and Canada.

A pencil lead is made up of many millions of layers of graphene. These layers are held together only weakly — which is why they slide off each other when a pencil is moved across the page.

Graphene was first isolated by Professors Konstantin Novoselov and Andrew Geim at Manchester University in 2004. The pair used sticky tape to strip away thin flakes of graphite, and then attached it to a silicon plate, which allowed the researchers to identify the tiny layers through a microscope.

Its discovery has triggered a boom for material science. Last year, there were 3,000 research papers on its properties, and 400 patent applications.

The electronics industry is convinced graphene will lead to gadgets that make the iPhone and Kindle seem like toys from the age of steam trains.

Modern touch-sensitive screens use indium tin oxide — a substance that is transparent but which carries electrical currents. However, indium tin oxide is expensive, and gadgets made from it shatter or crack easily when dropped. Replacing indium tin oxide with graphene-based compounds could allow for flexible, paper-thin computer and television screens. South Korean researchers have created a 25in flexible touch-screen using graphene.

Ancient history: If the development of graphene is successful it will make the iPad and Kindle seem like toys from the age of the steam train

It is also being touted as an alternative to the carbon-fibre bodywork of boats and bikes. Graphene in tyres could make them stronger.

Some even claim it will replace the silicon in computer chips. In the future, a graphene credit card could store, as much information as today’s computers.

Dr Sue Mossman, curator of materials at the Science Museum in London, says graphene has parallels with Bakelite — the first manufactured plastic, invented in 1907.
Resistant to heat and chemicals, and an excellent electrical insulator, Bakelite easily made electric plugs, radios, cameras, and telephones.

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