Dr Michelle Dickinson, also known as Nanogirl, is an Auckland University nanotechnologist who is passionate about getting Kiwis hooked on science.

Nanogirl Michelle Dickinson: Flexible use for waste oil

An easy way to coat surfaces with wonder material graphene may soon put foldable phones in our pockets.
Graphene is thin, light, strong and a super conductor. 
Picture / 123RF
Graphene is thin, light, strong and a super conductor. Picture / 123RF

Imagine if your smartphone battery could charge in five seconds, last for weeks on a single charge, and its screen didn't smash when you dropped it.

Graphene supercapacitors and graphene coated screens produced using new, lower cost techniques could soon deliver these advances.

Graphene is the thinnest and one of the lightest materials known to man. At one atom thick, one square metre weighs only 0.77mg.

Its unique structure is made purely of carbon atoms bonded together in a single-layered hexagonal honeycomb lattice which gives it remarkable electrical properties and amazing strength for its weight.

It is this honeycomb structure that makes graphene different to other pure carbon structures such as diamonds, which have their carbon atoms in a pyramid-shaped structure, and fullerenes such as the cylindrical carbon nanotubes.

Graphene has been proven to be much more efficient at conducting electrons than silicon, used at present in most computer chips. With graphene's other remarkable properties, electronics such as smartphones, touchscreens and even solar panels could be flexible and even foldable in the future.

To date, the high production costs associated with graphene's manufacture have been prohibitive to its widespread use - but this could be about to change.

Thirteen years ago, when graphene was isolated and characterised by Andre Geim and Konstantin Novoselov at the University of Manchester, it was paraded as a wonder material with potential applications in the paints, electronics, medicine and filtration industries.

Sadly though, although it's been a hot topic of research in the scientific field ever since, the large scale commercial applications of graphene are limited by the difficulty in mass producing it at a low enough cost.

There are several ways that graphene is produced. The original discovery, which earned Andre and Konstantin, a Nobel Prize was to peel layers away from graphite simply using sticky tape.

However, for technology applications, graphene is used as a film on a metal or ceramic surface which requires energy intensive and expensive coating techniques.

The most common coating method is called chemical vapour deposition, where a carbon-based gas such as methane is pumped into a closed container containing the surface to be coated. The container is then held at high temperatures and pressures until the whole surface has had graphene deposited on it.

Scientists in Australia this week published exciting research in the journal Nature Communications describing their cheap and easy method of producing graphene on nickel surfaces using soybean oil at room temperature.

Instead of using expensive high purity gas, their method heats soybean oil in a quartz tube furnace for 30 minutes.

This heat causes the oil to break down into smaller building blocks, which further dissociate into carbon atoms and dissolve into the nickel substrate. The tube is then quickly cooled so that the carbon atoms segregate from the nickel and crystallise on the metal surface forming a permanent layer of graphene on the top.

The process has so far been proven by coating graphene on nickel, but has the potential to significantly reduce the cost of producing films on other surfaces as well.

The potential to use cheap vegetable oils and biofuels in this simple, fast and safe heat treatment process creates the possibility of recycling waste oils into something truly world changing. It can also dramatically reduce the costs of graphene production, and so make the integration of graphene in consumer products more likely.

With this study and others providing new, cheaper and more efficient ways of producing graphene, the quest to find a new way to bring this incredible material out of the lab and into our lives is another step closer.

- NZ Herald

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Dr Michelle Dickinson, also known as Nanogirl, is an Auckland University nanotechnologist who is passionate about getting Kiwis hooked on science.

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