ONE OF the top materials researchers in the world and Science Foundation Ireland’s Researcher of the Year 2011, Jonathan Coleman, has achieved international recognition for a series of scientific discoveries that could lead to improved plastics, batteries and electronic displays.

The recent European Research Council award of a €1.5 million starter grant to Prof Coleman and his team at the School of Physics, Trinity College Dublin, was recognition for their groundbreaking work on the development of next-generation materials at the Science Foundation Ireland-funded Centre for Research on Adaptive Nanostructures and Nanodevices (Crann).

Coleman’s main research theme is the study of one-dimensional nanostructures such as carbon nanotubes and inorganic nanowires.

His major breakthrough is a new way of splitting layered materials to give atomically thin “nanosheets”, leading to a range of novel two-dimensional nanomaterials with chemical and electronic properties that have the potential to enable new electronic and energy storage technologies as well as new super-strong plastics.

This collaborative international research project was led by Crann and the School of Physics in TCD and the University of Oxford. Coleman and his team invented a versatile method for creating these atomically thin nanosheets from a range of materials using common solvents and ultrasound, utilising devices similar to those used to clean jewellery. The new method is simple, fast and inexpensive, and could be ramped up to work on an industrial scale. The research builds on work on the two-dimensional material graphene, which won the Nobel Prize in 2010.

Graphene has generated significant interest because when separated into individual flakes, it has exceptional electronic and mechanical properties that are very different from those of its parent crystal, graphite. However, graphite is just one of hundreds of known layered materials, some of which may enable powerful new technologies.

“A nanomaterial is defined as a material that has a size in at least one dimension of less than 100nm,” Coleman explains.

“For example, a nanotube made of carbon could be up to 1cm long, but its diameter would be incredibly small. It is a quasi-one-dimensional material. Quasi-two-dimensional materials are nanosheets that have a thickness of one nanometre and therefore might as well be two dimensional, they are so thin. A human hair is 50,000 times as thick as a nanotube, for example.”

Graphene is one of these materials and it is its strength that makes it so interesting and useful. “It is one of the strongest materials known to man,” Coleman points out. “It is 100 times stronger than steel.” He explains that this is important for the development of new composite materials.

“Take a polyester soft-drink bottle for instance. We make these by the hundreds of millions every year. If we were to add half of 1 per cent of a current bottle’s weight in graphene, we would triple its strength. That would enable us to use far less plastic in its manufacture. When you think about how much stuff is made of plastic and how much oil that consumes, you get some idea of the potential importance of a material like graphene in terms of environmental savings.”

And the potential applications as a structural material only start here. “Why do cars have to be made of metal?” Coleman asks.

“Once you start thinking about these things, the possibilities are endless. You can strengthen a material considerably without adding to its weight at all.”

Graphite isn’t the only layered material out there which could enable powerful new technologies, and strength is only one of their useful qualities.

Coleman’s work in Crann will open up more than 150 similarly exotic layered materials – such as boron nitride, molybdenum disulfide, and bismuth telluride – that have the potential to be metallic, semiconducting or insulating, depending on their chemical composition and how their atoms are arranged. This new family of materials opens a whole range of new “super” materials.

These new materials are also suited for use in next-generation batteries or super-capacitors that can deliver energy thousands of times faster than standard batteries, enabling new applications such as electric cars.

“These materials, when fabricated into devices, can generate electricity from waste heat.

“For example, in gas-fired power plants approximately 50 per cent of energy produced is lost as waste heat, while for coal and oil plants the figure can reach is up to 70 per cent.

“However, the development of efficient thermoelectric devices would allow some of this waste heat to be recycled cheaply and easily, something that has been beyond us, up until now,” Coleman explains.

“I would like to see the processes developed which will manufacture the nanosheets in very large quantities and then I would like to see it demonstrated how graphene can be put in a wide range of plastics to increase their strength and reduce the amount of we use.

“If even a fraction of the potential uses comes to pass, we’ll all be using graphene and other nanomaterials in our daily lives in 10 years from now.”