The Concorde was the first commercial supersonic aircraft to have been built. Image: Wikimedia Commons

In 2011, a chance encounter under the wings of Concorde at Duxford Air Museum, Cambridge, with Trinity College Dublin Professor Johnny Coleman, would set in motion a series of events that would lead, six years later, to the development of a 20t/year graphene manufacturing plant.

As soon as we got talking, I was impressed by Johnny’s practical, non-nonsense approach to solving the scalability issue with graphene production.

Coleman is a physicist, not a chemist, and believed that the solution lay in mechanical techniques. Following the conference, Thomas Swan agreed to fund his group for four years to develop a scalable process for the manufacture of graphene.

 

Just a nanometer thick, graphene consists of a single layer of carbon atoms joined in a hexagonal lattice. Image: Pixabay

Coleman and his team initially considered sonication – when sound waves are applied to a sample to agitate its particles – but quickly ruled it out due to its lack of scalability. He then sent one of his researchers out to the shops to buy a kitchen blender. They threw together some graphite, water, and a squirt of washing-up liquid into the blender, switched it on, and went for a cup of coffee.

When they later analysed the ‘grey soup’ they had created, they found they had successfully made few-layer graphene platelets. The group then spent months optimising the technique and worked closely with Thomas Swan scientists to transfer the process back to Thomas Swan’s manufacturing HQ in Consett, Ireland.

Graphene is 300 times stronger than steel.

The plant can make up to 20t/year of high quality graphene. It uses a high sheer continuous process to exfoliate graphite flakes into few-layer graphene platelets in an aqueous dispersion.

The dispersion is stabilised by adding various surfactants before separating out the graphene using continuous cross-flow filtration devices developed with the support of the UK’s Centre for Process Innovation (CPI), part of the High Value Manufacturing Catapult – a government initiative focused on fostering innovation and economic growth in specific research areas.

 

Using sticky tape, scientists pulled off graphene sheets from a block of graphite. Image: Pixabay

This de-risking of process development using a Catapult is a classic example of effective government intervention to support innovative SMEs. CPI not only showed us it worked, but also optimised the technique for us.

The company quickly realised that selling graphene in a powder form with no application data was not going to work. Instead, we developed a range of performance data to assist the sales team by highlighting what graphene can do if adopted into a range of applications.

The potential of graphene can be commercialised using composites. Video: The University of Manchester – The home of graphene

We also moved to make the product available in ‘industry friendly’ forms such as epoxy resin dispersions or polymer masterbatches. This move, slightly downstream from the raw material, has recently led to Thomas Swan announcing its intention to expand its range of formulated graphene materials, with a prototype product focusing on the manufacture of a carbon fibre composite.

Our application data shows that graphene has significant benefits as an industrial additive. Presenting this data to composite-using downstream customers is starting to open doors and create supply chain partnerships to get a raw material all the way to a fully integrated application.

 

Andre Geim and Kostya Novoselov won the 2010 Nobel Prize in Physics for their discovery of graphene. Image: Wikimedia Commons

The move downstream, to develop useable forms of graphene, is common in the industry, with most graphene suppliers now making their products available as an ink, dispersion or masterbatch. Thomas Swan’s experience with single-wall carbon nanotubes has made us aware of the need to take more control of graphene application development to ensure rapid market adoption.

Graphene applications drawing most interest include composites, conductive inks, battery materials, and resistive heating panels, although much of this demand is to satisfy commercial R&D rather than full commercial production.

Graphene science | Mikael Fogelström | TEDxGöteborg. Video: TEDx Talks

Thanks to innovations like our continuous high sheer manufacturing process, Thomas Swan believes that graphene is about to become very easy to make. Before it can be considered a commodity, however, it will also need to deliver real value in downstream applications. Therefore, the company is also increasing its efforts to understand market driven demand and application development.

As the initial hype over the ‘wonder’ material graphene starts to wane, progress is being made to develop scalable manufacturing techniques and to ensure graphene delivers some much-promised benefits to downstream applications.