Researchers at SFI Research in Advanced Materials and Bioengineering (AMBER, Dublin, Ireland) and Trinity’s School of Physics (Dublin), alongside colleagues from Cambridge Graphene Center (UK), University of Cambridge, University of Newcastle and University of Stavanger (Norway) announced the development of a next generation, scalable low-cost production method for graphene in the Nature Journal 2D Materials and Applications. Research suggests the process could significantly reduce graphene production costs to ~£20 (~$27) per liter when scaled up, and produce multi-ton quantities if successfully commercialized, surpassing by far the current global supply of graphene (~one kiloton). This could potentially help accelerate industry adoption of graphene and encourage graphene manufacturers who were previously hampered by high equipment and labor costs.
Graphene and other atomically thin “2D materials” are expected to find major commercial applications in the coming years due to distinctive electrical, optical, mechanical, chemical and thermal properties. Graphene can be used as a barrier material for anti-corrosion, as an additive for mechanical reinforcement in polymers or as a conductive material in sensors. According to the researchers, these applications will require high-quality, flawless graphene supplied in quantities exceeding current supplies at lower cost.
The research team’s approach is based on the graphite exfoliation process – a bulk method for producing graphene from graphite. They found a new semi-automated, low-turbulence process using computational fluid dynamics engineering to exfoliate graphene flakes from graphite with minimal defects. The method not only produces high-quality graphene “flakes” suitable for industrial commercialization – and ideal for applications requiring high conductivity – but is an inexpensive, in-line, closed process that also recycles unused graphite, ensuring a high efficiency.
Diagram of the new online process. Graphite, deionized water and SDC stabilizer are added to the tank. The shear rotor head pushes the material around the system while generating shear force, allowing the exfoliation of graphite into graphene.
Building on this approach, the team created high-quality graphene inks and used home inkjet printers to fabricate conductive interconnects and lithium-ion battery anode composites that could potentially connect a battery to a textile sensor that could then be used to measure vital signs. in the wearable health industry, among other applications. Considering applications in wearable electronics, textile electronics, composites and printed interconnects that could involve human contact with high concentrations of graphene, the team worked with colleagues at the University of Stavanger to determine the biocompatibility of graphene inks. Repeated measurements showed no acute toxicity when using the highest concentration of graphene in 48 hour cell culture treatments.
“We have demonstrated energy storage composites and printed electronic components in our work, however, there are many other applications that could be achieved with graphene inks, such as [fiber]-reinforced composites or printed sensors,” says lead research author Dr. Tian Carey, who suggests this is just the beginning. “Furthermore, graphene is just one example of a conductive 2D material; there are hundreds of other lesser known 2D materials that have different but complementary electronic behavior that we can apply this process to and create a suite of inks with different but complementary properties.
“About ten years ago, I pioneered a simple method of making graphene from graphite by exfoliation in a home kitchen blender that has since been scaled up and commercialized,” adds the Professor Jonathon Coleman, commenting on the success of his team and collaborators. “In this work, we further adapted the method for industrial application and showed that we can produce high-quality, low-cost graphene in a very efficient and easily scalable way.”
The study was funded by Science Foundation Ireland, a Marie Skłodowska-Curie Action Individual “MOVE” grant, and supported by the Engineering and Physical Sciences Research Council (EPSRC), UK.
Read it full research article here.