It looked like normal concrete. It poured like normal concrete. But it had a superpower.
James Baker, Managing Director of Graphene@Manchester, couldn’t quite believe what he was seeing as he watched the installation of a new roller disco floor at Manchester’s Mayfield Depot.
The concrete slab hardened so quickly and so hard that builders had begun sliding polishing machines over the driest part of the floor while their colleagues were still pouring the other end of the rink.
“Usually you’d have to wait a week before you could do that,” he says. Installation last October took less than a day.
This concrete was special because it contained a tiny but transformative amount of graphene, microscopic flakes of carbon atoms arranged in a honeycomb lattice.
Graphene is the strongest material ever discovered, but has struggled to find a revolutionary role in commercial products for nearly two decades. Will that change soon?
In addition to improving the mechanical properties of certain materials, it is hoped that graphene could also make some projects more environmentally friendly.
“By adding just 0.1% graphene to cement and aggregate, you can potentially use less material to achieve the same performance,” explains Mr. Baker. For example, a 30% reduction in the amount of concrete used in construction could reduce global CO2 emissions by 2-3%, he estimates.
As well as the scooter disco, Mr Baker and his colleagues have also been testing graphene-enhanced concrete, known as Concretene, at a gym in Wiltshire and on a number of road projects, including a several hundred meter stretch of the A1 in Northumberland.
The team will also be pouring concrete at a yet-to-be-announced project in the United Arab Emirates this year.
Those early attempts involved fairly straightforward projects, Mr Baker explains – floor slabs rather than walls or raised platforms, which could be more risky. So far, however, the Concretene has performed as expected.
But why does graphene have this effect on concrete? Carbon fiber has been used to reinforce concrete before, and graphene (although flakes of it are much smaller than carbon fibre) plays a similar role, says Lisa Scullion of the University of Manchester’s Graphene Engineering Innovation Centre.
However, there is more happening. The fragments of graphene can also change how the concrete sets around them.
“It provides almost nucleation sites on the surface of the graphene to regulate this structure within the concrete,” says Dr. Scullion, adding that scientists are still working on the consequences of this. It could make the concrete more dense or change the pore structure in the concrete.
Maybe a little closer to a block of cheddar, as opposed to Swiss cheese, I suggest.
For some applications, it is enough to eliminate the need for reinforcing bars in the concrete, says Dr. scullion
Beyond concrete, graphene could also improve the durability of paint and coatings and ward off rust. “Because you have all these tiny flakes, water and corrosive ions can’t penetrate to the metal as quickly,” says Dr. scullion
And by improving the strength of building materials, architects could one day design much more elaborate and irregular facades, some of which may be inspired by shapes in nature, suggests Pasquale Cavaliere of the University of Salento.
Graphene has caused a stir for years since its discovery at the University of Manchester in 2004. The hype surrounding it has itself become the subject of studies, and some remain skeptical that it will live up to those high expectations.
The excitement surrounding graphene has created a “wild west” situation in which some products containing the material may be highly priced but are actually of low quality, said Krister Svensson, associate professor of physics at Karlstad University, in a 2019 published interview.
He told BBC News that the quality of graphs used today varies widely. He also questions whether using graphene as a reinforcing agent is really necessary, since graphite and carbon fibers can play a similar role.
“Graphene is still relatively young,” admits Mr. Baker. But he and his colleagues are determined to “accelerate the adoption of graphs,” he adds.
More technology of business:
Companies that have experimented with the material have sometimes found it to have slightly different uses than originally intended.
“We love graphene,” says Debbie Mielewski, Ford’s sustainability technical fellow. She says the automaker has shipped between six and seven million vehicles since 2018, mostly in North America, that contain graphene in a handful of parts.
She and her team were initially interested in graphene for its strength-enhancing properties. However, they found that it was actually more useful in terms of reducing noise and vibration or improving heat resistance.
Cars, including the F-150 and Explorer SUVs, now include 12 small components in and around the engine, like pump covers or water pipe brackets, that are equipped with graphene, in part because it absorbs noise.
Depending on the frequency of the sound, these components can reduce the noise heard in the vehicle by 12 to 25%, says Dr. Mielewski.
It also lightened those parts, reducing the car’s overall mass by about a pound and a half (680 g). This means that these vehicles use slightly less fuel and therefore have lower CO2 emissions over their lifetime.
Ford is working with US companies XG Sciences and Eagle Industries on various graphene applications.
according to dr Mielewski, the automaker is exploring the possibility of adding graphene to automotive interior plastics to make them stronger, but says they haven’t been able to disperse graphene in the plastic as well as hoped.
This is often a major stumbling block when adding graphene to a given material. In order to actually improve its properties, the graphene needs to be evenly dispersed. But depending on how the material is shaped or mixed, and the temperatures and pressures involved in the process, it can be difficult to get the desired result.
It’s a bit more complicated than that, but imagine trying to get an even distribution of raisins in a fruitcake when the batter is too runny.
A wonderfully even mix and a material that is clearly enhanced by the addition of graphene is the goal of all these researchers and companies.
Because with graphs, the proof is definitely in the pudding.