Plastics & Rubber World - November/December 2019 - 13

graphene

"The graphene we make is a natural
product produced from mined graphite
which comes from various places including Africa, China, India and Sri Lanka," says
Ricketts. "We chemically and mechanically explode that natural material into very
thin layers, about 1 millionth the width of
a human hair."
Such distant sourcing could be seen as
a drawback. For example, while lithium is
used to manufacture batteries that drive
electric vehicles and help to reduce overall emissions, CO2 released in moving the
material can erode those benefits. Ricketts says that to reduce the carbon footprint, graphene manufacturing plants are
being sited in close proximity to mining
operations or end users, whichever is the
most environmentally friendly.
"In China, it's better to be closer to the
material manufacturing location," he continues. "The graphite resources are largely
located in Xiangdong and a lot of the manufacturing is in that region. We need to be
aware of the impact of moving materials."

Material aCCess

Like most ores, the graphite must be
broken down to gain the pure material.
"We mechanically and chemically exfoliate sheets away from the bulk materials," says Ricketts. "That produces a slurry which ultimately results in a family of
products. Some of these deliver great
flame retardancy in polymers. At the
other end of the scale there's a very high
quality material used in various technology applications."
Graphite is one of the most readily available materials in the world - billions of pencils can't be wrong. Naturally,
the best graphene comes from the best
graphite, which Ricketts says is mined on
a particular lateral. "If you imagine mining
slate, but on an atomic level, that's essentially what we do."
In delivered form, the graphene nanoplatelets are mixed into a final material, either a plastic or a rubber, respectively resulting in a pelletised or masterbatch-type
product, or a solution. These are then
added to a base polymer in order to gain
the benefits of the graphene product.
Most recently, Versarien has teamed
up with several global partners to develop large-scale commercial production of
high-purity, low-defect graphene nanoplatelets.
"In this particular case, this is a mechanical rather than an electronics grade
of material. So it's for use with plastics,
rubber and concrete. The better the quality of the graphene, the higher the performance," says Ricketts. Continuing, he
adds the quality of the material is defined
by both its purity and thickness. So large,
thin platelets deliver the best overall performance.
To date, he says that access to
high-quality material has held back wider
use of the material. Much of the graphene
in the marketplace has been of a lower

grade and, when added to a base material, those thicker platelets can slide against
each other. This can actually have a negative influence on the mechanical properties of the polymer product.
"This is why we're working with our
partner companies, to ensure we're getting the right quality of material which can
deliver the best performance," says Ricketts. "The challenge of any new product is
to get the performance at a cost that the
customer can build into their pricing."
What Versarien is offering is a comparatively simple, environmentally benign
product which can be used to create material with added benefits. As with most
products, volume will drive improved pricing and allow graphene use to become
more widespread.
"We need to reduce the amount of
plastic we're using and we need higher-strength, lower-cost polymers," Ricketts
puts forward. As a working example, he
tells of one instance where graphene has
been used to increase the working life of a
rubber-based product. Manufactured for
a 'down the hole' application, the part can
remain sub-surface for longer, with fewer
retrievals, which translates to reduced operational costs.
"We can change the performance of
what we would otherwise consider mundane materials," he observes, adding that
lightweighting of parts is another performance benefit of dosing material with
graphene.

Neill ricketts, Ceo of versarien

Plateau of ProduCtivity

As with most new technologies, there has
been a lot of media coverage featuring
graphene and how various business sectors can benefit from the material. The
downside to this is that once the media
hype has faded, the idea drops out of the
public consciousness - all while engineers
are still working in the background to develop new uses.
This is the course graphene has been
navigating since being first introduced,
as demonstrated by the 'Hype Cycle'. In
reaction to the initial launch, the graph
features a steep rise as interest grows.
This then peaks and declines into the
so-called 'Trough of Disillusionment'. But

›› Continued on page 14

Graphene can be delivered in a masterbatch or pelletised form
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