After a slow start, composites manufacturers are taking advantage of graphene’s unique properties.
In 2004, working at the University of Manchester in the United Kingdom, researchers Andre Geim and Kostya Novoselov produced graphene, the world’s first two-dimensional, man-made material. In the following years, graphene was hailed as a wonder material because of its many remarkable properties. Despite being extremely lightweight and a million times thinner than a human hair, graphene is the world’s strongest material, with 200 times the tensile strength of steel. It has high electrical conductivity and thermal conductivity, is practically transparent, is impermeable and extremely flexible and stretchable. What makes graphene truly unique, however, is its ability to provide all these properties at once.
“With most materials, if you want to get one beneficial property you have to introduce some negative aspects, but with graphene you can impart multiple properties simultaneously and without the typical tradeoffs in many, many cases,” says Terrance Barkan, executive director of The Graphene Council.
Like many other high-tech discoveries, graphene didn’t initially live up to the hype. Early attempts to capitalize on its properties were unsuccessful, and many companies became dubious about its ability to deliver what was promised. There were several reasons for these failures.
“In many cases, the companies that thought they were working with graphene were actually working with material that may have had carbon in it, but wasn’t really graphene,” says Barkan. Manufacturers also found it very difficult to disperse graphene throughout a matrix to get the desired properties.
Early adopters were also confused by graphene’s unusual behavior. Composite material manufacturers, for example, are accustomed to adding more of a substance to a composite when they want to increase the properties it imparts to a material. But graphene has the reverse effect; reducing the quantity used generally improves the graphene-enhanced composites’ performance. Companies that initially added 1% graphene by weight to their composite materials achieved better results when they decreased the amount to 0.5% by weight.
“The magic of this material is that an incredibly small amount of it can dramatically improve the performance of other materials,” Barkan says.
With continued research and experimentation, companies have gained a better understanding of graphene’s behavior and are finally realizing its benefits. The nanomaterial is proving to be a valuable asset for the composites industry since it can be used for thermoset and thermoplastic composites, incorporated into glass, carbon and basalt fibers, and used with a variety of resins.