What exactly is graphene?
At the Centre for Advanced 2D Materials (previously, Graphene Research Centre) we have been working on basic science and the technology of graphene and other 2D Materials. One of our goals is to deliver an industrial definition of graphene that can be used worldwide and will help to guide graphene produces, developers, and researchers.If you have not heard about graphene it is either because you are not connected to the internet or you live in another planet. Graphene was isolated in 2004 by Geim and Novoselov using a scotch-tape method to exfoliate graphite. In 2010, the Nobel Prize in Physics was awarded to duo in recognition for the amazing feat.Graphene has been called as the new Wonder Material by many, and more than 5 billion US dollars have been invested worldwide in research related to this material in the last few years.
The strict scientific definition of GRAPHENE is that of a pure-carbon mono-layer material, one atom thick (0.34 nm in thickness), with a planar sp²-bonded carbon structure that are densely packed in a honeycomb-shaped crystal, as shown in the figure above on the left. Graphite, on the other hand, is an enormously large number stacked graphene layers forming a three dimensional (3D) structure, as shown in the figure above on the right.
Over the last 12 years, a wide range of definitions have emerged for graphene-based materials due to the large number of production processes that have been developed. The definitions used by the graphene suppliers for different graphene-based materials may vary from a single-layer of carbon atoms to even hundreds of layers in a stack, which is essentially thin graphite.
Much of the noise about Graphene has arouse from the fact that this material has amazing properties including ultimate tensile strength of 130 GPa (hundreds of times stronger than steel), very high electron mobility even at room temperature, thermal conductivity higher than 2,000 W m−1 K−1, and optical transparency around 98% (yes it is transparent). Usually, the higher the number of graphene layers the less outstanding the properties are. However, multi-layered graphene (below 10 layers) still have very interesting properties from the application point of view.
The major current applications of graphene range from composites, coatings, separation membranes, and batteries to high-end products such as touchscreen displays and transistors. But who knows what the future can bring?
Furthermore, graphene is a nanomaterial by ISO definition because it has at least one dimension smaller than 100 nm. New ISO standards have currently been drafted for further clarity on this definition, but also to help the market to have a better understanding on what is real graphene or simply thin graphite (95% of the global suppliers sell thin graphite only!).
Until now, the graphene supply market is still very blur and misleading, which is preventing the application companies to bet on the graphene R&D for future products.
At the Centre for Advanced 2D Materials (previously, Graphene Research Centre) we have been working on basic science and the technology of graphene and other 2D Materials. One of our goals is to deliver an industrial definition of graphene that can be used worldwide and will help to guide graphene produces, developers, and researchers. Furthermore, at CA2DM we are also producing extreme high quality graphene that can be used in graphene applications, not graphite ones. Graphite is not graphene, and these two materials have very different properties and applications.
In the next posts we will show what is the situation of graphene production worldwide and the work done at CA2DM in order to make graphene into a world revolutionizing material.