“The National Physical Laboratory (NPL), in collaboration with international partners, have developed an ISO/IEC standard, ISO/TS 21356-1:2021, for measuring the structural properties of graphene, typically sold as powders or in a liquid dispersion. The ISO/IEC standard allows the supply chain to answer the question ‘what is my material?’ and is based on methods developed with The University of Manchester in the NPL Good Practice Guide 145.
Over the last few years, graphene, a 2D material with many exciting properties and just one atom thick, has moved from the laboratory into real-world products such as cars and smartphones. However, there is still a barrier affecting the rate of its commercialisation, namely, understanding the true properties of the material. There is not just one type of material, but many, each with different properties that need matching to the many different applications where graphene can provide an improvement.
With hundreds of companies across the globe selling different materials labelled as ‘graphene’, and manufacturing it in different ways, end users who want to improve their products by incorporating few-layer graphene flakes are unable to compare and subsequently select the right material for their product.
Through standardised methods to enable the reliable and repeatable measurement of properties, such as the lateral flake size, flake thickness, level of disorder and specific surface area, industry will be able to compare the many materials available and instil trust in the supply chain. In conjunction with the international ISO/IEC terminology standard led by NPL, ISO/TS 80004-13:2017, it will be possible for commercially available material to be correctly measured and labelled as graphene, few-layer graphene or graphite.
As the UK’s National Metrology Institute, NPL has been developing and standardising the required metrologically-robust methods for the measurement of graphene and related 2D materials to enable industry to use these materials and realise novel and improved products across many application areas.
The continuation of the NPL-led standardisation work within ISO TC229 (nanotechnologies) will allow the chemical properties of graphene related 2D materials to be determined, as well as the structural properties for different forms of graphene material, such as CVD-grown graphene.”