Since the first separation of graphene in 2004, graphene research and development has exploded with numerous business opportunists producing graphene to invest in this rapidly expanding industry. However, a new study by a researcher at the National University of Singapore (NUS) has identified a major problem. Due to the lack of production standards, many of the graphenes were of poor quality from the suppliers. This practice can hamper the progress of research that is fundamentally dependent on the use of high quality graphene.
"It's surprising that the producers are showing black powder as graphene and selling it in the top dollar, and it actually contains cheap graphite." There is a need to maintain good health by establishing strict criteria for the characterization and production of graphene. "Said Antonio Castro Neto, professor at the NUS Center for Advanced 2D Materials, who led the study.
The results were published in the journal. Advanced Materials September 13, 2018
How to tell graphene flakes from graphene fakes
Graphene is a miracle material of the future because of its outstanding characteristics. Even though it is the thinnest material on earth, it is 200 times stronger than steel. With only one atomic thickness, it is also an unbelievable electrical conductor, but light, flexible and transparent. Therefore, graphene is looking for potential applications in all areas, from transistors to biomedical devices, and even proposed as a material for building elevators in space.
Graphene is produced by separating graphite, which can usually be found in common pencil leads, into powder, immersing the powder in liquid, and using acoustic energy to vibrate the mixture to separate the smallest graphene pieces. The goal of this synthesis is to produce the thinnest possible graphene. While pure graphene is only one atomic layer thick, the International Organization for Standardization (ISO) says graphene flake stacks up to 10 stories thick can still behave like graphene.
With this in mind, Professor Castro Neto and his team have begun to develop systematic and reliable methods to establish the quality of graphite samples from around the world. They were able to achieve this using a wide range of analytical techniques and were able to test samples from many suppliers.
Analyzing samples from more than 60 different suppliers in the Americas, Asia and Europe, the NUS team found that they contained less than 10% of what could be considered graphene chips. Most of the samples were graphite powders that were not adequately peeled off.
It is unclear whether graphene makers are aware of poor quality, but lack of graphene production standards can lead to poor quality materials sold in the open market, delaying the development of future applications. "Professor Castro Neto elaborated.
Because graphite powder and graphene have very different properties, all studies carried out under the pretext that the sample is pure graphene produce inaccurate results. In addition, only one of the samples tested in this study contained over 40% of high-quality graphene. Some samples were also contaminated with other chemicals used in the production process. These results mean that researchers can waste valuable time and money in conducting experiments on products that are advertised as false.
It is important that research is not hampered in this way, given the important challenges associated with health, climate and sustainability that graphenes can solve as the first study to statistically analyze the global production of graphene scraps. "Castro Neto) explained.
Overcome the barriers of graphene innovation
With this discovery and the development of reliable test procedures, we can keep the graphene samples at a higher standard.
"We hope to accelerate the process of graphene standardization within ISO as a result of the need for a huge market," he says. "Grape producers around the world produce products with better characteristics that can help them develop. I will urge you to improve the method, the actual application, "Professor Castro Neto said.
In addition, testing graphene using universal, standardized methods makes it easy to compare data produced by users and labs around the world.