| Date | 12th, Dec 2019 |
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Graphene – widely known for its exceptional strength – has just become even tougher! Researchers from South Korea have recently found a way to transform this fascinating, one-atom-thick material into ultrathin sheets as tough as nails made from diamond.
The process of linking the carbon atoms of graphene in a three-dimensional manner to make a 2D form of diamond known as diamane requires either extremely high pressures, which means that once the pressure is removed the effect is lost, or the addition of hydrogen atoms, which makes it difficult to control the bonds.
When it comes to diamonds, the process is no easier to replicate as diamonds are formed at high temperatures and pressures found deep inside the Earth. If graphene is to be taken up a notch in terms of strength, a different approach is necessary.
Interlayer bonding between the separate layers of graphene, accomplished by exposing the material to fluorine, leads to ultrathin layers of diamond. Image: pxfuel.com, CC0
In a study published in the journal Nature Nanotechnology, researchers from the Institute for Basic Science (IBS) and the Ulsan National Institute of Science and Technology (UNIST) describe a new technique whereby stronger bonds between carbon atoms are achieved by exposing bilayer graphene to fluorine, instead of hydrogen.
The conversion was accomplished by deploying the tried-and-true method of chemical vapour deposition (CVD) on a substrate made of copper and nickel. Once exposed to xenon difluoride, the material became significantly stronger – the fluorine contained in the mix stuck to the carbon atoms, strengthening the bonds between them and resulting in a fluorinated diamond monolayer called F-diamane.
“This simple fluorination method works at near-room temperature and under low pressure without the use of plasma or any gas activation mechanisms, hence reduces the possibility of creating defects,” said first author on the study Pavel V. Bakharev.
Given the relative simplicity of the process, it can be scaled up with relative ease and find many applications in nano-optics, nano-electronics, as well as provide a platform for micro- and nano-electromechanical systems.
Sources: study abstract, ibs.re.kr, newatlas.com
