Irish researchers have found a new use for Irish whiskey – creating the world’s wonder material, graphene.

The discovery was made by researchers at the SFI Research Centre for Advanced Materials and BioEngineering Research (Amber), hosted by Trinity College Dublin, when they were investigating new ways to make the material.

Graphene is one of the thinnest and strongest materials in the world, and is known to have unique mechanical and electrical properties. It is the world’s first 2D material, almost completely transparent. And at an atom thick, it is the thinnest material known to science. Its conduction properties open up potential uses in computers, smartphones and sensors.

One of the most efficient ways of making it is through a process called liquid-phase exfoliation (LPE), which was pioneered by Amber researchers and produces nanosheets from layered crystals.

Defect-free sheets

The new research found Irish whiskey could be used to produce defect-free sheets of graphene. The project also found that printable inks produced using the whiskey LPE process could be printed into nanosheet networks for future use in electronics such as RFID tags, data storage or pixels in OLED televisions.

The team looked at a number of alcoholic liquids for the process, and found Irish whiskey – in this case, Teeling Small Batch Irish Whiskey – produced the best results.

“Whiskey is uniquely suited for stabilising our nanomaterials because of the maturation process it must undergo,” explained Prof Jonathan Coleman, Amber co-lead investigator on the project and principal investigator in Amber and Trinity’s school of physics.

“Before a spirit can be called a whiskey, it needs to be aged in a barrel for a minimum of three years and, over the three years, the majority of the flavour compounds are added to the whiskey. Other clear spirits like vodka are ostensibly just water and ethanol – flavourings are added according to the brand – so they lack the broad compound profile inherent to whiskey. These compounds are what help to stabilise our nanomaterials.”

Stability

The whiskey process showed better results for stabilising nanomaterials in a liquid or ink compared with the current process of mixing water and ethanol.

“We have shown that 2D nanomaterials are more stable in whiskey than simply water and ethanol and that the whiskey with the suspended nanomaterials can be printed using aerosol jet printers,” said Dr Adam Kelly, a post-doctoral researcher at Amber.

“We have now created whiskey-based inks of graphene and tungsten disulphide [a conductor and semiconductor] so we are able to print working transistors. While there is scope to improve their performance, the fact that they function at all shows that devices made from 2D nanosheets can withstand contamination to a high degree.”