Researchers at Amber produce graphene using Irish whiskey
24 October 2019 | 0
SFI researchers have found an unlikely use for whiskey; to produce high-quality graphene.
Researchers from Amber, the SFI centre for Advanced Materials and BioEngineering Research, have discovered a way to exfoliate graphene using Irish whiskey.
Graphene is a single layer of graphite. It is flexible, transparent, highly conductive and seems highly impermeable to most gases and liquids. While it is a mere one-atom thick, it is one of the strongest known materials. This unique combination of properties could make it a real game-changer in the future of portable electronics.
In the study, published in the journal 2D Materials, the team outline that defect-free nanosheets can be exfoliated in whiskey.
The team used the liquid-phase exfoliation (LPE) technique, which is widely used for producing defect-free nanosheets from layered crystals.
A common way to stabilise nanomaterials in liquid is to mix two different solvents. While a blend of water and ethanol in a 60:40 ratio has been shown to be effective, the yield is too low for practical use. Amber researchers posited that by adding organic compounds, such as those found in whiskey, this could change.
Using Teeling Small Batch Irish Whiskey, the researchers found that whiskey can be effectively used as a dispersant for nanosheets of graphene and other nanomaterials to yield stable dispersions at reasonably high concentrations. These dispersions were refined into inks and printed into functioning transistors.
Contaminants from the environment where a device is made may interfere with functionality. However, the team demonstrated that devices made from layered materials are robust against external contaminants. Further, they proved that that 2D material-based devices that are permeated with whiskey compounds can still function.
“Whiskey is uniquely suited for stabilising our nanomaterials because of the maturation process it must undergo. 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,” said Prof Jonathan Coleman, Amber co-lead Investigator on the project and principal investigator in Amber and Trinity’s School of Physics.
“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.”
“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, post-doctoral researcher at Amber and Trinity’s School of Physics.
“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.”