In an unlikely marriage of science, researchers have found a way to produce high-quality graphene using Irish whiskey.

You would think a team of researchers turning to drink would mean bad news for science, but in fact it is leading to some exciting developments in the field of materials science. Researchers from the SFI Advanced Materials and Bioengineering Research (AMBER) centre at Trinity College Dublin have revealed a new way to produce graphene using Irish whiskey.

One increasingly popular method of producing the atom-thick, highly conductive ‘wonder material’ is liquid-phase exfoliation (LPE). Deemed to one of the most efficient and scalable means for producing high-quality graphene sheets, LPE is very versatile and has now been applied to a range of common layered materials including graphite, talcum powder and clay.

As part of a study published to 2D Materials, the AMBER researchers showed that graphene nanosheets free from defects can be exfoliated in Irish whiskey as well as inks that can be printed into nanosheet networks for use in electronics.

LPE is increasingly being used for low-cost electronic devices and sensors such as RFID tags, data storage and pixels in OLED TVs.

Why whiskey?

One of the most common ways of stabilising nanomaterials in a liquid or ink is to mix two different solvents. Previously, a blend of water and ethanol in a 60 to 40 ratio was shown to work, but was at too low a yield to be practical. However, the AMBER researchers tested the benefits of adding some organic compounds commonly found in commercial spirits such as whiskey.

The results showed that Irish whiskey is effective as a dispersant for nanosheets of graphene and other nanomaterials, yielding stable dispersions at reasonably high concentrations. The resulting dispersions were then refined into inks and printed onto working transistors.

This, the researchers said, proves that 2D devices permeated in whiskey compounds can still function and are robust against external contaminants.

Explaining the role Irish whiskey plays in the process, co-lead investigator of the study, Prof Jonathan Coleman, said: “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.

“Other clear spirits like vodka are ostensibly just water and ethanol so they lack the broad compound profile inherent to whiskey. These compounds are what help to stabilise our nanomaterials.”

The researchers have said it is still possible to boost the graphene nanosheet’s performance over time, but the fact they function at all in whiskey is a substantial breakthrough.