Scientists from Singapore and Belgium have successfully altered the properties of water, making it corrosive enough to etch diamonds.
The team achieved this by attaching a layer of graphene on diamond and heating to high temperatures – water molecules trapped between them become highly corrosive.
While diamond is known to be a material with superlative physical qualities, little is known about how it interfaces with graphene, an one-atom thick substance composed of pure carbon.
The researchers sought to explore what happens when a layer of graphene, behaving like a soft membrane, is attached on diamond, which is also composed of carbon. To encourage bonding between the two rather dissimilar carbon forms, the researchers heated them to high temperatures.
At elevated temperatures, the team noted a restructuring of the interface and chemical bonding between graphene and diamond. As graphene is an impermeable material, water trapped between the diamond and graphene can’t escape. At a temperature that is above 400 degree Celsius, the trapped water transforms into a distinct supercritical phase.
“We show for the first time that graphene can trap water on diamond, and the system behaves like a ‘pressure cooker’ when heated. Even more surprising, we found that such superheated water can corrode diamond. This has never been reported,” said Prof Loh Kian Ping from the National University of Singapore, senior author of a paper published in the journal Nature Communications.
Due to its transparent nature, the graphene bubble-on-diamond platform provides a novel way of studying the behaviors of liquids at high pressures and high temperature conditions, which is traditionally difficult.
“The applications from our experiment are immense. In the industry, supercritical water can be used for the degradation of organic waste in an environmentally friendly manner. Our work can be also applicable to the laser-assisted etching of semiconductor or dielectric films, where the graphene membrane can be used to trap liquids,” Prof Loh said.
The discovery has wide-ranging industrial applications, from environmentally-friendly degradation of organic wastes to laser-assisted etching of semiconductor or dielectric films.
Bibliographic information: Candy Haley Yi Xuan Lim et al. 2013. A hydrothermal anvil made of graphene nanobubbles on diamond. Nature Communications 4, article number: 1556; doi: 10.1038/ncomms2579