Graphene still shines on us with its strength and versatility – exciting new applications are constantly being discovered for it, and now scientists have found a way to manipulate the wonder material to make it work. can filter out inconsistencies out of the water.
The bilateral material with carbon atoms has previously been studied as a means of purifying water, but the new method may still offer the most promising method. It is responsible for exploiting the so-called van der Waals gaps: the tiny spaces that appear between 2D nanomaterials when coated on top of each other.
These nanochannels can be used in a number of ways, which scientists are now studying, but graphene strains cause a problem for filtration: liquid must spend much of its time traveling on the horizontal plane, rather than the straight one, which would be much faster.
To solve this problem, the team behind the new study used an elastic substrate to examine the graphene level to a microscopic layer of peaks and valleys. That means liquid can go down the side of a peak directly, instead of walking over the open areas horizontally (all at the nanoscale, of course).
(Brown University)
“When you start peeling the graphene, you squeeze the sheets and channels out of the plane,” says materials scientist Muchun Liu of the Massachusetts Institute of Technology (MIT).
“If you write it a lot, the channels end pretty much straight.”
To complete the effect, the graphene and substrate are bound in epoxy material, before the tops of the peaks and the bases of the valleys are cut off. It gives the liquid a faster route through graphene while still allowing filtration to take place.
Liu and her colleagues have named the new products VAGMEs (collateral graphene membrane), and further down the line they have found uses far beyond making safe drinking water.
“What we end up with is an organ with those short, narrow channels that only very small molecules can pass through,” says chemical engineer Robert Hurt, of Brown University.
“So, for example, water can pass through, but organic pollutants or some metal ions would be too big to pass through. So you could filter that out.”
The next step is to implement and work out a practical seeding system, but the theory is strong. The material passed one of the first experiments by allowing a valve of water to flow through, capturing larger hexane molecules.
Finally these VAGMEs could find uses in industrial or domestic filtration systems, the scientists say – just one of many promising ways graphene is being used in a number of different scientific fields.
As for the nanochannels that work between thin 2D materials like graphene, there is plenty of potential here as well, according to the experts. The closer scientists look at these nanomaterials, the more they discover.
“In the last decade, an entire field has emerged to study the spaces between 2D nanomaterials,” Hurt says.
“You can grow things in there, you can store things in it, and this range of nanofluidics shows where you use those channels to filter some molecules while allowing others to go through. “
The research was published in Nature Communication.