Graphene May Be the Key to Drinkable Ocean Water

Researchers develop a graphene-based membrane that may make large-scale desalinization possible.

graphene lattice
Image source: Perig/Shutterstock

Graphene is absolutely amazing stuff, the lightest, strongest stuff we know of. According to the University of Manchester:

  • It's ultra-light, yet immensely tough.
  • It's 200 times stronger than steel, but it is incredibly flexible.
  • It's the thinnest material possible as well as being transparent.
  • It's a superb conductor and can act as a perfect barrier - not even helium can pass through it.

  • Scientists the world over are envisioning uses for the one-carbon atom thick, essentially two-dimensional allotrope, including:

  • Incredibly-fast storage
  • Instantaneous phone charging
  • Clumping radioactive waste for easy disposal
  • Super-capacitors that would make batteries obsolete
  • And now, a team of scientists at University of Manchester have developed a solution to one of our most serious and vexing problems: Efficiently turning salty seawater into potable H2O. It could lead to a way, as Science Alert puts it, “to quickly and easily turn one of our most abundant resources, seawater, into one of our most scarce — clean drinking water." The UN says that 1.2 billion people currently live in areas with insufficient drinkable water.

    Graphene was first produced in 2004 when two scientists at The University of Manchester, Andre Geim and Kostya Novoselov stripped away layers of graphite one at a time using Scotch tape(!) until only a single layer, graphene, remained.

    The new technique uses a new graphene-oxide membrane as a sieve that filters out salt molecules from water.

    Graphene membrane (UNIVERSITY OF MANCHESTER)

    The idea of using graphene-oxide membranes for desalinization isn't new — their atom-scale pores are perfect for the job — but this is the first successful attempt to make it happen. When previous membranes were immersed in water, they'd absorb it, swelling up and enlarging the pores, ruining their ability to catch tiny salt molecules. The University of Manchester's team, led by Rahul Nair, has solved this problem by building walls of epoxy resin around the membrane to keep its atoms dry when underwater.

    (INSTITUTE OF PHYSICS)

    Now that they have that issue resolved, as Nair told Phys.org, "Realization of scalable membranes with uniform pore size down to atomic scale is a significant step forward and will open new possibilities for improving the efficiency of desalination technology."

    While still in the experimentation stage, Nair says his team's results bode well for manufacturing membranes large enough to be deployed on a large scale. “This is the first clear-cut experiment in this regime. We also demonstrate that there are realistic possibilities to scale up the described approach and mass produce graphene-based membranes with required sieve sizes."

    As exciting a solution as this may prove to be for generating drinkable water, the team says water's just the beginning when it comes to purpose-built sieves using graphene. "The developed membranes are not only useful for desalination, but the atomic scale tunability of the pore size also opens new opportunity to fabricate membranes with on-demand filtration capable of filtering out ions according to their sizes," says Jijo Abraham, who co-authored the research with Nair and Vasu Siddeswara Kalangi.

    Weird science shows unseemly way beetles escape after being eaten

    Certain water beetles can escape from frogs after being consumed.

    R. attenuata escaping from a black-spotted pond frog.

    Surprising Science
    • A Japanese scientist shows that some beetles can wiggle out of frog's butts after being eaten whole.
    • The research suggests the beetle can get out in as little as 7 minutes.
    • Most of the beetles swallowed in the experiment survived with no complications after being excreted.
    Keep reading Show less

    Stressed-out mothers are twice as likely to give birth to a girl

    New research from the University of Granada found that stress could help determine sex.

    Photo: Romolo Tavani / Adobe Stock
    Surprising Science
  • A new study found that women with elevated stress before, during, and after conception are twice as likely to deliver a girl.
  • One factor could be that sperm carrying an X chromosome are better equipped to reach the egg under adverse conditions.
  • Another factor could be miscarriage of male fetuses during times of stress.
  • Keep reading Show less

    The cost of world peace? It's much less than the price of war

    The world's 10 most affected countries are spending up to 59% of their GDP on the effects of violence.

    Mario Tama/Getty Images
    Politics & Current Affairs
    • Conflict and violence cost the world more than $14 trillion a year.
    • That's the equivalent of $5 a day for every person on the planet.
    • Research shows that peace brings prosperity, lower inflation and more jobs.
    • Just a 2% reduction in conflict would free up as much money as the global aid budget.
    • Report urges governments to improve peacefulness, especially amid COVID-19.
    Keep reading Show less
    Surprising Science

    The evolution of modern rainforests began with the dinosaur-killing asteroid

    The lush biodiversity of South America's rainforests is rooted in one of the most cataclysmic events that ever struck Earth.

    Quantcast