The BBC reports:
A UK-based team of researchers has created a graphene-based sieve capable of removing salt from seawater.
Manufacturing graphene-based barriers on an industrial scale has been a problem in the past, but this new sieve promises to be more affordable, yet still effective in filtering salts, and will now be tested against existing desalination membranes.
Reporting their results in the journal Nature Nanotechnology, scientists from the University of Manchester, led by Dr Rahul Nair, shows how they solved some of the challenges by using a chemical derivative called graphene oxide.
Isolated and characterised by a University of Manchester-led team in 2004, graphene comprises a single layer of carbon atoms arranged in a hexagonal lattice. Its unusual properties, such as extraordinary tensile strength and electrical conductivity, have earmarked it as one of the most promising materials for future applications.
[...] Previous work had shown that graphene oxide membranes became slightly swollen when immersed in water, allowing smaller salts to flow through the pores along with water molecules.
Now, Dr Nair and colleagues demonstrated that placing walls made of epoxy resin (a substance used in coatings and glues) on either side of the graphene oxide membrane was sufficient to stop the expansion.
(Score: 5, Insightful) by bob_super on Monday April 03 2017, @11:34PM (2 children)
Marvelous Graphene, isn't there anything you can't do, besides being commercially viable?
(Score: 4, Funny) by butthurt on Tuesday April 04 2017, @01:35AM
Henry David Thoreau is best known as an author, but "for most of his adult life" he worked in his family's factory, which made graphene generators.
https://en.wikipedia.org/wiki/Thoreau#Return_to_Concord.2C_1836.E2.80.931842 [wikipedia.org]
(Score: 2) by seeprime on Tuesday April 04 2017, @06:43AM
The cost of producing the sheets is exceeded only by the cost of coating them with an epoxy that has little to no adhesion to graphene. Applying a silane to get the epoxy to adhere to graphene adds even more cost. "That tricks never works" -Rocky to Bullwinkle
(Score: 3, Insightful) by butthurt on Monday April 03 2017, @11:50PM
The BBC article quotes one of the researchers as saying
This is our first demonstration that we can control the spacing [of pores in the membrane] and that we can do desalination, which was not possible before.
The words in square brackets are the BBC's and I think they're erroneous. The abstract of the journal article uses the word "laminates" and the figures show that the water flows between sheets of graphene oxide.
(Score: 0) by Anonymous Coward on Tuesday April 04 2017, @01:10AM (5 children)
and always will be.
(Score: 1, Interesting) by Anonymous Coward on Tuesday April 04 2017, @10:27AM (4 children)
People thought the same of asbestos... which is what I'm always wondering with chemicals forming small fibres... How safe is all this? Anyone some insight/experience?
(Score: 4, Informative) by kaszz on Tuesday April 04 2017, @03:39PM (3 children)
Epoxy has one component of Bisphenol-A which is a hormone disruptor that increases risk for cancer etc significantly. Another issue relates to what you write about asbestos. Hard fibers that breaks away and ends up in the body where it pierces cells that makes them inflamed which cause their cell division to bad.
Graphene is useful. Mixing it with the food chain is probably a really bad idea.
(Score: 1, Funny) by Anonymous Coward on Tuesday April 04 2017, @09:10PM (2 children)
After having desalinized it using graphene you distill the water, EZ.
(Score: 2) by kaszz on Wednesday April 05 2017, @02:31AM
If you distill the water later, why use desalination to begin with?
(Score: 0) by Anonymous Coward on Wednesday April 05 2017, @06:13PM
I'll take your advice.....with a grain of salt.
(Score: 0) by Anonymous Coward on Wednesday April 05 2017, @08:22PM
No matter what filter you use, it still requires the salt water be pumped to 350 psi to get it to overcome osmotic pressure and flow through the filter. Sea water desalinization is not economical because of the energy input required, not the quality of the filter.