# Graphene does water desalination **URL:** \ **Category:** Miscellaneous and Personal Stuff I Must Share\ **Created:** [April 3, 2017, 9:33pm UTC](https://boards.straightdope.com/t/graphene-does-water-desalination/783682 "2017-04-03T21:33:58Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![Quartz](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/quartz/32/267_2.png) [@Quartz](https://boards.straightdope.com/u/Quartz)\ **Post date:** [April 3, 2017, 9:33pm UTC](https://boards.straightdope.com/t/graphene-does-water-desalination/783682/1 "2017-04-03T21:33:58Z")
[This BBC article](http://www.bbc.co.uk/news/science-environment-39482342) reports a potentially world-changing discovery: graphene can be used to desalinate water by blocking the salts. Here’s hoping that they can scale it up to industrial quantities. ---
**Author:** ![HoneyBadgerDC](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/honeybadgerdc/32/1033_2.png) [@HoneyBadgerDC](https://boards.straightdope.com/u/HoneyBadgerDC)\ **Post date:** [April 3, 2017, 11:21pm UTC](https://boards.straightdope.com/t/graphene-does-water-desalination/783682/2 "2017-04-03T23:21:54Z")
Things like this are exciting to here. ---
**Author:** ![Dewey\_Finn](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dewey_finn/32/4222_2.png) [@Dewey\_Finn](https://boards.straightdope.com/u/Dewey_Finn)\ **Post date:** [April 4, 2017, 12:56am UTC](https://boards.straightdope.com/t/graphene-does-water-desalination/783682/3 "2017-04-04T00:56:58Z")
Things like this are probably exciting there as well. ---
**Author:** ![Qadgop\_the\_Mercotan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/qadgop_the_mercotan/32/83_2.png) [@Qadgop\_the\_Mercotan](https://boards.straightdope.com/u/Qadgop_the_Mercotan)\ **Post date:** [April 4, 2017, 1:23am UTC](https://boards.straightdope.com/t/graphene-does-water-desalination/783682/4 "2017-04-04T01:23:19Z")
Well, hope’s a fine thing. But I’ve heard many hopeful ideas posited before, that would revolutionize the world, cure cancer, bring peace, etc. But for the most part they fail of their promise. > [@](#): > > A UK-based team of researchers has created a graphene-based sieve capable of removing salt from seawater. > > The sought-after development could aid the millions of people without ready access to clean drinking water. > > The promising graphene oxide sieve could be highly efficient at filtering salts, and will now be tested against existing desalination membranes. Too much use of the word ‘could’ for my taste. In other words, I’ll wait for more data. But I’ll wait hopefully. ---
**Author:** ![Hari\_Seldon](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/hari_seldon/32/5173_2.png) [@Hari\_Seldon](https://boards.straightdope.com/u/Hari_Seldon)\ **Post date:** [April 4, 2017, 1:55am UTC](https://boards.straightdope.com/t/graphene-does-water-desalination/783682/5 "2017-04-04T01:55:33Z")
Unless they have reversed entropy, they will have to use more energy than the heat of fusion of salt in water to do it. But there are already processes that do it. The energy required is in the form of pressure on a semi-permeable membrane. ---
**Author:** ![Ruken](https://avatars.discourse-cdn.com/v4/letter/r/f475e1/32.png) [@Ruken](https://boards.straightdope.com/u/Ruken)\ **Post date:** [April 4, 2017, 10:26am UTC](https://boards.straightdope.com/t/graphene-does-water-desalination/783682/6 "2017-04-04T10:26:41Z")
Yeah nothing much to see here. Science Journalism strikes again. Now if it doesn’t foul in seawater, they should give me a call… ---
**Author:** ![Quartz](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/quartz/32/267_2.png) [@Quartz](https://boards.straightdope.com/u/Quartz)\ **Post date:** [April 4, 2017, 10:45am UTC](https://boards.straightdope.com/t/graphene-does-water-desalination/783682/7 "2017-04-04T10:45:13Z")
> [@Hari\_Seldon](#): > > Unless they have reversed entropy, they will have to use more energy than the heat of fusion of salt in water to do it. So what? Nobody expects something for nothing. ---
**Author:** ![Quartz](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/quartz/32/267_2.png) [@Quartz](https://boards.straightdope.com/u/Quartz)\ **Post date:** [April 4, 2017, 12:25pm UTC](https://boards.straightdope.com/t/graphene-does-water-desalination/783682/8 "2017-04-04T12:25:17Z")
> [@Hari\_Seldon](#): > > Unless they have reversed entropy, they will have to use more energy than the heat of fusion of salt in water to do it. Ah, I think I misunderstood you, and I think you have misunderstood the article. As I read it, the graphene filter will allow water molecules through, but not water molecules bound to salt molecules because those are larger, so the latter - with the salt - get left behind. ---
**Author:** ![Hari\_Seldon](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/hari_seldon/32/5173_2.png) [@Hari\_Seldon](https://boards.straightdope.com/u/Hari_Seldon)\ **Post date:** [April 4, 2017, 12:46pm UTC](https://boards.straightdope.com/t/graphene-does-water-desalination/783682/9 "2017-04-04T12:46:12Z")
> [@Quartz](#): > > Ah, I think I misunderstood you, and I think you have misunderstood the article. As I read it, the graphene filter will allow water molecules through, but not water molecules bound to salt molecules because those are larger, so the latter - with the salt - get left behind. I didn’t read the article. There is no point since they haven’t figured out how to reverse entropy. If they have, it would be far greater news than desalination of sea water. To reiterate, there are already ways to desalinate and they are used industrially. You press the salt water through a membrane that is impermeable to salt but allows the water molecules through. So meh. ---
**Author:** ![Ruken](https://avatars.discourse-cdn.com/v4/letter/r/f475e1/32.png) [@Ruken](https://boards.straightdope.com/u/Ruken)\ **Post date:** [April 4, 2017, 12:52pm UTC](https://boards.straightdope.com/t/graphene-does-water-desalination/783682/10 "2017-04-04T12:52:15Z")
The standard energy requirements of RO apply. Unlike other membranes, graphenes previously had a permeation cutoff of about 9 Angstrom, which is too big to keep solvated ions out. The innovation is that now they do what other membranes already do. ---
**Author:** ![carnivorousplant](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/carnivorousplant/32/3563_2.png) [@carnivorousplant](https://boards.straightdope.com/u/carnivorousplant)\ **Post date:** [April 4, 2017, 1:28pm UTC](https://boards.straightdope.com/t/graphene-does-water-desalination/783682/11 "2017-04-04T13:28:45Z")
Will it work in a lifeboat? ---
**Author:** ![Mavic\_Chen](https://avatars.discourse-cdn.com/v4/letter/m/e56c9b/32.png) [@Mavic\_Chen](https://boards.straightdope.com/u/Mavic_Chen)\ **Post date:** [April 4, 2017, 1:38pm UTC](https://boards.straightdope.com/t/graphene-does-water-desalination/783682/12 "2017-04-04T13:38:24Z")
> [@carnivorousplant](#): > > Will it work in a lifeboat? I was thinking the same thing, or maybe a patch sewn into a life jacket so you would be ok for water while lost at sea. ---
**Author:** ![jtur88](https://avatars.discourse-cdn.com/v4/letter/j/e9c0ed/32.png) [@jtur88](https://boards.straightdope.com/u/jtur88)\ **Post date:** [April 4, 2017, 1:41pm UTC](https://boards.straightdope.com/t/graphene-does-water-desalination/783682/13 "2017-04-04T13:41:35Z")
It would threaten to turn comfortable economics upside down for a lot of powerful vested interests, so expect plenty of roadblocks. ---
**Author:** ![carnivorousplant](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/carnivorousplant/32/3563_2.png) [@carnivorousplant](https://boards.straightdope.com/u/carnivorousplant)\ **Post date:** [April 4, 2017, 1:46pm UTC](https://boards.straightdope.com/t/graphene-does-water-desalination/783682/14 "2017-04-04T13:46:17Z")
> [@Mavic\_Chen](#): > > I was thinking the same thing, or maybe a patch sewn into a life jacket so you would be ok for water while lost at sea. I wonder how much pressure is required. ---
**Author:** ![Grey](https://avatars.discourse-cdn.com/v4/letter/g/b782af/32.png) [@Grey](https://boards.straightdope.com/u/Grey)\ **Post date:** [April 4, 2017, 2:09pm UTC](https://boards.straightdope.com/t/graphene-does-water-desalination/783682/15 "2017-04-04T14:09:55Z")
> [@jtur88](#): > > It would threaten to turn comfortable economics upside down for a lot of powerful vested interests, so expect plenty of roadblocks. :rolleyes: Damn Big Permeable Membrane, damn them all to hell. ---
**Author:** ![Dewey\_Finn](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dewey_finn/32/4222_2.png) [@Dewey\_Finn](https://boards.straightdope.com/u/Dewey_Finn)\ **Post date:** [April 4, 2017, 2:52pm UTC](https://boards.straightdope.com/t/graphene-does-water-desalination/783682/16 "2017-04-04T14:52:03Z")
> [@Hari\_Seldon](#): > > I didn’t read the article. There is no point since they haven’t figured out how to reverse entropy. If they have, it would be far greater news than desalination of sea water. I’ve asked my computer for an answer to that question. I’ll get back to you when it comes up with something. ---
**Author:** ![Folly](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/folly/32/3219_2.png) [@Folly](https://boards.straightdope.com/u/Folly)\ **Post date:** [April 4, 2017, 3:14pm UTC](https://boards.straightdope.com/t/graphene-does-water-desalination/783682/17 "2017-04-04T15:14:15Z")
> [@Dewey\_Finn](#): > > I’ve asked my computer for an answer to that question. I’ll get back to you when it comes up with something. You should probably save that question for last. ---
**Author:** ![XT](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/xt/32/456_2.png) [@XT](https://boards.straightdope.com/u/XT)\ **Post date:** [April 4, 2017, 3:21pm UTC](https://boards.straightdope.com/t/graphene-does-water-desalination/783682/18 "2017-04-04T15:21:55Z")
> [@Quartz](#): > > [This BBC article](http://www.bbc.co.uk/news/science-environment-39482342) reports a potentially world-changing discovery: graphene can be used to desalinate water by blocking the salts. Here’s hoping that they can scale it up to industrial quantities. Just need to figure out how to make it in batches larger than a roll of scotch tape now. 😉 Graphene is one of those wonder materials in a lot of ways…if they could figure out how to manufacture it in very large quantities it could seriously revolutionize materials science in a bunch of different ways. ---
**Author:** ![Grey](https://avatars.discourse-cdn.com/v4/letter/g/b782af/32.png) [@Grey](https://boards.straightdope.com/u/Grey)\ **Post date:** [April 4, 2017, 3:33pm UTC](https://boards.straightdope.com/t/graphene-does-water-desalination/783682/19 "2017-04-04T15:33:25Z")
It’s actually a graphene oxide, though they later on mention adding in a bit of straight graphene to minimize swelling between layers. ---
**Author:** ![TriPolar](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tripolar/32/3008_2.png) [@TriPolar](https://boards.straightdope.com/u/TriPolar)\ **Post date:** [April 4, 2017, 3:36pm UTC](https://boards.straightdope.com/t/graphene-does-water-desalination/783682/20 "2017-04-04T15:36:07Z")
> [@XT](#): > > Just need to figure out how to make it in batches larger than a roll of scotch tape now. 😉 Graphene is one of those wonder materials in a lot of ways…if they could figure out how to manufacture it in very large quantities it could seriously revolutionize materials science in a bunch of different ways. Graphene is to material science as Windex is to Greeks. It can do anything. I suppose graphene might make a stronger, longer lasting membrane for desalination. At $3,600 per sq. in. for graphene it has to be worth it, right? :rolleyes: [Next page](https://boards.straightdope.com/t/graphene-does-water-desalination/783682.md?page=2)