Is there a material that ions can pass through but water can’t?

I was wondering whether there is a material that can pass ions (such as the ions existing in seawater) but not water. I am aware that water molecules are smaller, so they can pass through some materials but ions don’t. However, is there a material that is the opposite? Or is there a hydrophobic material that can be used as a coating for a porous material, and doing the same job by preventing water from passing but allow ions to pass through it?


Thanks in advance




There are so many materials that allow the passage of ions but not water. They are called ion-exchange membranes. I believe you are interested in water purification based on your previous posts. The trick is to attract the ions on one side. Student always tend to forget that a solution must remain electrically neutral by all means. If you want a certain ion to leave water, you must provide another ion of the same charge that has left the solution.


An example is given here [Image below](http://www.astom-corp.jp/en/product/02.html)


[![enter image description here](https://i.stack.imgur.com/NjaDC.png)](https://i.stack.imgur.com/NjaDC.png)


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