i want to use nafion for desalination.i have a setup that contains two continuous streams of salty and salt free(Passing through Nefion) one side of nafion(cation exchange) is in contact with saline solution (NaCl) and it uses the driving force of the electric potential to transport the ion.But by applying the voltage, no water flows from the nafion.
Does anyone know why water doesn't pass through nafion?
Is it possible the water to pass through the nafion with the conditions mentioned above?
(Note: Only one side of the Nefion is in contact with the solvent and the other side is not in contact with any fluid.)
https://pdfs.semanticscholar.org/c6c5/e0c19ab78cae98bb643b94c8031c2139e307.pdf
dear Khalid Turki Rashid
Thanks for your Response And submit the article link.
but this article can not help me,Because this is for fuel cell operating conditions, it is different from my operating conditions.
I explained the operating conditions of my work above, And I'm looking to find water permeation from Nafion in this situation.
Is this a well known process you are trying to follow? Because I would not expect water to pass though Nafion. It has a tetrafluoroethylene (teflon) backbone with a strongly polar channel (sulphonic acid group). It will exchange cation when dipped in an ionic solution. In my limited knowledge water should not pass thorough Nafion.
Dear Tuhin Khan
Thanks for Response.
As you know and say, nafion composed of a hydrophobic matrix consisting of a tetrafluoroethylene backbone and perfluoroalkyl ether side chains that account for ∼90 vol % and very hydrophilic sulfonic acid groups that account for ∼10 vol %. Water interacts with the hydrophilic sulfonic acid groups; water sorption hydrates the sulfonic acid groups swelling the hydrophilic domains that are embedded in the hydrophobic matrix. Transport of water is confined to the hydrophilic domains.Water sorption swells the hydrophilic domains, creating greater volume for water to move, which increases the water diffusion rate. (Image attached)
In addition, I have also seen a lot of papers that have worked on water transfer in nafion.But with different operating conditions, for example, on both sides of the membrane is fluid. But under my operating conditions, I have a fluid side.
I want to know if nafion the water flows through my operational conditions, too?
Thanks for your response. I understand your point. I think you need pure water in other side of the membrane. Probably the high surface tension of water is preventing it to leave the membrane. A little water on the other side might accelerate the process.
- Badges
- Science topic
- Similar topics
- Chemistry
- Sulfites
- Inorganic Chemistry
- Inorganic Chemicals
- Salts