I have a custom-built electrolytic membrane cell that uses a standard sandwich of Nafion and other materials as the membrane. Recently, the membrane was damaged, and is unusable. So, until I can properly replace it, what common materials (excluding asbestos or mercury) can function as a working, temporary ion-permeable membrane that will prevent gas mixing and minimize back transfer of Cl– and –OH ions? It has to be something I can fit between the two adjoining cells (like a windowpane), and something that’s readily available and cheap. The cell is sealed, so a typical salt bridge is not an option. Perhaps a thin, sheet of one of our common plastics?
This cell is used to demonstrate to students the chloralkali process for production of NaOH, chlorine and hydrogen gas from a brine.
Example cell layout, from Wiki: http://upload.wikimedia.org/wikipedia/en/thumb/2/29/Chlor_alkali_cell.jpg/250px-Chlor_alkali_cell.jpg
Many thanks in advance.
C’mon. Someone has to know this. :)
One Response
Nafion and similar membranes were carefully optimized to reduce cell resistance and restrict chlorine gas mixing with OH- ions. It is not likely that there can be a cheap exact substitute or everyone in the chloralkali industry would just use that.
I have seen cellophane used for dialysis membranes but am not sure if the pore size is suitable for this. That is the best I could think of.