Sciencemadness Discussion Board

Ideal Container for Electrolysis

DFliyerz - 9-1-2015 at 15:02

I've been working to make potassium chlorate and sodium chlorate/perchlorate with a powerful power supply (5a/30v) and a mason jar with holes drilled in the top for electrodes and a hole for gasses to escape without too much water evaporating. With my first try with potassium chloride, I got about 2.5a and maxed out voltage, ending with a bit of corroded metal in the product. I next tried a more concentrated solution of sodium chloride, quickly maxing out at 5a and about 20v. Before this I coated the metal in a few layers of a spray-on acrylic coating, hoping to prevent it from oxidizing. Lo and behold, I was greeted to much more oxidation and destruction of the lid than before! I've pretty much given up on mason jars with metal lids at this point, and was wondering what the ideal type of container would be to run this reaction.

gdflp - 9-1-2015 at 15:28

What electrodes are you using? 30V is way overshooting it, 12V will make perchlorate just fine, higher voltages will only stress and damage your electrodes. As for a container, reagent bottles with teflon lids work great as they don't corrode and are made of borosilicate glass which withstands the electrolyte more effectively.

bottle-2-jpg_w800_h600_fit[1].jpg - 63kB

[Edited on 1-10-2015 by gdflp]

macckone - 9-1-2015 at 15:36

PVC is your friend. Acrylic also works.

Molecular Manipulations - 9-1-2015 at 15:39

I use clear 4" PVC pipe. The top and bottom are made of PVC caps with the sealant. So far no leaks.
You're using way too many volts, try 5-7 unless you want to ruin your anode.
What kind of anode do you have?
I use rhodium MMO and it has worked fine for over a year.
Can you get a better power supply? 20 volts will not work.

aga - 9-1-2015 at 16:06

tupperware :)

DFliyerz - 9-1-2015 at 18:10

I use MMO as the anode and graphite as the cathode.

gdflp - 9-1-2015 at 18:48

In that case, the voltage should not exceed 5V as this will damage the anode and severely shorten it's lifetime. Graphite will do just fine at 12V, it might just corrode a little faster.

DFliyerz - 9-1-2015 at 19:01

Quote: Originally posted by Molecular Manipulations  
I use clear 4" PVC pipe. The top and bottom are made of PVC caps with the sealant. So far no leaks.
You're using way too many volts, try 5-7 unless you want to ruin your anode.
What kind of anode do you have?
I use rhodium MMO and it has worked fine for over a year.
Can you get a better power supply? 20 volts will not work.


Where did you find that clear, thick PVC? Also, have you run into any problems with high temperatures exceeding the plastics limit?

Molecular Manipulations - 9-1-2015 at 19:57

Home Depot IIRC, but now that I think about it, I'm not sure it's PVC, it was in the PVC isle, but I didn't check for sure. Either way it works, and I've had no problem with melting or softening at high temperatures.
That may be due to the fact that I run the cell at about 60 deg. C instead of the recommended 70-85.
It seems to work fine at the lower temp, but I boil it before extracting the goods.
I would use stainless steel rather than graphite for the cathode, but either will work.

IrC - 9-1-2015 at 21:24

They also make clear Acrylic tubing but I have seen none with thick walls like the clear schedule 40 PVC.

http://www.usplastic.com/catalog/item.aspx?itemid=39382

I imagine the thick walls aid in maintaining strength even when fairly warm so the PVC appears to be the better choice.

34100p.jpg - 27kB

DFliyerz - 10-1-2015 at 12:32

Quote: Originally posted by IrC  
They also make clear Acrylic tubing but I have seen none with thick walls like the clear schedule 40 PVC.

http://www.usplastic.com/catalog/item.aspx?itemid=39382

I imagine the thick walls aid in maintaining strength even when fairly warm so the PVC appears to be the better choice.




It looks good, but $210 for the minimum amount, that's steep...

NeutralIon - 10-1-2015 at 13:33

I've had good results making chlorates in plastic paint mixing containers -- generally found in the paint section of hardware stores. The brand I've used was "Mix' n Measure", made by Encore Plastics. They come in various sizes -- I found the 2.5qt size best for the batches I made. Not sure what type of plastic they are but I think it's polyethylene -- whatever it is it is not attacked by the chlorate. They're cheap and you can get a cover for them.

IrC - 10-1-2015 at 14:47

Quote: Originally posted by DFliyerz  
It looks good, but $210 for the minimum amount, that's steep...


Logically one would go to a Home Depot or similar outlet and only buy the needed quantity. I posted the link as a source of information on the clear PVC not as a place to buy it. Unless of course your needing a large quantity.

pepsimax - 3-2-2015 at 23:39

Quote: Originally posted by DFliyerz  
Quote: Originally posted by IrC  
They also make clear Acrylic tubing but I have seen none with thick walls like the clear schedule 40 PVC.

http://www.usplastic.com/catalog/item.aspx?itemid=39382

I imagine the thick walls aid in maintaining strength even when fairly warm so the PVC appears to be the better choice.




It looks good, but $210 for the minimum amount, that's steep...


Have you tried computer watercooling suppliers? They sell acrylic tubing for moderate temps.