[bbro1997]

In the fairly distant future, I plan on isolating cesium in a vacuum via electrolysis. I am building the vacuum chamber myself, and I need it to be powerful enough to get the air concentration low enough to where there will be little to no reactivity with the cesium. Does anyone know of an approximate air concentration where cesium will not explode, spontaneously combust, or tarnish rapidly? The cesium will only need to be in the vacuum for a few minutes max before I submerge it in an inert oil.

[curiouscat]

The cesium will only need to be in the vacuum for a few minutes max before I submerge it in an inert oil.

How do you plan on doing the manipulation in the vacuum?

[Borek]

I plan on isolating cesium in a vacuum via electrolysis

And what are you going to electrolyze?

[discodermolide]

You probably will not be able to reach an efficient vacuum. What sort of vacuum pump do you have?

[bbro1997]

I plan on manipulating the inside of the vacuum with layers of gloves bolted and sealed to the walls of the chamber. I'm already going over all of the structural aspects on another forum.

Currently I am only using pure cesium as a reference point as to how potent of a vacuum I need to safely store it. I would never need a vacuum more pure than what is necessary to keep cesium from reacting. However I do plan on isolating cesium eventually, most likely via electrolysis of molten CsCl.

As for the vacuum pump, I do not know. My dad owns one that I could use, but it is quite old and possibly broken (he lent it to a friend who may have accidentally broke it). That is the reason I came here, is to determine how powerful a pump I would need to suck sufficient air out of a 1 cubic foot box to keep cesium from reacting. I don't mind a little tarnish, I just don't want the stuff to explode, spontaneously combust, or be instantly contaminated.

[discodermolide]

OK. I would try this as follows because you are never going to get it done in a vacuum.
You need to evacuate the container with the apparatus inside it, then release the vacuum with nitrogen or better argon. Do this evacuation release two or three times, finally leaving the apparatus under an inert gas. Argon is better because it is heavier than air and will be slow to diffuse out allowing you to work with the cell. You can always keep the argon slowly flowing over the top.
Think about it. I don't know if you can get argon cylinders where you are, but argon is great for this type of application.

[bbro1997]

For what reason would it not work in a vacuum? Argon gas can get expensive if it is frequently used in large quantities. An empty tank to store it in would cost around $200 alone.

[Enthalpy]

What happens with Cl₂ when you electrolyse CsCl? If Cs is gaseous and meets Cl₂...

I've just read that propylene carbonate, a mass-produced industrial compound for lithium batteries, permits to dissolve alkaline chlorides and electrolyse them.
http://en.wikipedia.org/wiki/Propylene_carbonate
what's very nice: caesium is denser than propylene carbonate, so it would be protected from the gas.

[discodermolide]

For what reason would it not work in a vacuum? Argon gas can get expensive if it is frequently used in large quantities. An empty tank to store it in would cost around $200 alone.

It would work in a vacuum but it makes life more difficult.
It is easier to work under normal pressure, so argon costs $200, not too expensive then.

[bbro1997]

What happens with Cl₂ when you electrolyse CsCl? If Cs is gaseous and meets Cl₂...

I've just read that propylene carbonate, a mass-produced industrial compound for lithium batteries, permits to dissolve alkaline chlorides and electrolyse them.
http://en.wikipedia.org/wiki/Propylene_carbonate
what's very nice: caesium is denser than propylene carbonate, so it would be protected from the gas.

This is interesting; someone else above brought up a good point above that I had overlooked, that cesium would vaporize at the temperatures needed to melt CsCl. I imagine that this may solve that issue. As for the chlorine gas that is produced, it would be immediately extracted, as the vacuum pump would remain running.

[bbro1997]

So I did some more research, and apparently it is quite easy to synthesize some propylene carbonate at home. You just need some propylene glycol and urea along with some kind of catalyst (usually ZnO). These are all cheap, easily obtainable substances. However I would like to know more about how this process works before I jump into it. Is anyone familiar with the reactants/products of the reaction between propylene glycol, urea, and ZnO?