bleckster
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Desiccant that absorbs acetone?
Seems like acetone will dissolve just about any liquid, but when it comes to solids I am drawing a blank as to what solid might absorb acetone and
thus act as a disiccant when you are trying to dry a very hygroscopic salt in a desiccating chamber after you have washed it with acetone. Does
anybody have any ideas?
About the only solid I can think of that is soluble in acetone is sodium iodide, however that would be quite an expensive option.
[Edited on 19-12-2013 by bleckster]
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WGTR
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Is drying the salt in a vacuum chamber/oven or vacuum desiccator not an option?
Does your salt absorb moisture only below a certain temperature? If so, then maybe putting it directly into a hot oven would work.
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IrC
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Either Diatomaceous earth or Kapok is used inside Acetylene tanks to absorb Acetone which is used to keep the Acetylene dissolved, thus reducing the
tendency of Acetylene to explode. I wonder if Diatomaceous earth or Kapok would work in your chamber?
"Science is the belief in the ignorance of the experts" Richard Feynman
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bleckster
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WGTR: I think you missed where I said that I was drying my salt in a desiccating chamber. ;-)
I also should have mentioned that I was looking for the most OTC solution possible--ie. cheap and easy to find at the hardware store.
And I think I found my own answer:
Journal of the Society of Chemical Industry, Volume 12
Apparently boric acid is "freely soluble" in acetone. Boric acid is sold as roach killer in the hardware store!
[Edited on 19-12-2013 by bleckster]
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crazyboy
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Quote: Originally posted by bleckster  | WGTR: I think you missed where I said that I was drying my salt in a desiccating chamber. ;-)
[Edited on 19-12-2013 by bleckster] |
WGTR was specifically asking if drying under vacuum was an option for you. I am inclined to agree that drying under vacuum is the most efficient way
to remove acetone
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violet sin
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So you intend to put x-acetone mixture in the dec-chamber with boric acid to pull the solvent out then? Interesting. Though solubility of "x" versus
H3BO3 in acetone will have to be favorable. Is the x component too fragile to be heated to remove the acetone, or are you just trying to save it for
later use? I will be interested to hear how this works for ya.
I would imagine at low temp dry sand or similar small particle inert material would hold on to the volatile solvent by physical form alone. To what
degree I have no clue. And I could be wrong on this entirely but most porous materials get at lead damp when confined with vapor.
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zed
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Ummm. Last time I had to remove acetone from a hygroscopic salt (an amine hydrochloride), I just gently blew a current of hot dry air onto the salt,
as I sifted it from a wire strainer. A few run throughs, and it was pretty well dried.
Later analysis showed the final product to contain about 2% acetone, and negligible H2O. I suppose, I could have removed the last traces of acetone
via vacuum, but the product proved adequate for my purposes, as it was.
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Bot0nist
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I agree with zed and others. If your isolate is not thermaly sensitive, use evaporation via hot clean dry air, else rely on acetones volatility and
use a vacuum...
U.T.F.S.E. and learn the joys of autodidacticism!
Don't judge each day only by the harvest you reap, but also by the seeds you sow.
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bleckster
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Sorry, yes it's a vacuum desiccating chamber, however even if it wasn't, a desiccant should eventually work to absorb your volatile compound, right?
Especially acetone, as it's so much more volatile than water.
Regarding the solubilities between the salt I am drying and the desiccant--the salt is insoluble in acetone to begin with (ie. that's why I used
acetone to "wash" it in the buchner filter)--there are just traces of it remaining afterward and I can tell the product isn't completely bone dry just
from the texture.
My oven is gas, not electric, and acetone is very flammable, so that's a no-go. :-)
When you guys say hot hair, I take it you're talking about a blow dryer or a heat gun set on low...? I suppose I could give your method a try, zed.
But I'd have to acquire a new sifter (I have a rule, never use the food utensils for chemistry--don't care what it is).
Btw, boric acid is NOT "freely soluble" in acetone, bleh. $5 wasted. I should have double checked this because wikipedia says it's "very slightly
soluble".
I would still like to find a desiccant that can be used for this purpose--I just think it would be a good thing to know about, don't you?
I suppose I could actually use the sodium iodide I have, and then afterward leave it on a paper plate in the open air for the acetone to evaporate
off. Since it isn't hygroscopic, it won't pick up moisture from the air.
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bleckster
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Final report: apparently boric acid was "slightly soluble" enough to absorb the acetone fumes overnight as my salt no longer smells of it and is quite
dry and nearly clumping now.
That link I posted before also said that oxalic acid is soluble in acetone and that can be found OTC in some hardware stores as well--so that might
also be something to try some day (I just used up the last of what I had so for me it'll have to be another day).
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