Junk_Enginerd
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Separating cloudy suspension of Benzyl Alcohol on water
I made a working lava lamp from scratch and I'm so fucking pleased with myself. However, somewhere in the process I accidentally muddied it up. The
liquids are Benzyl Alcohol to act as lava, and plain water that I've added table salt to until the S.G. was right.
Is there a process I could perform to separate them? It doesn't seem like it's going to happen on its own. Also, is there something I could add to it
to make the mixture more resistant to this happening?
I could of course just pour out the water and replace it, but I'd lose a lot of the Benzyl Alcohol doing this, and all I have is in the lamp...
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unionised
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Adding a lot of salt will make the water phase denser and that should help separate the liquids.
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clearly_not_atara
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Shouldn't you want more strongly immiscible liquids? Anisole/water seems like a better choice than BnOH. Anisole has an SG of 0.995 so might not be
quite dense enough... or it might work with very pure water. Maybe a dye would be enough to bring up the density of the np phase in that system.
Alternatively, you could replace the NaCl with K2SO4 according to the:
http://en.wikipedia.org/wiki/Hofmeister_series
and see if that doesn't salt BnOH a bit stronger
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Junk_Enginerd
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I'll give that a shot, thanks. In an attempt to be a little non-invasive, I tried chilling it. That also helped a bit, I assume by the same mechanism.
Quote: Originally posted by clearly_not_atara  | Shouldn't you want more strongly immiscible liquids? Anisole/water seems like a better choice than BnOH. Anisole has an SG of 0.995 so might not be
quite dense enough... or it might work with very pure water. Maybe a dye would be enough to bring up the density of the np phase in that system.
Alternatively, you could replace the NaCl with K2SO4 according to the:
http://en.wikipedia.org/wiki/Hofmeister_series
and see if that doesn't salt BnOH a bit stronger |
I would indeed have preferred something less miscible. I'm not sure about any way of making it work if it's not denser than water though, since water
can easily be made denser with any salt to match the densities, but the other way around is more difficult. The venn diagram of something that's:
Immiscible with water
Denser than water
Simple enough to synthesize or easily aquired otherwise
results in a pretty damn small selection. Benzyl alcohol was the best compromise I could find, it's also nice that it's not overly toxic and
practically non volatile.
Dioxane or chloroform might have ticked those boxes as well, but the whole thing would have had to be thoroughly sealed, and under considerable
pressure since the basic mechanism of the lamp involves heating.
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DraconicAcid
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I think dioxane is miscible with water, isn't it? Just like THF?
If you had something like anisole, you could add a small amount of chloroform to increase the density. Alternatively, you could halogenate something
aromatic to increase the density of that compound without increasing its water solubility.
Please remember: "Filtrate" is not a verb.
Write up your lab reports the way your instructor wants them, not the way your ex-instructor wants them.
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