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unionised
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"The eutectic mixture of Na and K metals melts at room temperature or only just above, I believe."
Must be chilly in your place, that stuff melts 12 degrees below freezing.
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MadHatter
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Glycerine
Glycerin will freeze on a block of ice. It stays solid below 20 C (68 F). Just an idea.
From opening of NCIS New Orleans - It goes a BOOM ! BOOM ! BOOM ! MUHAHAHAHAHAHAHA !
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neutrino
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Theoretically, it will. The only problem is that glycerin is one of those things that is very hard to crystalize.
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If_6_was_9
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Coconut oil
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hodges
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Freezing/Melting Observations
I recently obtained some new chemicals, including DMSO and 99% acetic acid. I put a few ml of each in two test tubes and put them in the
refrigerator.
The DMSO froze quickly. The acetic acid remained a liquid. So I put the acetic acid in the freezer (-20C). It still did not freeze. I stirred it
with a plastic dropper and it froze.
I watched the behavior of these solids as I warmed the test tubes with my hand. The acetic acid melted rapidly, starting to form liquid before I even
put my hand on the test tube. It was all melted in a minute. The DMSO, on the other hand, stayed solid for a long time, and felt cold to my hand the
whole time. I have not looked up the heats of fusion for these two substances but I would guess based on my tests that DMSO has a far higher heat of
fusion than acetic acid. DMSO might prove practical for storing heat/cold. I doubt acetic acid would be.
Hodges
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12AX7
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Hmm, so supersaturated solutions aren't restricted to metal acetates, eh?
Tim
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DeAdFX
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Tert Butyl Alcohol The stuff is sometimes a frozen block or a clear liquid at room temp
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ethan_c
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this is an old, old thread, but…
cesium, anyone?
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JohnWW
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Caesium is too dangerous to handle - must not be exposed to any gases or liquids other than argon and aliphatic hydrocarbons. How about gallium,
instead? (M.pt. 29ºC), or, for a lower melting point, eutectic mixtures of it with indium, bismuth, tin. Mixing it with mercury would also work, but
there would be the toxicity problem.
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unionised
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Caesium and gallium were 2 of the early sugestions Did you read the thread before posting those replies?
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ethan_c
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| Quote: | Originally posted by unionised
Caesium and gallium were 2 of the early sugestions Did you read the thread before posting those replies? |
Woop. I did, but I didn't see neutrino's single-sentence mention of Cs.
I just like the idea more than anything. I really want to spend a paycheck on a big ol' ampoule as a present to myself.
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Fleaker
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I'm pretty sure dodecane melts at about 22.4C always solid whenever I look at the bottle in the laboratory.
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unionised
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Since the literature value for the melting point of dodecane is about 12 degrees below freezing I think you need a better heater in the lab.
Are you sure you don't mean docosane (bpt 224 @15mmHg)
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Fleaker
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Gah, not dodecane, I meant *heptadecane* (at least I was right about the decane part  , but still 5 carbons off).
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IrC
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I made a mix of tin, bismuth, gallium, and various and sundry other metals which melts just sitting on my table.
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The_Davster
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In what ratio?
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IrC
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Who knows, just playing around adding this and that. I have lots of the metals. Oh yeah, I forgot, I put Indium in there also. Don't ask how much, it
was not a scientific experiment, just boredom.
If it did something super futuristic I am sure I could do more controlled mixing and recreate it. Was trying to make ways to mirror my super thin
carbon to float on top my magnets and make a cool sensor for something or other.
I am thinking it was around 45 percent Bismuth, 10% Tin, 30% Gallium, 15% Indium. It is also in the high 80's to low 90's in here (I get lung
infections every summer around July if I run too much AC all the time, so I shut it off every so often), and you can tell it is melting while it is
not a liquid completely.
[Edited on 22-7-2006 by IrC]
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-jeffB
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multiple liquid phases, anyone?
| Quote: | Originally posted by JohnWW
Caesium is too dangerous to handle - must not be exposed to any gases or liquids other than argon and aliphatic hydrocarbons. How about gallium,
instead? (M.pt. 29ºC), or, for a lower melting point, eutectic mixtures of it with indium, bismuth, tin. Mixing it with mercury would also work, but
there would be the toxicity problem. |
A search on Google for gallium mercury yields this as the first link:
http://www.springerlink.com/index/U4614M3617W0G7Q3.pdf
You probably need institutional access or a subscription to get at the paper, but the bottom line is that mercury is only slightly soluble in gallium
(or vice-versa) -- less than 1%, until you reach a critical point at 203.5ºC.
I looked into this some time ago when I was trying to figure out the maximum number of mutually immiscible liquids you could put in a bottle at
something approaching STP. I got as far as mercury, gallium, silicone oil, fluorocarbon, water, hydrocarbon -- six phases, mutually immiscible,
although I'm not completely convinced I could keep the silicone oil from fraternizing with both the hydrocarbon and the fluorocarbon. Can
anyone suggest a seventh phase? For that matter, can anyone suggest a transparent container substance that is inert to the whole list and isn't
wetted by gallium? It's not such a fun demo if the gallium sticks to the bottle, turning it into a mirror and hiding everything else...
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Xenoid
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This company (Indium Corporation)
http://www.indium.com/products/fusiblealloys.php
makes a range of gallium/indium alloys with MPs ranging from about 7 oC. up to 30 oC.
They are marketed as mercury substitutes (for physical processes). I haven't enquired about the prices..... 
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dann2
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Hello,
Try a search for Woods metal for low melting point compositions.
They will be above room temp though
Dann2
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unionised
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-jeffB
If you saturate the water with salt then you can add acetonitrile as another phase.
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-jeffB
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| Quote: | Originally posted by unionised
-jeffB
If you saturate the water with salt then you can add acetonitrile as another phase. |
Interesting! But I fear the salt water would attack the gallium, especially in galvanic contact with the mercury. Rats.
That might be a good phase to replace the gallium outright, though -- the gallium is sticky, and the interface between the gallium and mercury would
probably be hard to see.
Is acetonitrile really immiscible with hydrocarbons/fluorocarbons/silicones? I'm getting seriously tempted to actually try this...
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