Israeli Scientists Freeze Water By Warming It 165
ccktech writes "As reported by NPR and Chemistry world, the journal Science has a paper by David Ehre, Etay Lavert, Meir Lahav, and Igor Lubomirsky [note: abstract online; payment required to read the full paper] of Israel's Weizmann Institute, who have figured out a way to freeze pure water by warming it up. The trick is that pure water has different freezing points depending on the electrical charge of the surface it resides on. They found out that a negatively charged surface causes water to freeze at a lower temperature than a positively charged surface. By putting water on the pyroelectric material Lithium Tantalate, which has a negative charge when cooler but a positive change when warmer; water would remain a liquid down to -17 degrees C., and then freeze when the substrate and water were warmed up and the charge changed to positive, where water freezes at -7 degrees C."
I could be stupid (Score:5, Insightful)
But I was expecting something along the lines of "Researchers manage to make water freeze at greater than 0C," instead of "Researchers manage to make water freeze below normal freezing temperature."
Haven't they ever heard of salt? Or Anti-freeze?
Re:I could be stupid (Score:5, Interesting)
I thought pure water doesn't go solid, not until an impurity starts crystal formation that turns the water into a solid?
Re:I could be stupid (Score:5, Informative)
I thought pure water doesn't go solid, not until an impurity starts crystal formation that turns the water into a solid?
In many cases, the surface of the container has defects which can play that role.
Re:I could be stupid (Score:5, Interesting)
I thought pure water doesn't go solid, not until an impurity starts crystal formation that turns the water into a solid?
This comment seems really unintuitive so I looked around a little. Ice [wikipedia.org] can actually form entirely without crystallization, by cooling it to ~137 C in a matter of milliseconds. The article also mentions that "pure water, in the absence of any nucleating surface, can remain in a supercooled liquid state down to temperatures as low as -40C". I guess that means that pure water will begin crystallizing at this temperature anyway.
Re:I could be stupid (Score:5, Insightful)
Exactly, this is well known, and is the difference between homogeneous nucleation caused by the massive undercooling providing the energy to nucleate ice spontaneously versus heterogeneous nucleation which requires much less free energy and occurs dependent on surfaces.
It is not scientifically interesting that they warmed it to get it to freeze, that's just a comparison of freezing points... it's interesting that the charge of the surface modified the freezing/nucleation point. Frankly, I am amazed that this was published in Science; it seems like worthwhile research, but for a journal more like, say... applied physics letters or a more specific interest journal. Kudos to the researchers for managing to spin it as a general-interest paper when it is in fact a fairly simple observation of an obscure phenomena.
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I realize that I'm ignoring lots of physical detail, but like others above I remain unimpressed by the ability to freeze water at 137 degrees below its freezing point. It won't help my radiator on a cold day, unfreeze my pipes or the walk outside, as those environments don't have the purity and perfection required to get away with this.
Can someone offer an example of a useful application of the ability to freeze pure water at -137 degrees? Someone must have taken advantage of this property to do something
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So you are saying that even in a "liquid" state, water has crystals that have formed? Fascinating. It truly amazes me how little we know about water and how we keep discovering new things about it. There are a lot of quacky people that think the homeopathic effect works, but if you ask me, it really sounds like pseudo-science. The placebo effect may actually be more powerful, so what does that say?
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Defects in the container can help it to freeze. It can also help to prevent superheated water in the microwave. I've come close to being burned by this effect.
I remember one time when younger smashing the ice in a puddle with my foot while running and the water underneath making a cracking sound after a second. It was odd enough for me to stop and look. It had frozen solid in an instant. It had a odd pattern to it but I was more interested in getting to some place warm so I didn't really stay and examine it
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I had something like that happen to me. Most people I mention this to think I am bullshitting them. About 20 years ago I had put a filled plastic bottle of water in the freezer to take with me on a hike the next day. The next morning I opened the freezer and pulled out the water bottle. To my surprise, it was clear as glass. I was a little confused wondering if this was my bottle when my thumb made an indentation in the plastic. Within about
More to the point: (Score:3)
In other words:
The crystallization has to start somewhere. Imperfections in the surface or impurities supply this. If you have very pure water and a "perfect" container, the lack of a starting point for crystallization can delay the phase transition by quite a bit.
(Then you get YouTube videos showing flash freezing of water bottles!/i))
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Re:I could be stupid (Score:5, Informative)
Salt and anti-freeze just have typical freezing-point depression; there's no way to use them to produce a situation where water that is a stable liquid at one temperature will turn solid if you increase the temperature. The situation in this experiment is that water that's liquid at -17 C will freeze as you head it up towards -7 C.
Re:I could be stupid (Score:4, Interesting)
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So that's why my car gets covered in an inch-thick sheet of perfectly clear ice. That's always bothered me, thanks!
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You are correct about the humidity in the air, and how the most obvious effect of that (at least to those of us in colder climes) is the formation of black ice on the road... but I think the interesting part of this experiment isn't that they were able to cause the water to freeze by raising the temperature from -17'C to -7'C, it's how they were able to do it. Namely, that the freezing point of water changed based on the electric charge of the surface the water is on. Shouldn't really come as a surprise, as
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Amen. This has nothing to do with changing the temperature of the water and everything to do with changing the charge on the container (which happens to be a function of temperature). It would be interesting to replicate this experiment on a piezoelectric rather than pyroelectric medium and force the water to phase change by deflecting one surface of the container a bit.
Re:I could be stupid (Score:5, Informative)
Re:I could be stupid (Score:4, Interesting)
In this supercooled water experiment [youtube.com] video, notice that the supercooled water freezes after the bottle is tapped. So energy is put into it, meaning that it is warmed up slightly. Isn't this also reversing the cold-warm solid-liquid order?
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By "cheating" I meant it's cheating if the game you are playing is called "try to freeze water by warming it up." They just didn't do that.
Except for the sensationalist headline that implied that they did, and won.
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Doesn't look very much like supercooled water. Atleast two details are missing. First, if it was supercooled, I would assume condensed water droplets on the surface of the bottle, or frost. Also, if it actually was frozen water, the bottle should expand as the ice takes up more volume than liquid water. It most likely is sodium acetate dissolved into water.
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Yeah, and if you pull a certain amount of vacuum on it, you can get water to do all of boil, liquefy and freeze [wikipedia.org] at the same temperature. This is even without applying mechanical energy or kinky fields (electrostatic or magnetic) to coerce its behavior.
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Making water freeze at >0'C is actually very easy. Just reduce the pressure [wikipedia.org]
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That's easy, all you need is a vacuum.
It'll boil at the same time, but that can't be helped...
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This could lead to a way to make ice cream without salt. They've managed to lower the freezing point of water without having to put any chemicals in the actual water itself.
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And a huge hurrdurr on my part, perhaps this could replace antifreeze in some way in the future through some sort of complex radiator system. -1 toxic chemical inside a car.
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I would think the only interesting thing would be that this is (presumably) at standard pressure.
Applications? (Score:4)
Re:Applications? (Score:4, Interesting)
Apply that weird surface to generate the weird behaviour, and use it to power a Stirling engine.
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are there some cool real-world applications I'm not thinking of?
Seeing that the water was bellow freezing in both cases, you can bet on some cool application!
Re:Applications? (Score:5, Funny)
A pyroelectric lithium tantalate ice cube tray? In animal shapes?
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but are there some cool real-world applications I'm not thinking of?
Cheaper cooling solutions for super computers than stuff like Flourinert, of course this could also makes for dirt-cheap AC units, refrigerators and so on.
Just think...no more bulky compressors for cooling.
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It's been quite a while since I've thought about "extreme" computer cooling solutions, but I thought Fluorinert was just a non-conductive liquid that otherwise was quite water-like. I used good old dollar-a-gallon distilled water in my old watercooling setup and that worked perfectly well.
Of course skimming Wikipedia tells me that you can get some with very low boiling points, but you wouldn't usually use evaporative cooling for computers (I've seen it done, but it's impractical at best; downright dangerou
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In various parts of the world where you have unreliable power and a need for cooling, the ability to cool without massive draws is a huge benefit especially in the medical community. The other option is to use clay, but that can get messy after abit.
Progress (Score:5, Funny)
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How so? Water usually freezes around 0 C, they managed to make it freeze at -7 C. That's the wrong direction if you are trying to figure out how to freeze hell.
Overflow (Score:3, Funny)
By reading the title only, I thought the overflow-bug of water was finally found.
Anti-freeze (Score:1)
I wonder if it's feasible to coat this material on the inside of water pipes, to prevent them freezing in winter?
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Sure, but do you really want your water pipes freezing in the summer instead?
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Tantalum is non-toxic, but you know it doesn't really work like that. Sodium is explosive; chlorine is toxic; sodium chloride is tasty.
Still, as you say, lithium tantalate is going to be far too expensive for coating pipes.
Dowsing (Score:1, Funny)
An Australian from Mitta Mitta who failed a dowsing test claimed that he only failed because the water was "electrically charged wrong".
http://video.google.com/videoplay?docid=4694530584288972114
Re:Dowsing (Score:5, Funny)
A dowser was working Down Under
when his failure caused him to ponder
"the charge on me watta
was more than it oughta.
So I couldn't tell lightning from thunder."
Israeli Scientists (Score:5, Interesting)
Re:Israeli Scientists (Score:5, Funny)
Obviously Chemists are more nationalistic than Physicists...
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Re:Israeli Scientists (Score:5, Informative)
Slashdot headlines seem to do it now and then:
Canadian Scientists Regrow Teeth [slashdot.org]
French Scientists Link Higher BMI with Lower IQ [slashdot.org]
British Scientists Reverse Casimir Effect [slashdot.org]
German Physicists Claim Speed of Light Broken [slashdot.org]
Japanese Scientists Claim To Reconstruct Images From Brain Data [slashdot.org]
Italian Scientists Put Robot Spiders In Your Colon [slashdot.org]
etc.
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I don't find it particularly disturbing. I was pointing out the examples for the opposite reason--- to suggest that "[Nationality] Scientists" is not a particularly unusual phrase, contrary to the claims of the poster I was replying to.
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Maybe it's confirmation bias, but I've seen this over and over in "Israeli X does Y" articles on slashdot (eg. Intel engineers coming out with a cool new chip). I've yet to see the complaint launched at Norwegians.
Your hypothetical situation isn't parallel precisely because it didn't happen. If it did happen, then you have a point.
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Just wanted to point out that rubbish such as organ harvesting isn't particularly new - unless you count switching from Christian kids to Palestinian Arabs as some kind of creativity.
People, after all, believe what they want to believe. 700 years ago it was a little harder - a pastor had to work hard to convince his followers that their Jew neighbors are "organ harvesting vile psychopaths". Today it's enough to show a photo of a bunch of cow hearts and everyone goes berserk.
Cow hearts? Oh, stop it. I'm not talking about 700 year-old religious propaganda aimed at the poor, long-suffering Jews who must never be evaluated in the same light as any other war criminal, (because they're special!) I'm talking about Israel's chief pathologist being investigated for organ harvesting. [israelnationalnews.com] And you know it.
As a side note - who is exactly this "government" you're talking about? I was sure it is democratically elected. And replaced every 2.5 years in average, by the way. So - unless everyone here is a psychopath (a wonderful word, by the way), eventually we will run out of psychopathic governments. Shame. Where will I get my extra eye-balls then.
Well, THAT was the lamest piece of 'logic' I've heard today. Congratulations. Are you telling me that "Democracy" prevents corruption? I think the grand experiment in America has pro
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You really need to learn how to follow a comment thread...
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Wait until you see tommorow's story: American Slashdot Editors Add Superfluous Words When The Title is too Small.
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Nothing new I have noticed this with my beer ;-)) (Score:5, Interesting)
When I put a beer in the freezer too long but not that long, when I take it out of the freezer, I can see it is pretty 100% liquid inside the bottle. Now, taking it out of the freezer makes it warmer and opening it even warmer due to air circulation inside the bottle.
Well, when I open it, it turns to ice so I make my beer freeze by making it warmer so nothing new here ;--))))
Very seriously, I swear this is true but I understand it could be due to other factors that the ones described in TFA like pressure inside the bottle but I thought it would interesting to mention anyway.
Haven't anybody else seen their beer freeze in their hand while opening it just after it has been in the freezer although it was in a liquid state when they actually took it out of the freezer ?
Re:Nothing new I have noticed this with my beer ;- (Score:4, Informative)
That's an old bar trick. It has to do with the co2 being released on pressure change. Nothing like the science these folks have described.
Ah, I see you are an american (Score:5, Funny)
You clearly must be an American, since you compare beer to water. Over here in the old world, we know there is a difference by the taste for one.
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My first thought on reading the GP was "will this work with bottled real ale, or is it just hops-flavoured soda water like Budweiser?"
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Bud is very much an American lager, but you are criticizing it poorly; see, it isn't particularly hoppy, and it has a rather high alcohol content (for a mass market beer).
Contrary to what kids think (Score:2)
Re:Contrary to what kids think (Score:4, Informative)
I think he was referring to the fact that it tastes like fizzy water with beer-like flavour, not the alcohol content. And Budweiser tastes pretty darned watery, even compared against other beers of the same type. Ales usually have a heavier taste to them, so it's not really fair to compare Budweiser against something like Guiness or Caledonian in terms of flavour. It is, however, fair to compare it against a good lager like Pilsner Urquell. Even when you compare it against a shitty lager, like Labatt Blue (which is also a pilsner, like Budweiser), Budweiser comes out on the bottom.
(and no, I'm not saying that Canadian beer sucks, just that some of the most popular Canadian beers suck. Namely, Labatt and Molson. If you want a good Canadian beer, try something like Steam Whistle, or Wellington. We don't export the good stuff. Similarly, I think the Australians are smart enough to export the shitty beers and keep the good stuff for themselves, as are the Dutch... think about that when you order a Fosters or a Heineken.)
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My state used to have some weird laws carried over from those days. They have changed some
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The fact is that most (but by no means all) mass-produced beers in stores in my state are still in the 3%+ range, although no law requires them to be. I do not know why that is; I admit that I simply assumed that those mass-produced beers basically just distributed beer of those percentages.
I admit that there is something of a puzzle here. But I assure you that it is not
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Not only is it not particularly hoppy, it has a pretty significant rice content. If anything, bud is hop-flavored rice alcohol. This being said, it's still my favorite mass market beer.
Yes, we live in a cultural backwater as far as beer is concerned. In Mexico the cheap regular beer is some of the best on the planet.
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Yes, but it's due to the pressure changes and release of dissolved CO2. :-)
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When you open it COs is released this causes the pressure to fall.
pV = nRT
So you did in fact cool it by opening it.
You could also supercool it I guess and shaking it a little when taking it out causes it to crystallize - but I'm having doubts about beer and beer bottles being pure enough to not crystallize out in the first place.
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Sure, I hinted about this in my post...
But you still just gave me a great idea: I will design a beer based air conditioner ( air cooler ) and sell it/publish it on sites similar to engadget ;-)))
Put in 4 cases of 24 and have some mechanism opening them one by one coupled with a fan and I am done ;-)
First on my list: Buy 4 cases of 24...
half an hour later:
Done...
one hour later:
Second on the list: Funny, I don't remember now...
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I've also seen this happen with regularity - at work we sometimes crack a beer after hours, my boss likes to keep his cube fridge hell-frozen-overishly cold. So perfectly liquid beers (can or bottle) from the top shelf often freeze within 20 seconds after opening. He swears by the belief that giving the can a good hard squeeze for several seconds prior to opening reduces the chance of it freezing, but nobody has yet come up with a believable theory as to why that would be. Guesses so far are that the applyi
That's nothing. (Score:5, Funny)
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True, but He never published the details of how He did it.
So that's Frozone's trick! (Score:3, Interesting)
He must be negatively charged (thus keeping water a liquid on or in him) and then the moment he "releases" it, it freezes!
Could there be some sort of industrial application for this, like ice-making where you have a jet of "liquid" water (because it is kept in a negatively charged apparatus) but upon contact with something, loses its charge and freezes? How about rapid construction of ice sculptures? Just like spray on concrete.
I even seem to remember someone in WWII proposing making giant pontoons/floating islands out of ice and hay.
How about in Antarctica/on Mars using it for rapid construction of ice domes? Once it solidifies it won't melt.
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I dunno about Antarctica but I think sublimation [wikipedia.org] would be a problem on Mars.
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That's why you apply a "top coat" of some sort of plastic to the ice once formed. Of course, all that ice sculpture does is protect one from an environment that is very cold but not very conductive and so easily protected against. It also would do nothing to maintain pressure inside the "bubble". Probably easier to just use plastic in the first place...
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There has been quite a bit of work put into different 'icecretes', as a matter of fact. Here are a few examples, although I'm sure there's more that I'm not even aware of:
http://www.globalsecurity.org/military/library/policy/army/fm/31-70/Ch6.htm [globalsecurity.org]
Skip down to para 6-8.c and 6-10.b
http://en.wikipedia.org/wiki/Pykrete [wikipedia.org] and http://en.wikipedia.org/wiki/Project_Habakkuk [wikipedia.org]
http://pisces.hilo.hawaii.edu/documents/VT-NIA-PISCESFinalReport.pdf [hawaii.edu]
A *very* interesting paper on using lunar regolith icecrete for construction (
How? (Score:2)
This is going to make a better Martini how, exactly?
This is cool... (Score:1)
Opposite still working? (Score:2)
In any direction, changing state (or prevent that change) not using plain heat, but just charging electrically could make some applications more energy efficient.
big deal (Score:2)
Supercooled water will freeze with just about any trigger. The precise mechanism of this is kind of neat, but as an effect, it's not terribly surprising.
Are they calling it Ice-Nine? (Score:3, Funny)
Hmm, water ice that is stable at a higher temperature than liquid water? Can anyone say ice-9?
Whut? (Score:4, Insightful)
It sounds like it freezes due to the change in charge, not because the water warms up. It's freezing in *spite* of the water warming. It's like they are just chasing the freezing point around.
You get the same effect when opening a highly chilled bottle of soda. It starts to freeze due to the release of carbonation, although the pressure change might come into play as well.
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It sounds like it freezes due to the change in charge, not because the water warms up.
But when the water warms up, that causes the charge on the surface to change, thereby causing the water to freeze; so the water warming up, and it freezing, are causally linked. It seems more like a neat trick than anything else, but "freeze water by warming it" is a more-or-less accurate summary of what's happening.
Heat of melting/fusion (Score:2)
So, does water absorb/release 334 kJ/kg when it thaws/freezes due to this change in charge? If so, we may have some interesting applications in the area of refrigeration, heat engines, etc.
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No, it's more like the realization that Canada is south of Detroit [google.com].
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They are all taking lessons from KDawson?