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A Liquid That Turns Solid When Heated
Roland Piquepaille writes "There are some sure things in life, such as death and taxes. When you are heating a solid, you expect it will melt and when you're boiling water, you're pretty certain that it will turn into vapor. But what about a liquid that becomes solid when it's heated? Of course, it has already been done, for example in the chemical process of polymerization. But now, PhysicsWeb writes that a team of French physicists has discovered a law-breaking liquid that defies the rules. When you heat it between 45 and 75C, it becomes solid. But the process is fully reversible, and this is a world's premiere. When you decrease the temperature, this solid melts and turns again into a liquid. I'm not sure of the implications of such a phenomenon, but it's fascinating. Read more for essential details."
so what could the application of such a material be? a new breed of thermometers are on their way, i guarantee it.
thermometers for the 21st century and beyond.
So...if you were to put this in someone's bloodstream with the right concentration, you could cause it to solidify once it reached standard body temperature...
You know you've lost it when you begin signing physical documents with =^_^=
It's a solid at those temperatures, what is it at higher temps? Liquid again? Does it have two melting points? At what temp does it vaporize? Does it freeze at some point below the normal low-end melting point? At 0 degrees Kelvin, it's definitely a solid, somewhere above that, a liquid, then a solid again, then a liquid again, then a vapor? Maybe.
Get ready for the soon to be classic -cyclodextrine in the oilpan trick.
*Splort*
Isn't this how "The Andromeda Strain" did it's dastardly work? Turning the blood into a solid crystaline polymer?
I remember either Porsche or Volkswagen having a limited slip clutch that consisted of two perforated disks set next to each other in a container of special goo. If the wheels slipped it caused the disks to rotate at different speeds and the friction caused enough heat to turn the goo solid. I can't remember why they quit using it but it was more than a few years ago. I think it was going into their 4 wheel drive race cars. Just a memory though I got no hard data. Anyone know more about this?
Reverse melting has been known for a long time.
People have been studying vortex systems that
do that. This is only new because it's a chemical
compound (rather than say electrons) that does this.
No physics breakthrough here. Maybe chemical
engineering breakthrough but that's it.
I wonder if it would be possible to change the temperature at which it re-liquifies, and if it becomes harder or more dense at higher temperatures. Seems like if that were the case, it would make for a good tiling material for the skin of a space shuttle
I sure hope it's non-conductive so I can put it as a coolant in my computer. Computer gets too hot, it turns solid and the computer "locks up". Ha!
Seriously though, if this stuff interacts well with other substances (i.e. doesn't explode, melt, send it to another dimension) then it could feasibly have applications where it would solidify around objects once they got too hot, thereby stopping their motion. And since the article says you can adjust the solidifying (freezing?) point based on its concentration, it could be tailor-made for different devices. This probably won't happen though because I'm guessing this stuff is probably expensive to make and does who-knows-what to human tissue
i hotdog.
The interesting thing about that application is that the shield could reform when things cool down. If it were an ablative shield (takes damage), then you could potentially have it fix itself between uses.
This article describes a similar material that is liquid below 20 C and solid above 32 C. Medical researchers hope to use it if they are able to perfect 3D printers that generate organs by spraying cells onto a substrate. The gel is used to reserve open spaces for blood vessels. Once the organ has been formed they cool it and the solid turns to liquid and runs out.
BTM
That was the turning point of my life--I went from negative zero to positive zero.
You talk as if fire is a real threat to reinforced steel skyscrapers. Prior to 9/11 there had never been a case of fire causing a skyscraper collapse. In fact, there was not even a real investigation proving that fire caused the 9/11 collapse; the steel was immediately shipped to Asia for scrap metal. So, since fire is not a big threat to skyscrapers why waste money trying to incorporate a new, unproven and likely expensive technology into steel skyscraper construction?
First, the World Trade Center collapsed because jet fuel burns extremely hot. The WTC design was actually far stronger than most other skyscrapers standing today. Notice that the building survived the initial impact of a plane, and that it wasn't until later, when the intense heat of the burning fuel had time to weaken the steel support structure that it collapsed. A normal building fire would not have threatened the structural integrity of the WTC because there was nothing in the WTC that was hot enough to melt the beams, until the plane, full of fuel, arrived.
Second, I didn't notice in the article whether the volume of the material expands or contracts when it turns solid. If the hollow beam is partly filled with liquid (because the liquid expands when frozen) then there isn't necessarily enough contact between the liquid and the burning sections of the building to protect the upper portions of the beam. The beam will conduct some of the heat to the liquid, but depending on where the fire occurs in relation to the beam, the top of the liquid might freeze first, leaving the upper portion of the beam hollow. If the liquid contracts when frozen, you end up with a partly filled beam, which isn't necessarily stronger than a beam with nothing in it.
This leads to the third point, that nothing is mentioned about the structural properties of the liquid when frozen. Steel behaves extremely well under tension, and concrete under pressure. Thus, they complement each other quite well (which is why we make buildings out of them). Would the liquid make a better replacement for the steel, or the concrete? And would it perform equally well when the building is not on fire? Has having liquid-filled cavities in the building strengthened or weakened the structure, for the large majority of the time?
Finally, does the cost of using a material like this justify it? It's new, it probably costs more than steel to use in a building. Wouldn't redundant support structures be more reasonable? Or, using a design like the WTC, which I noted only failed from the heat of burning jet fuel?
I remember reading somewhere about making a bullet proof suit for soldiers where the suit was in fact hollow and filled with a gel containing nanoparticles. This thing might help us make more efficient ones: when the bullet hits the gel, the pressure is going to make it increase in heat, isn't it? So as the bullet tries to penetrate, it's going to get harder and harder... thus absorbing a HUGE amount of energy. Once the bullet is fully stopped, the pressure disappears, the temperature goes back down to normal and you have a liquid armor again. One problem is keeping the liquid from spilling out of the holes the bullets make... But I'm quite confident that can be overcome with some brilliant imagination. Of course, the real problem is how breakable is the solid formed? Because if the bullet goes straight through the hard material, then there's not point. But I think that'd be one use of this...
---- I am certain of only one thing : I know nothing else.
Check out http://www.solgel.com/educational/glossary.htm/ and http://www.chemat.com/html/solgel.html/
Its basically a more refined process of distilling out a liquid from a solution, and getting a solid out. However this new solid has chemical properties of both parts of whatever was in the solution. It allows for things like low-temperature glassmaking.
Literally a "sol-gel" is just a solid that still has some of the properties of a liquid/fluid such as flowing and free atomic relocation, but is much closer to a solid then a traditional fluid. This however does not make it a "jelly" or a "gel" its chemically, as well as physically distinct.
Medevo
Hi Mr. Expert,
Why did WTC #7 collapse? No jet fuel, it was pretty far away from the towers.
Could it be that we've been lied to? Could we really have the only case of steel buildings ever collapsed by fire?
William Langewiesche in his _American Ground_ set of Atlantic Magazine articles (Aug-Oct 2002) writes that it wasn't so much the jet fuel that caused the collapse of the towers, but all the paper inside them. It's been a while since I've read the articles, so I don't remember all the particulars, but dig them up if you are interested in the scenario.
It was a joke. Perhaps you should stop working of your vocabulary and start working on your sense of humor. ;->
Every one at slashdot thinks they understand science because they think of themselves as geeks. I say it is not being a geek that makes you a scientist, but being a scientist makes you a geek. This story is a perfect example. Some material does something that we would not expect based upon our own observational experience, but since we "know science" it must violate all of our accepted scientific ideas. Its really funny if you don't take it serious. Seriously it must show that our educational system has doen such a poor job of explaining the basics of the scientific process and/or that we'd rather make fools of ourselves than admit that we don't know everything.
Well.. maybe. Or Maybe not. But Definitely not sort of.
This is not novel. This polymer just happens to form weak bonds, as opposed to disulfide, vinyl, ester or other types of strong bonds typically associated with polymers. That's the neat part - they're mostly reversible.
There exists no way of exchanging information without making judgments. --Bene Gesserit Axiom
Professionally demolished buildings are IMPLODED so that the debris falls into the footprint of the building.
The WTC buildings COLLAPSED, which spilled immense quantities of debris around the buildings, killing firefighters, police officers, etc. and crushing equipment.
Any competent structural engineer can tell you why the building fell down instead of falling over (hint: the metal isn't any stronger, it's just arranged in a very particular structure). Also, at the point of failure, you had 1/3 to 1/2 of the building falling at least 1 floor height before it stuck an undamaged point of the building. Some basic physics calculations will show why a building can't withstand a floor (at least) effectively disappearing.
BTW: There was a great analysis of the WTC collapse on Nova (one of those pesky science programs on PBS) that presented the views of a number of structural engineers, including the engineer that designed the towers. Strangely, they've bought into the "big lie" as well. The mind control people are coming for you next. Run! Hide!
In a word, NO.
At best it proves how little we understand that law, but there's nothing to say the entropy wasn't balanced by the energy transfer involved(all physical condensations, straight from gas to solid would be a lot worse from a disorder aspect, without factoring the energy involved), and it's quite likely the math will bear this out(but I'm too lazy to do this math).
It also shows how an instinctive understanding of physic laws can lead to misunderstanding those laws. I'm sure someone tried to invalidate a few physics laws when we discovered water actually increased volume when heated from 4 degrees celsius to 0 degrees celsius too. Turned out the law was perfectly fine, as long as you interpreted the whole thing, with the phase change graphs and triple-points, and not just the instinctive understanding: heat it and it expands, then becomes liquid, then expands again and becomes gas.
Trying a simplification of the law, finding it doesn't work, doesn't necessarily mean the law isn't good, it might just be a bad simplification, after all.