A Liquid That Turns Solid When Heated 450
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."
speculation on applications? (Score:3, Interesting)
thermometers for the 21st century and beyond.
Assassins take note! (Score:4, Interesting)
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...
Missing some info here (Score:5, Interesting)
Applications? (Score:2, Interesting)
The Sci Fi angle... (Score:2, Interesting)
I'm not sure this is that new (Score:4, Interesting)
Good work but not revolutionary. (Score:3, Interesting)
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.
Space shuttle? (Score:3, Interesting)
New meaning to the term lock up (Score:3, Interesting)
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
Re:Heat shield? (Score:3, Interesting)
Useful material to have when printing out organs (Score:5, Interesting)
BTM
Re:Application: Construction of Skyscrapers (Score:2, Interesting)
Re:Missing some info here (Score:3, Interesting)
Re:Application: Construction of Skyscrapers (Score:5, Interesting)
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?
liquid bullet proof jackets anyone? (Score:4, Interesting)
Re:Cool (Score:5, Interesting)
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
Re:speculation on applications? (Score:1, Interesting)
A limited slip differential is a good place to start...if wheel pairs are turning at very different rates, the differential fluid heats up and freezes. If it gets too hot and is in danger of being damaged, it melts again.
For this to be a useful application, we need tight control over what temperature the compound exhibits the phase changes. Otherwise, it is literally, just a solution in search of a problem.
Re:Missing some info here (Score:5, Interesting)
That's in theory, of couse, since you can't hit 0 degrees Kelvin.
But assuming you mean 'near 0 Kelvin', like d00ket pointed out, things get really weird down there. Some substances don't appear to have freezing points, there is no state below 'liquid'...they just move slower and slower. And some freeze quite normally, then do another transition way down there where they move back to a liquid like substance.
The substance in the article is interesting, but not completely amazing. Various 'states of matter' are just rules of thumb.
Re:Application: Construction of Skyscrapers (Score:0, Interesting)
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?
Re:Application: Construction of Skyscrapers (Score:2, Interesting)
Re:Weird, but cool! (Score:3, Interesting)
Slashdot Egoists + science story = hilarity (Score:5, Interesting)
The process they describe IS polymerization (Score:3, Interesting)
Re:Missing some info here (Score:3, Interesting)
I could be wrong, but I think that many-body interactions can change the internal states of the atoms, which of course must be the same across the board for the condensate to form.
In a nutshell, BECs are formed by applying a magnetic field, which is essentially a 3D SHO potential (mass on a spring). The atoms are cooled by lasers, craftily 'detuned' from the resonant frequency of the atoms, so that, due to the Doppler effect, atoms approaching the laser experience a retarding force, while atoms receding from the laser experience very little force. In this manner the gas sample can be cooled to ~1 microKelvin (?), which is still far too warm for condensation to occur.
The magnetic field is then manipulated to form a 'cup' which holds the atoms. The walls of the 'cup' are gently rolled back, so that the most energetic of the atoms 'boil off' the top, taking excess energy & entropy with them (evaporative cooling), and the remaining atoms rethermalize at a lower temperature.
Once a significant number of atoms fall into the ground state of the SHO, the rest quickly follow, as the probability of scattering into a given state greatly increases with the number of atoms in that state. (this is entirely analogous to photons in a laser all precipitating into the same state, for the same reasons, forming a coherent beam. And it only occurs for atoms which are bosonic, ie those for which #p + #n + #e = even)
Re:Missing some info here (Score:3, Interesting)
I know, it's a trick. The fermionic atoms pair up [colorado.edu]. Weird trick, I don't really get it. (How are they overlapping enough do that in the first place? Damn quantum mechanics.)
So, more technically, it only occurs for entities which are bosonic.
But that way leads to madness and people walking though walls after removing a few atoms from their body and the wall.
Re:Missing some info here (Score:2, Interesting)
Thanks for the cool link! They overlap because the de Broglie wavelength of the particle is inversely proportional to its momentum, and the particle can't be located to any more accuracy than its wavelength, hence at low temperatures the atoms are spread all over the place. This is also how the BCS theory explains superconductivity (pairing of electrons in that case), but I guess you probably know that
Also of relevant (to this thread, not the story) interest is that during the formation of a neutron star, there is a period during which the iron atoms of the stellar core pair up and hence exhibit superfluid behaviour, before their electrons are crushed into their nuclei.(not that I've ever met a forming neutron star, of course
Re:Application: Construction of Skyscrapers (Score:1, Interesting)
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!
Re:Application: Construction of Skyscrapers (Score:3, Interesting)
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.
Re:Assassins take note! (Score:3, Interesting)
The human body is a toasty 37 degree celsius (98.6 degrees fahrenheit). To take it to 47 degrees (116 degrees) would likely kill the person long before the hardening of the substance would.
Never mind the 75 (167) degrees...
Methinks that this might have some value as reinforcement for ceramic moulds.
Or... perhaps a form of cooking spray that would be guaranteed non-stick. Spray the liquid into the pan, bring the heat up until it's solid, cook until food is done, remove food, and let pan cool. Wash substance off and repeat process.