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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...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.
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?
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.
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?
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
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.