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Thin Water Acts Like a Solid
Roland Piquepaille writes "What happens when you compress water in a nano-sized space? According to Georgia Tech physicists, water starts to behave like a solid. "The confined water film behaves like a solid in the vertical direction by forming layers parallel to the confining surface, while maintaining it's liquidity in the horizontal direction where it can flow out," said one of the researchers. "Water is a wonderful lubricant, but it flows too easily for many applications. At the one nanometer scale, water is a viscous fluid and could be a much better lubricant," added another one."
Well, based on poor results getting it on in a swimmin pool, I can verify that water is a lousy lubricant at normal scale!
But cold water also acts like a solid at times.
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That's for gasses.... The article discusses... water as a liquid, acting as a solid... so no, Pressure (Pa) * Volume (m^3) != # moles * 8.31* T (K) here.
appleguru.org
...it's called prison lube.
There's actually alot of evidence in the literature suggesting that water forms a "structured layer" on hydrophillic (water-compatible) surfaces, and around hydrophillic objects dispersed in water. For instance the mobility of water that structures around proteins has been described in the literature as "ice-like." These measurements are typically based on the density of the water or using things like conductivity to infer mobility.
So the notion of water forming solid-like structures near surfaces is not entirely new. However, direct mechanical measurements of the mobility/viscosity of those last few atomic layers of water are not easy, so this paper certainly adds a valuable contribution to the field.
The actual scientific paper in question can be found here: http://dx.doi.org/10.1103/PhysRevB.75.115415
Of course, PV=nRT is the ideal gas law, but there is a similar relationship for monolayers -(pi)A = nRT - a 2D analog of the ideal gas law for a layer one molecule thick which is often a liquid on another liquid or on a solid. This is when the monolayer is sparse enough that it acts like a gas, even though it may be comprised of molecules which are liquid at that temperature. Pi in the formula is the film pressure and A is the area. This is not really related to the phenomena described in TFA.
...the future crusty old bastards are already drinking the Kool-Aid.
From what I can tell, F@H touched on this a while ago. I was reading the PS3 F@H articles, browsing through the "what good does F@H do?" and the "F@H is just a feel-good project" comments and looking at the results page when I stumbled across the above PDF and thought "Hey, that looks like something slashdot just reported on."
I can't believe the popular notions of water in a nano-sized channel are false! Soon they'll be saying that the attorney general acts like a solid under pressure in a nano-sized tube. If we can't believe the popular notions of nano-tube water behavior, what can we believe? My life is a lie!
This is a hydrophilic channel. In a hydrophobic channel, the vapor phase is more stable than the liquid, so you get "cavitation" or "dewetting", as you approach the walls of the channel closer and closer, at some point all the water gets pushed out of the channel and the walls get pushed together.
The phenomenon is well understood in the hydrophobic case, both experimentally and in simulations. This experiment is new, up till now they couldn't get down to such small separations, but they are overstating the case when they claim that this is a complete surprise... as another poster said, many many simulation studies have suggested a structuring of water near hydrophilic surfaces.
Another neat thing happens when you have one wall hydrophobic and one wall hydrophilic. This has been dubbed a "Janus interface" after the two-faced Roman god, and there's a lot of interest in them.
Oh my god I can't believe I actually read that as "I Am Not A Scientist But I Play One On TV". . . .
Be back soon guys . . . I'm gonna go outside for a while.
I think he has hi's possessives right.
rj
Turns out some guy in the middle east figured this out a couple of millennia ago. They called him the Nazarene or something; apparently even did some tricks where he walked on the stuff. Once again, slashdot is just recycling old news.