Slashdot Mirror
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.
The society for a thought-free internet welcomes you.
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.
Well, you're partially right. The liquid water on frozen water is indeed very slippery. This is what allows ice skaters to skate, the blade glides along a thin film of liquid water. Frozen water on its own, however is not that slick.
If it is hydrophobic, what we see may actually be the effect of lost entropy due to rearrangement of water molecules, rather than compression.
There is a spark in every single flame bait point.
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."
How about just outside the Gatlinburg museum's entrance, visitors can see a 5-ton solid granite ball floating and spinning on 1/264 of an inch of pressurized water. Visitors may put their hands on the 4-foot diameter ball and spin it in another direction. Or the Merchant Family Memorial (Ripley's Believe It or Not Ball).
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!
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.
Density and viscosity are the primary factors when choosing a lubricant. Water happens to have a pretty low viscosity. The point of article is that the effective viscosity increases by several orders of magnitude in truely thin sheets and takes an ordered form like a solid in one direction but not the others, not that thicker films of water can be used as a lubricant. In fact, they found that as the gap gets down to a nanometer, it becomes a less effective lubricant.
I started typing this and thought to myself, "Something about the way that submission is written and how it misses the point of the article smells of Roland Piquepaille."
I wasn't at all surprised when I went back and checked the author to see his name and standard question-link-quote writing format.
Now I'm curious because the pressure they apply seems to be of interest here. I'm curious if 3 dimensional order appears under high isotropic pressures. If so, I'd expect this to be possible in larger volumes with sufficient pressure, and I wouldn't be at all surprised if the viscosity increased, too.
sounds like Ice 9 to me
*
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.