Tuesday, 5 February 2013

Super Dense Water is Awesome

A dense form of water?

As you know from reading this blog surface tension is like a trampoline.  It is like a thin coating of elastic fabric that can hold a particular force (like a child) in the vertical plane and a held by springs supporting that weight in the horizontal plane.  We still have a lot to learn about surface tension and its properties though from the Marangoni effect to what they are doing at SLAC National Accelerator Laboratory and at the Lawrence Berkley National Laboratory.  There scientists started working with dense water which remained liquid well beyond its typical freezing point.

These researchers then applied a superthin coating to the surface of a barium fluoride crystal.  Superthin means in this case no deeper than a few molecules (that is pretty thin).

What did they expect?

They expected to stimulate ice formation when they lowered the temperature below 0 C.  However, that would be boring and not worth writing about.  Even when lowering the temperature to -14.2 C the water on the surface of the barium fluoride crystal remained liquid.  Then things got a little crazy.  The molecular structure of the crystal surface transformed into a high density form in a broad temperature range.  This mimicked the density that water achieves at higher pressure.  This research took three years (three years of trying to explain to your husband or wife of how interesting surface tension is) and included experiments with synchotrons laboratory and computer simulations with Swedish collaborators (det ar jattebra!)

What does this mean though?  It gives us a better understanding of how water exhibits exotic properties under a range of conditions (said by Anders Nilsson one of the lead authors).  Water is exotic and is still the one of the only molecules known to sustain life.  Its properties, as shown in this paper published in Nature Scientific Reports, shows how scientists intense fascination with this wonderful simple molecule.  

With this information it might help scientist design materials that can 'steer the water structure and properties' like new membranes in water purification, fake rain clouds and efficient hydrogen fuel cells (I made the last two up).  These nerds from the SLAC are also exploring other unique unusual properties of water under a range of conditions from understanding the typical freezing point and the solid vs. the liquid form.  They are refuting "widely believed concepts" that the pattern of the crystal's surface, which is similar to the latticed molecular structure of ice, can greatly impact ice formation by serving as a sort of artificial template, he says.

First seen here: