28 Sep 07
1 edit
Originally posted by FabianFnasI use DI water in our cleanroom, we have a facility that makes DI water from street water, a very large system of filters, Reverse Osmosis pumped filters and active ionization filters, the ultimate restistance of DI (De-ionized water) is about 18 megohms/sq. Cm, the standard measure for DI water.
We try with one molecule of water. Is this ice? No, we can all agree that there is no meaning talking about one molecule of ice.
The fun starts when we try two molecules of water to see if it can be considered as ice.
How do we attach the two molecules together?
Where do we have them to begin with? In some ind of vacuum not to be disturbed by othe really interesting. It' will be a future topic to discuss over a beer with some good friends.
That is water that has extremely little in it besides H20, no H+, O+, or much of anything else besides H20. So you have these mickey mouse ear shaped molecules, polarized because of the angle of the dangle and then as it starts to freeze, they must somehow pop out a bit to lower its density so ice can float. So I am thinking there has to be enough molecules in a 3 dimensional grouping for this state to appear. How many though, I don't know. I would bet money on it being a lot smaller a number of molecules than the 10^6 mentioned.
Found this article online from 1999 about the subject of the structure of ice, very informative, it says, among many other things, that there were 10,000 scientific papers written about ice in that year alone. So it's a big subject for sure. However it did not address my question of the minimum amount of water molecules needed for it to be called ice.
http://www.tms.org/pubs/journals/JOM/9902/Schulson-9902.html
28 Sep 07
Originally posted by sonhouseI didn't mention anything about O+. I said that water always is a blend of H2O, and a fraction of H+ and OH-. It sometimes happen that H2O brakes up and reconstructed back into H2O. This has nothing to do with purity. That's how water behaves. Quite natural.
That is water that has extremely little in it besides H20, no H+, O+, or much of anything else besides H20.
28 Sep 07
Originally posted by sonhouseHow can you distil the H+ (shouldnt that be H3O+ ??) and OH- out of water? Isnt that a natural phenomenon?
I use DI water in our cleanroom, we have a facility that makes DI water from street water, a very large system of filters, Reverse Osmosis pumped filters and active ionization filters, the ultimate restistance of DI (De-ionized water) is about 18 megohms/sq. Cm, the standard measure for DI water.
That is water that has extremely little in it besides H20, n ...[text shortened]... needed for it to be called ice.
http://www.tms.org/pubs/journals/JOM/9902/Schulson-9902.html
28 Sep 07
Originally posted by FabianFnas"Water should be scripted H2O, H+, and OH- mixed. This means that a water molecule may be splitted in two ions"
We try with one molecule of water. Is this ice? No, we can all agree that there is no meaning talking about one molecule of ice.
The fun starts when we try two molecules of water to see if it can be considered as ice.
How do we attach the two molecules together?
Where do we have them to begin with? In some ind of vacuum not to be disturbed by othe ...[text shortened]... really interesting. It' will be a future topic to discuss over a beer with some good friends.
Fabian- I know that is true in the liquid state but is it true as a gas (how?!?!) or a solid (possible I guess .. does ice consist partially of ionised lattice such as salt?? ) and as my previous post doesnt the +ve ions in water actually consist of H3O+ ions?
28 Sep 07
1 edit
Originally posted by wolfgang59The piece I posted mentions a salt-water ice that can be up to 7.5% NaCl. The piece says there are something like 10 or more kinds of ice.
"Water should be scripted H2O, H+, and OH- mixed. This means that a water molecule may be splitted in two ions"
Fabian- I know that is true in the liquid state but is it true as a gas (how?!?!) or a solid (possible I guess .. does ice consist partially of ionised lattice such as salt?? ) and as my previous post doesnt the +ve ions in water actually consist of H3O+ ions?
One very recent article tells of the existance of water ice at 108 degrees farenheight in a nanometer thick layer associated with a nanocoating of diamond said to maybe be useful for artificial hip implants where the ice layer smooths out the submicroscopic defects of the diamond layer which may make for a longer lived implant. I'll try to rustle up the article. Found it:
http://www.sciencedaily.com/releases/2007/09/070905203345.htm
28 Sep 07
Originally posted by sonhouseHave we changed subject? I thought we were discussing the original problem of yours. Sorry.
The piece I posted mentions a salt-water ice that can be up to 7.5% NaCl. The piece says there are something like 10 or more kinds of ice.
One very recent article tells of the existance of water ice at 108 degrees farenheight in a nanometer thick layer associated with a nanocoating of diamond said to maybe be useful for artificial hip implants where the ic ...[text shortened]... rustle up the article. Found it:
http://www.sciencedaily.com/releases/2007/09/070905203345.htm
28 Sep 07
A new phenomena has just been observed, here is the article:
If two beakers with water in them are exposed to a high voltage electric field, the water molecules climb up the side of the beakers and come together in a water bridge up to 25 mm long! This is brand new science, you read it first here folks! Nothing to do with ice but it is startling behavior nonetheless!
http://www.physorg.com/news110191847.html
29 Sep 07
http://www.lsbu.ac.uk/water/ice1h.html
Generally going by the minimal unit cell should be sufficient. At the very bottom of this page, marked c it gives the unit cell of ice as containing 4 molecules of water. The question of water spontaneously ionising into H+ and OH- is a temperature dependant property and the proportion of ions to covalently bonded molecules reduces with temperature. For the purposes of defining the crystal structure, 4 molecules is enough to be sure you have ice. Any less and you can't be sure that you have a unit cell. any more in the required structure simply increases the amount of ice you have, but I think the original question was what the minimum was. (4)