Fascinating new "oxygen stealing" material. Possible uses for diving?

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Cixelsyd

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This article:

New material steals oxygen from the air

is giving me visions of this:

b6dzfhzdof1jxa9qwfsi.jpg

Not really, of course, but it does seem interesting. A material that could pull oxygen directly from water could prove very useful. The article seems to gloss over the fact that air is not the same as oxygen and the problems in diving with breathing pure oxygen, but I could see a highly compact rebreather utilizing something like this as part of its design. Even on open circuit, it seems like this material could be mixed in and oxygen added to an inert gas on demand and allow for smaller tanks or longer bottom times.
 
Maybe my physics is lacking but how can a material store a volume of gas greater than it's own volume without compression. Wouldn't a teaspoon of this material be able to store no more than a teaspoon of 02? What process compresses a rooom full of 02 into that size?
 
Wouldn't a teaspoon of this material be able to store no more than a teaspoon of 02? What process compresses a rooom full of 02 into that size?

The oxygen molecules are bound to the solid material and are therefore not in a gaseous state anymore. So, gas compression does not apply: put simply, the molecules don't constantly bump into each other anymore, and therefore don't need as much space. The same principle lets your body hold about 70 times the amount of oxygen it would hold if oxygen was simply dissolved in the blood, because the oxygen molecules are bound to Hemoglobin.

I am skeptical if this material would be able to store and release gaseous oxygen at a fast enough rate for diving applications.
 
i'm thinking the need to heat the crystals to over 100c to release the o2 will need to be dealt with before we worry too much about scuba applications.
 
What process compresses a rooom full of 02 into that size?
Condensation. There's far less space between the molecules of liquids and solid than those of gases. The difference in density between water and water vapor is an example that everybody probably understands. One mole of water weighs a hair over 18 grams, and has a volume just over 18ml. The same mass as water vapor has a volume of 22.4 liters, or 22,414 ml. That means a given volume of water has 1245 times as many molecules as the same volume of water vapor (at standard temperature and pressure). In the case of oxygen, the liquid is 860 times as dense as the gas.

Of course plain old condensation wouldn't quite do the trick. A modest room that's 8.6 x 10 x 10 feet would have a volume of 860 CF, so condensed to a liquid the oxygen in the room would have a volume of about .209 CF (about half the actual physical volume of an AL 80). That much O2 would weigh about 14.4 pounds (860CF * .08 lb/CF * 20.9%). Let's assume the spoon the article referred to is a big ass cooking spoon with a volume of 4 ounces, and that the material itself is weightless. Bonding that 14.4 lbs of O2 to the piece of material with a volume of 4 ounces would result in a density of over 3000 lbs/CF, which is more than 4 times the density of lead. Compressing that O2 into a 4 ounce scuba tank would require a pressure of almost 43,000 atmospheres (at which point the ideal gas law won't apply, because the volume of all those molecules becomes significant).

This must be a very special material, indeed.

giving me visions of this:

Even if the material allowed you to absorb and immediately use the O2 dissolved in the water (and ignoring the problem of breathing 100% O2 at depths of more than 20') I still can't imagine that it would actually allow you to breathe. At 4 ATA and 0ºC the maximum solubility of O2 in seawater is about 45mg/L. A SAC rate of .5 CF/minute means you're breathing about 0.1 CF of O2 per minute, which is about 3.6 grams. At 99' you'd need 14.4 grams of O2, which means you'd have to use all of the O2 in 320 liters (320 kilos, 704 lbs) of water every minute. Solubility is proportional to pressure, so the same would be true at any reasonable depth, but solubility decreases as the temperature increases. Just moving enough water would require considerable effort no matter how efficient the absorbtion and exchange process is.

An ability to accurately blend bonded, low volume, O2 with N2 from a cylinder would potentially be useful. An AL 80 with 100% N2 would have the same effective size as a 117 CF tank of EAN 32. That would certainly allow for much longer dives or a greater margin of safety for those who don't pay enough attention to their SPG. On the downside, the need to blend O2 with a diluent would effectively make every OC diver a rebreather diver, with a chance to breath a mix that's hypoxic or toxic.

And of course there's still the matter of how to release the O2 to make it useful.
 
Even if the material allowed you to absorb and immediately use the O2 dissolved in the water (and ignoring the problem of breathing 100% O2 at depths of more than 20') I still can't imagine that it would actually allow you to breathe. At 4 ATA and 0ºC the maximum solubility of O2 in seawater is about 45mg/L. A SAC rate of .5 CF/minute means you're breathing about 0.1 CF of O2 per minute, which is about 3.6 grams. At 99' you'd need 14.4 grams of O2, which means you'd have to use all of the O2 in 320 liters (320 kilos, 704 lbs) of water every minute. Solubility is proportional to pressure, so the same would be true at any reasonable depth, but solubility decreases as the temperature increases. Just moving enough water would require considerable effort no matter how efficient the absorbtion and exchange process is.

Now I'm having visions of entire reefs dying as a boatload of divers swims by and sucks up all of the available O2 in the water. :wink:


An ability to accurately blend bonded, low volume, O2 with N2 from a cylinder would potentially be useful. An AL 80 with 100% N2 would have the same effective size as a 117 CF tank of EAN 32. That would certainly allow for much longer dives or a greater margin of safety for those who don't pay enough attention to their SPG. On the downside, the need to blend O2 with a diluent would effectively make every OC diver a rebreather diver, with a chance to breath a mix that's hypoxic or toxic.

And of course there's still the matter of how to release the O2 to make it useful.

Minor details!

Actually, thanks for your insight. Nice to get someone who knows the physics involved to offer a critique.
 
Actually, thanks for your insight. Nice to get someone who knows the physics involved to offer a critique.
I think its chemistry and not physics? at room temperature a chemical? reaction slowly occurs over several days that allows the o2 to bond with the special crystal forming a new compound (kind of like rust reaction but not really). they then apply large amounts of heat to force the new compound to unbind the o2 and "mostly" return to its original state.

their paper (which is a very difficult read) gives little info on the viability of manufacturing usable amounts of the material and also indicates they had to take special precautions due to the danger of the materials involved in the manufacturing process. i did not notice any indication regarding the safetyness of the special crystals, nor how much they were able to actually create. it does not appear to be "spoonfuls".

the concept has been around for more than a decade as their paper / university website cites other work from early 2000's.

the article appears to be sensationalism jouralism. this opinion is backed up by the overt presence of adds and spam on the website. i would not consider it a reliable source of information.
 
Maybe it could be applied to mixing applications. It might replace the 300 cu ft O2 bottles used for blending nitrox in shops and my garage. Just heat the material and introduce it into the air compressor.like done with the bottles.
 
https://www.shearwater.com/products/peregrine/

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