It only takes about 10 liters of a newly-developed form of crystalline cobalt salt to steal the air from a room, or at least the 21 percent or so of that air comprised of oxygen. Given the right conditions, with the temperature and atmospheric pressure just so, it could take as little as seconds for the material to do its work. Then, by gently heating the material or subjecting it to low surrounding oxygen pressures, the material can be prompted to release its O2 payload back into the air.
This new crystalline oxygen "sponge" comes courtesy of researchers at the University of Southern Denmark. As with most things that remove oxygen from the air, the material works by binding chemically to the individual oxygen molecules. You're doing something similar as you read this in your lungs, as incoming oxygen grabs hold of the hemoglobin proteins found in blood, thanks to nice chemical "handholds" in the form of iron ions.
As with hemoglobin, the synthetic oxygen sponge created by the Danish researchers features a reversible chemical binding process. This is not always the case with reactions—the chemical reaction behind combustion, for example, swipes oxygen from the air, but the products, carbon dioxide and water, are too stable for the process to switch directions. That is, there is no unburning.
"The material is both a sensor, and a container for oxygen—we can use it to bind, store and transport oxygen—like a solid artificial hemoglobin," said Christine McKenzie, a nanobioscience professor and principle investigator behind the new research, in a statement. What's more, it appears that the material is capable of doing this again and again, indefinitely, without losing its oxygen soaking abilities.
The black crystals are oxygen-soaked, the right are not. Image: McKenzie et al
The crystal structure of the salt provides a neat lattice for storing a great deal of oxygen in a very small amount of space. Each single crystal structure features two nitrate ions bound to a metallic molecular substructure, like a nitrogen house built on a cobalt foundation. It's really a nitrogen mobile home, however, as the introduction of oxygen to the neighborhood means the nitrogen ions very quickly split town. The oxygen ions then set up shop themselves on the cobalt foundation.
This happens very quickly throughout the entire crystal structure, at least until all of the freely roaming oxygen is gone. The opposite migration, nitrogen moving back in, can happen just as fast.
The cobalt foundation is crucial for this sort of oxygen sponge to work. As oxygen binds to iron in your blood, it binds to the metal cobalt here. "Cobalt gives the new material precisely the molecular and electronic structure that enables it to absorb oxygen from its surroundings," McKenzie explained.
"This mechanism is well known from all breathing creatures on earth," she said. "Humans and many other species use iron, while other animals, like crabs and spiders, use copper. Small amounts of metals are essential for the absorption of oxygen, so actually it is not entirely surprising to see this effect in our new material."
The Danish researchers imagine one scheme for this technology in particular. While providing extra oxygen to someone, whether they're a COPD patient or on the top of Mount Everest, necessarily involves the use of complicated pumps and tanks, McKenzie imagines a simple mask layered with oxygen-loaded cobalt salts.
The material is just as capable of absorbing oxygen from water as air, so it might one day be possible for divers to spend long periods of time underwater without tanks.
Update 10/1: We've updated this post to correct a calculation error on the part of the researchers that suggested the oxygen-absorbing compound is far more efficient than it actually is. In an emailed statement, a representative for Syddansk University said "I am just updating our story on our website, because it turns out that Prf McKenzie made a calculation error. Pls note that it is not a SPOONFUL of this stuff, that we need to rid a room of oxygen. It is a bucket (10 litres). We apologize." Motherboard apologizes for any confusion.