Recently, the team announced the successful synthesis of a material that’s capable of absorbing oxygen from the air around it, and subsequently storing it in high concentrations. Led by nanobioscience professor Christine McKenzie, the team claims that just 10 liters (about 2.6 gallons) of the crystalline substance is enough to absorb all the oxygen from a room. A number of variables dictate how quickly the new substance works, including atmospheric oxygen content, temperature and pressure. Time for absorption ranges from a matter of seconds to a number of hours or even days. The substance is able to store oxygen at a concentration up to 160 times greater than the oxygen concentration in the air, but its most remarkable quality is its ability to release the oxygen at a later stage. McKenzie says of the substance that “an important aspect of this new material is that it does not react irreversibly with oxygen,” and goes on to describe it as being equivalent to “solid artificial hemoglobin.”
Oxygen from the lungs binds to hemoglobin, a molecule in the human blood stream, in a process that allows the oxygen to be transported and subsequently deposited around the body. The new material acts in a similar way, storing oxygen and then transporting and releasing it wherever and whenever it is needed. It shares other similarities with hemoglobin: just as hemoglobin requires iron to function, so too the newly developed substance depends upon a metallic component. Each of the crystalline structures that make up the substance includes a cobalt foundation, to which oxygen ions bind. Because of the lattice-like nature of the material, it can store a large amount of oxygen in a relatively small space, changing color from pink to black as it does so. In order to trigger the oxygen’s release, the substance must be exposed to heat or a lower external pressure; by controlling these factors, it’s possible to dictate when that will take place. According to McKenzie, “the material can absorb and release oxygen many times without losing the ability. It is like dipping a sponge in water, squeezing the water out of it and repeating the process over and over again.”
Potential uses for the new material include the manufacture of devices that allow the absorption or release of oxygen under a series of different circumstances. For example, a medical patient who must carry around heavy oxygen cylinders may one day be able to replace those cylinders with a lightweight breathing apparatus that utilizes the new material to generate oxygen. It has also been suggested that the substance may be used to facilitate artificial photosynthesis, or create advanced vehicle fuel cells. Thanks to the substance’s ability to absorb oxygen from water as well as from air, McKenzie thinks it may someday be used to develop revolutionary breathing equipment for divers. “Divers may one day be able to leave the oxygen tanks at home and instead get oxygen from this material as it filters and concentrates oxygen from the surrounding air or water,” she says “A few grains contain enough oxygen for one breath, and as the material can absorb oxygen from the water around the diver and supply the diver with it, the diver would not need to bring more than these few grains [with them underwater].”
However, despite being lauded across Internet forums and in several major newspapers as having the potential to change the way we dive today, there are some obvious questions that must be answered before such dreams can become a reality. As all divers know, we rely not on “oxygen tanks,” but on cylinders that contain compressed air, usually with oxygen content of 21 percent. Under pressure, pure oxygen quickly becomes toxic, so to dive solely on the oxygen released by the new material is not realistic. If this substance is to help revolutionize diving, developments must allow it to be mixed with nitrogen, making it safe to breathe at depth.
As tantalizing as the prospect of diving without cylinders may be, we’re still a long way from achieving such a dream, but perhaps the material created by McKenzie and her team will prove to be the first step in doing so.