Scientists from the University of Southern Denmark, working with others from Sydney University in Australia, have developed a ‘breathing’ crystalline material that could potentially replace oxygen tanks, as well as having implications for the treatment of respiratory illnesses. The key to the far-reaching implications of such an invention is the ability of this material to absorb and release oxygen without reacting to it.
In the image above, The material can be scene to change color as it absorbs and releases oxygen. The crystals turn black as they take in oxygen and then pink as they release it.
Perhaps the most simply and obvious way to visually demonstrate the corrosive power of oxygen is to take a bite from an apple and then leave it exposed to the air; very quickly, the meat of the apple will turn brown. This is a basic display of the power of oxygen – given enough time, almost any material, organic or otherwise, will be irreversibly changed by exposure to oxygen. This new synthetic material – the main component of which is the metal cobalt – has the ability to suck in large quantities of oxygen and store it without suffering the corrosion or decomposition that comes with prolonged exposure to the gas. In addition, the material is then able to expel the oxygen – and controlling this absorption and expelling of oxygen is key to producing compact amounts that could replace oxygen tanks, in addition to having far-reaching implications in the medical and industrial fields.
Professor Christine McKenzie, one of the team that was able to develop the crystals, explained the potential of the substance – a few grains of which has the capability of storing a lungful of oxygen; “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.” she said. Two of the most obvious uses are the replacement of cumbersome oxygen tanks for scuba divers, as well as patients who require them to aid breathing. “When the material is saturated with oxygen, it can be compared to an oxygen tank containing pure oxygen under pressure; the difference is that this material can hold three times as much oxygen.” McKenzie says.
Continuing with the implication for divers, she pointed out that the crystals are able to extract oxygen from water. “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 will not need to bring more than these few grains.”
In laboratory experiments, the scientists found that they were able to affect the release of oxygen from the crystalline material by applying heat and also by pressure, using a vacuum. The team is now working to find out if light can also trigger this exhalation. The rate at which the substance absorbs oxygen is subject to a number of variables, including pressure and temperature and the researchers in Denmark, aided by a team at the University of Sydney, who have used specialized equipment to take the measurements, have been able to develop varying versions of the crystals which absorb oxygen at different rates.
Tiny amounts of metal are instrumental to the absorption of oxygen; living things use metal in such a process. In humans, iron in the body facilitates the body’s oxygen intake. In this new material, cobalt has been employed because it “gives the new material precisely the molecular structure that enables it to absorb oxygen from its surroundings.” In addition to replacing oxygen tanks, these ‘breathing’ crystals could have far-reaching benefits for any activity or process that requires the processing of pure oxygen, but where size, space and weight are a factor.
Graham J Noble