New material absorbs oxygen from air

Researchers have synthesised a material that can bind and store oxygen in high concentrations which can be released again when needed.

PTI| Updated: Oct 01, 2014, 14:11 PM IST

London: Researchers have synthesised a material that can bind and store oxygen in high concentrations which can be released again when needed.

Just one spoon of the substance is enough to absorb all the oxygen in a room, said researchers from the University of Southern Denmark.

The new material is crystalline, and using x-ray diffraction the researchers have studied the arrangement of atoms inside the material when it was filled with oxygen, and when it was emptied of oxygen.

"An important aspect of this new material is that it does not react irreversibly with oxygen - even though it absorbs oxygen in a so-called selective chemisorptive process," said researcher Christine McKenzie.

"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 McKenzie.

The researchers' work indicates that the substance can absorb and bind oxygen in a concentration 160 times larger than the concentration in the air around us.

"It is also interesting that 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," McKenzie said.

Once the oxygen has been absorbed it can be stored in the material until it has to be released. The oxygen can be released by gently heating the material or subjecting it to low oxygen pressures.

"We see release of oxygen when we heat up the material, and we have also seen it when we apply vacuum. We are now wondering if light can also be used as a trigger for the material to release oxygen - this has prospects in the growing field of artificial photosynthesis," said McKenzie.

The key component of the new material is the element cobalt, which is bound in a specially designed organic molecule.

Depending on the atmospheric oxygen content, temperature, pressure, etc it takes seconds, minutes, hours or days for the substance to absorb oxygen from its surroundings. Different versions of the substance can bind oxygen at different speeds.

With this complexity it becomes possible to produce devices that release and/or absorb oxygen under different circumstances - for example a mask containing layers of these materials in the correct sequence might actively supply a person with oxygen directly from the air without the help of pumps or high pressure equipment.

"When the substance 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," said McKenzie.

"This could be valuable for lung patients who today must carry heavy oxygen tanks with them. But also 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 surrounding air or water," McKenzie said.