Collecting Water Out of Thin Air

Scientists from the Pacific Northwest National Laboratory (PNNL) have accidentally discovered microscopic stalks (nanorods) that can collect water from the air we breathe by first absorbing the water and then releasing it. The scientists were confused by the discovery initially, and thought that they were collecting this data from malfunctioning equipment.

The behavior of these nanorods is different from other materials because instead of releasing the water, most materials will continue to absorb more and more of it, like a sponge. However, these nanorods do not behave in this way. Their unique behavior of expelling water could be used to our benefit in a lot of different ways, such as in clothing or material that wicks away moisture from the body, or even a water collection system that requires low energy.

These nanorods were discovered by mistake when scientists were trying to create magnetic nanowires. Instead, they created carbon nanorods that acted strangely in humid conditions—losing weight despite increased humidity. The scientists realized that this unusual behavior was hypothesized back in the 1990s--water could vaporize if materials that repelled water tightly surrounded it, or water can vaporize if it's confined to a small space less than 1.5 nanometres wide.

It is clear that this discovery could have exciting uses, including harvesting water in exceptionally dry climates such as deserts, creating a new way for us to separate and purify water. However, before we can pull that off, we will need to make the process more efficient because researchers say that only 10 to 20 percent of the material expels water. This is a low percentage. The scientists would like to increase this percentage and make it much more efficient. 

This water-collecting discovery could eventually be used to improve all of our lives on this planet, but before we can get to that point, one team engineer, David Heldebrant, points out that scientists must be able to control the size and the shape of these nanorods. With this level of control and precision, the implications are exciting and full of potential.