New 'water-oozing' nanorods could be used to harvest H2O

RICHLAND, Wash., June 13 (UPI) -- When an experiment-gone-wrong produced peculiar carbon-rich nanorods, researchers at the Pacific Northwest National Laboratory decided to take a closer look.

The found that as humidity levels increased, the nanorods lost weight. They used a microscope to get a close look and observed something rather spectacular: a fluid oozing out from between the tiny rods.

Further experimentation showed that the material absorbs water at lower humidity levels and spotaneously expels at higher humidity levels. Most materials absorb more water vapor as humidity levels rise.

"Our unusual material behaves a bit like a sponge," David Lao, PNNL post-doctoral research associate, said in a news release. "It wrings itself out halfway before it's fully saturated with water."

Lao helped produce the material, though he and his colleagues meant to make magnetic nanowires.

"Now that we've gotten over the initial shock of this unforeseen behavior, we're imagining the many ways it could be harnessed to improve the quality of our lives," added PNNL engineer David Heldebrant.

The researchers found an explanation for the phenomenon in a 2013 research paper that described a process called "solvent cavitation under solvo-phobic confinement."

The process describes the condensation of water between the confines of close hydrophobic materials. The scientific literature also yielded an explanation for the spontaneous evaporation of water confined to tiny spaces.

Until now, these processes were only theories. Now, they're properties of an actual material -- and they're on video.

Researchers believe the new material could be used to harvest water for drinking in arid regions like the desert. In addition to low-energy water harvesting and purification technologies, the material could also bolster sweat-wicking wearable fabrics.

Scientists described the novel rods and their potential applications in a new paper, published this week in the journal Nature Nanotechnology.

"But before we can put these nanorods to good use, we need to be able to control and perfect their size and shape," concluded lead researcher Satish Nune, a chemist at PNNL.