Image: PNNL researchers saw for the first time a phenomenon that was theorized more than 20 years ago. Shown here is a PNNL illustration of the phenomenon, "solvent cavitation under solvo-phobic confinement," which PNNL researchers saw occur with carbon-rich nanorods they mistakenly created. PNNL's viewing of the phenomenon involved liquid spontaneously evaporating after being confined within tiny spaces in between touching nanorods. Image from S. Nune et al, Nature Nanotechnology, 2016. (Pacific Northwest National Laboratory)After their nanorods were accidentally created when an experiment didn't go as planned, the researchers gave the microscopic, unplanned spawns of science a closer look.
Chemist Satish Nune was inspecting the solid, carbon-rich nanorods with a vapor analysis instrument when he noticed the nanorods mysteriously lost weight as humidity increased. Thinking the instrument had malfunctioned, Nune and his colleagues moved on to another tool, a high-powered microscope.
They jumped as they saw an unknown fluid unexpectedly appear between bunches of the tiny sticks and ooze out. Video
recorded under the microscope is shaky at the beginning, as they quickly moved the view finder to capture the surprising event again.
The team at the Department of Energy's Pacific Northwest National Laboratory
would go on to view the same phenomenon more than a dozen times. Immediately after expelling the fluid, the nanorods' weight decreased by about half, causing the researchers to scratch their heads even harder.
A paper published today in Nature Nanotechnology describes the physical processes behind this spectacle, which turned out to be the first experimental viewing of a phenomenon theorized 20-some years ago. The discovery could lead to a large range of real-world applications, including low-energy water harvesting and purification for the developing world, and fabric that automatically pulls sweat away from the body and releases it as a vapor. (Video
"Our unusual material behaves a bit like a sponge; it wrings itself out halfway before it's fully saturated with water," explained PNNL post-doctoral research associate David Lao, who manufactured the material.
"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," said PNNL engineer David Heldebrant, one of the paper's two corresponding authors.
"But before we can put these nanorods to good use, we need to be able to control and perfect their size and shape," added Nune, the paper's other corresponding author.