Washington (ISJ) - If you drop an aluminium spoon in a sink full of water, the spoon will sink to the bottom. That's because aluminium, in its conventional form, is denser than water says Utah State University chemist Alexander Boldyrev.
But if you restructure the common household metal at the molecular level, as Boldyrev and colleagues did using computational modelling, you could produce an ultra-light crystalline form of aluminium that's lighter than water. Boldyrev, along with scientists Iliya Getmanskii, Vitaliy Koval, Ruslan Minyaev and Vladimir Minkin of Southern Federal University in Rostov-on Don, Russia, published findings in the latest online edition of The Journal of Physical Chemistry C.
The team's research is supported by the National Science Foundation and the Russian Ministry of Science and Education.
"My colleagues' approach to this challenge was very innovative," said Boldyrev, professor in USU's Department of Chemistry and Biochemistry. "They started with a known crystal lattice, in this case, a diamond, and substituted every carbon atom with an aluminium tetrahedron."
The team's calculations confirmed such a structure is a new, metastable, lightweight form of crystal aluminium. And to their amazement, it has a density of only 0.61 gram per cubic centimetre, in contrast to convention aluminium's density of 2.7 grams per cubic centimetre.
"That means the new crystallized form will float on water, which has a density of one gram per cubic centimetre," Boldyrev said.
Such a property opens a whole new realm of possible applications for the non-magnetic, corrosive-resistant, abundant, relatively inexpensive and easy-to-produce metal.
"Spaceflight, medicine, wiring and more lightweight, more fuel-efficient automotive parts are some applications that come to mind," Boldyrev explained. "Of course, it's very early to speculate about how this material could be used. There are many unknowns. For one thing, we don't know anything about its strength."
Still, he said, the breakthrough discovery marks a novel way of approaching material design.
"An amazing aspect of this research is the approach - using a known structure to design a new material," Boldyrev said. "This approach paves the way for future discoveries."
Source: Utah State University
Image courtesy: Utah State University