South West | Materials, extraction | Technology & innovation
Aluminum that floats in water?
25 Sep '17
Alexander Boldyrev, a chemist at the University of Utah, the U.S., and his colleagues at the Southern Federal University in Rostov-on-Don, Russia, have used computer modeling to predict the existence of a new aluminum modification that is twice as light as water. The research results have been published in English in The Journal of Physical Chemistry C.
In sharp contrast to the widespread assumption that an aluminum spoon will sink in water due to the fact that its density is 2.7 grams per cubic centimeter vs. water’s <1 gram per cubic centimeter, a new metastable ultra-light crystalline form of aluminum has been computationally designed in the project on the basis of a diamond lattice, which has an extremely low density of just 0.61 grams per cubic centimeter and floats in water.
Many chemical elements exist in the form of several basic substances called allotropic modifications. For example, graphite, graphene, soot, fullerenes and diamonds all have identical composition, but all display different properties because of differences in the way their carbon atoms are positioned.
According to Mr. Boldyrev, the research team used an unorthodox approach, in which all carbon atoms in the diamond lattice were replaced by aluminum Al4 tetrahedra.
The expected material was computed to be relatively stable, extremely light, resistant to corrosion, relatively inexpensive to produce, and non-magnetic. A substance with the above properties could be a boon in sectors like aircraft- and rocket-building. However, it’s premature to assert this with confidence, the scientists pointed out, as more research is needed to determine whether the material is strong and durable enough to qualify for such heavy-duty applications.