Research team bends individual tetrapod nanostructures

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Regarding new , scientists are primarily

interested in one thing: What properties do they have, and how do they behave under different conditions? This also determines the new possible uses of the materials. "In order to predict the overall mechanical behaviour of a network material, we must investigate the individual building block structures with which it is constructed," explained Dr. Yogendra Mishra, materials scientist in the working group "Functional Nanomaterials" at the CAU. Aerographite is constructed of tetrapods, carbon-based 3-D nanostructure which consist of four hollow arms. When combined together, they form a porous, extremely lightweight network, and bring the weight of aerographite down to just 0.2 milligrams per cubic centimetre. ''Because of this unique structure, the material exhibits a high mechanical strength as well as a very high surface, from which interesting physical and chemical features originate,'' says Daria Smazna, a doctoral student in the project.
The international research team led from Kiel has now managed to show that aerographite is extremely foldable. "In general, bulk materials like carbon or metal are not foldable, but due its special structure our carbon networks are highly flexible and mechanical stable too", explained Professor Rainer Adelung, head of the Functional Nanomaterials Chair. You could imagine it much like a sheet of paper. "A flat sheet of paper offers no resistance, if you hold it on one side, it simply hangs down. However, if we roll it up or crumple, it attains a certain degree of stability," continued the materials scientist. It therefore depends on the geometrical arrangement within the material. The special shape of the tetrapods made the researchers suspect that they could be folded - despite the lightness of aerographite. This is because the individual arms have very thin walls and they are hollow inside. "This allows them to be bent at so many different places, even reversibly. They automatically go back to their original shape, without sustaining any damage," explained Mishra. "Just like an accordion, the three-dimensional object can be folded into a two-dimensional form, and then unfolded again."


Read more at: https://phys.org/news/2017-08-team-individual-tetrapod-nanostructures.html#jCp