Diamond, which on Earth is one of the hardest materials of natural origin, has long been acting as a kind of standard in materials science and other fields of science related to this. But scientists and engineers are constantly looking for opportunities to create new artificial materials, which in terms of parameters should exceed the best of what nature can offer us. And not so long ago, a group of scientists from the University of California at Irvine created a new type of carbon nanogrid, which has a much higher density strength index than diamond.
The new material is a typical nanogrid, a porous ordered structure consisting of vertical, horizontal cross-beams and inclined struts made of carbon, the substance of which diamonds are made. The creation of such nanogrids has been practiced by scientists for a long time, but all such materials created earlier had cylindrical-shaped lattice elements, the production of which is much simpler than the production of other-shaped elements. It is the shape of the lattice elements that distinguishes the material created by California scientists, these elements are flat plates of a certain thickness.
“Materials based on a lattice, whose elements are round, are certainly interesting, but not so effective in terms of their mechanical properties,” the researchers write. “A new class of plate nanogrids like the ones we created is more durable and more cruel than all other types of similar materials. “
In addition to the new structure of the nanogrid, the researchers used a new method of its production. A very thin laser beam was focused inside a drop of a special viscous polymer material sensitive to ultraviolet light. Laser light causes the material to polymerize (harden) at the point where the beam focuses, and moving the beam allows the formation of plates with a thickness of 160 nanometers. After creating the structure of the nanogrid using a laser, the material was placed in a furnace, where at a temperature of 1650 degrees Celsius the remains of unused polymer were removed from it, and the hardened polymer as a result of the pyrolysis process turned into pure carbon.
The result was a material that was superior to similar material with cylindrical lattice elements by 639 percent in strength and 522 percent in stiffness. “The mechanical properties of such material have long been theoretically calculated, and we became the first group to confirm them experimentally,” the researchers write, “as a result, we got material with unprecedented values of its mechanical characteristics.”
One of the areas of application of the new material is, of course, the field of design and production of space technology and other areas in which the key requirements are the use of lightweight materials with low density, but providing strength and hardness at the level of ordinary monolithic materials of natural or artificial origin.