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Graphene Might Lead to Improved Bullet-Proof Vests and Hydrogen Fuel Cells


Image credit: CORE-Materials, “Model of Graphene Structure,” via Flickr. CC BY-SA 2.0

When the amazing material—graphene was discovered ten years ago, scientists and engineers have expected its practical application ever since.

With thickness of a single atom thick, such carbon sheets are regarded as the thinnest material in the world and at the same time they are the strongest as well. Therefore it is not completely surprising that scientists are intended to use it for making body armor. Based on the miniature ballistic tests, scientists have found that the performance of graphene is twice better than the material used in bulletproof vests in the traditional way, making it possible that it could be used to protect police officers and soldiers.

Graphene is composed of a sheet of single carbon atoms which are arranged in the structure of a honeycomb. In addition to its incredible strength, graphene is also very good at conductivity of heat and electricity as well as rust resistance together with outstanding mechanical and optical properties. Being advantageous in such impressive range of characteristics, graphene is remarkably lightweight, so scientists are interested in making it as a good addition to body armor.

It is unfortunate that testing it out is not like a simple thing to fire bullets through it, and then observe the following occurrence, because the impact would obliterate atom-thick material. Therefore, different tactic has to be applied to examine its vigor. To this end scientists from the University of Massachusetts-Amherst went for a miniaturized ballistics test.

According to the description in the journal Science, the researchers resorted lasers to superheat gold filaments, which functioned just like gunpowder and fired out small silica spheres, namely “microbullets,” at sheets of graphene, that is ranged in thickness from 10 to 100 nanometers.

In comparison of the kinetic energy of the spheres before and after they speared the sheets, researchers discovered that graphene had dissipated this energy in the way in which it warped into a cone shape at the location of impact, and then cracked outward. Although a weakness was found in these cracks, the material did perform twice better than Kevlar, the lightweight fiber previously used for body armor. In addition, graphene was also able to absorb between 8 and 10 times the impacts that steel could withstand.

It is hoped in the future that scientists could solve such cracking problem through combining it with other kinds of materials so as to create a composite instead.

Furthermore, another paper published in recent edition of Nature revealed the new property of graphene: its permeability to protons, which is unknown before. This latest finding allow scientists to explore the possibility that it could be applied for better improvement of fuel-cell technology, or even for collecting hydrogen from the atmosphere.

Hydrogen fuel cells could generate electrical energy by the way of the reaction between hydrogen and oxygen. They are dependent on semi-permeable membranes that would let protons pass through but stop other particles. However materials used at present would let some hydrogen fuel leak through, thus decreasing the system’s efficiency. Instead, it seems that graphene is impermeable to everything except for protons, which means that it could help offer a satisfactory solution to the problem.

As far as this newly identified property of graphene is concerned, in future it could be used as a sieve to extract hydrogen from air, by doing so, it would allow us to pump fuel from the atmosphere and produce electricity from it. Although this prospect is exciting, it is merely speculation at the moment.

Source: ScienceNew ScientistBBC NewsScience AlertE&TNature and Nature