The Era Of Graphene Has Not Yet Arrived
But it has been born for ten years, my transparent mobile phone where?
In fact, in 2012, Konstantin Novoselov, who won the Nobel Prize for graphene, and his colleagues published an article on "Nature" to discuss the future of graphene, two years of development Also basically proof of their prediction. He believes that as a material, graphene "the future is bright, the road is tortuous", although it may play a major role in the future, but before several major difficulties to overcome, this scene will not come. More importantly, taking into account the huge cost of industrial renewal, the benefits of graphene may not be enough to make it simply replace the existing equipment - its true prospects, perhaps because of its unique features tailor-made new applications The
What is graphene in the end?
Graphene is the first material to be found by a single layer of atoms. The carbon atoms are interconnected into hexagonal meshes. Pencil with graphite is equivalent to countless layers of graphene stacked together, and carbon nanotubes are graphene rolled into a tube. Graphite, graphene, carbon nanotubes and globin.
Due to the chemical bond between the carbon atoms, graphene is tenacious: can bend to a large angle without breaking, but also against high pressure. And because only one layer of atoms, electronic movement is limited to a plane, it brought a new electrical properties. Graphene is transparent in visible light, but airtight. These features make it very suitable as a raw material for protective and transparent electronic products. But suitable for the right, really do not come so fast.
One of the questions: the preparation method. Many of the studies show us the amazing characteristics of graphene, but there is a trap. These wonderful features are very demanding on sample quality. To obtain the best of electrical and mechanical properties of graphene samples, the need for the most time-consuming and costly means: mechanical stripping method - with adhesive tape on the graphite, the artificial stripping of graphene. Do not laugh, Novo Shawlov in 2004 they are so prepared graphene.
Although the required equipment and technical content seem to be low, but the problem is the success rate is lower, get some samples to do research can also, industrial production? joke. To industrialization, this means no use. Even if you have mastered the world's graphite mine, one day can peel a few pieces ... ... of course we now have a lot of other ways to increase production and reduce costs - the trouble is that these methods of product quality and fall. We have liquid stripping method: the graphite or similar carbonaceous material into the surface tension of ultra-high liquid, and then ultrasonic bombing of graphene snowflake deep down. We have a chemical vapor deposition method: let the carbon-containing gas in the copper surface condensation, the formation of graphene thin layer and then stripped. We have a direct growth method, in the middle of the two layers of silicon directly to try to grow a layer of graphene. There is also a chemical redox method, by the insertion of oxygen atoms to separate the graphite sheet, and so on. There are many methods, but also have their own scope of application, but so far has not really suitable for large-scale industrialization of industrial production technology.
Why can not these methods make high quality graphene? for example. Although the central part of a piece of graphene is a perfect six-membered ring, it is often disrupted at the edge and becomes a five- or seven-membered ring. This does not look great, but the chemical vapor deposition method produces "a piece" of graphene is not really complete, from one point of growth out of a. It is actually a number of points at the same time the growth of the "polycrystalline", and there is no way to ensure that these points grow out of small pieces can be completely aligned. Thus, these deformed rings are not only distributed on the edge, but also exist in every "one" to do this out of the graphene, become a structural weakness, easy to break. Worse still, this break of graphene does not heal like polycrystalline metals, and is likely to extend it all the time. The result is that the strength of the whole graphene is halved. Material is a troublesome area, like fish and bear's paw is not impossible, but certainly not so fast.