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I am not very familiar with graphene but I would like to know how well it scales up from the molecular/nano scale to the macroscopic. I took a Material's Engine

by elteto 14y ago

I am not very familiar with graphene but I would like to know how well it scales up from the molecular/nano scale to the macroscopic. I took a Material's Engineering class in college and I remember the professor saying that the "theoretical" strength of materials (in general) was supposed to be extremely high, orders of magnitude higher than what you find in real life. The disparity is a result of imperfections in the crystal lattices of the materials. You can probably build a graphene tube 50nm in length and find that at that scale it has all those superior properties, especially since at that size you are almost handling molecules individually and can arrange them correctly. But what happens when you go up in the scale? Will it retain all of those wonderful properties to the same extent?

adrusi 14y ago
a related video link points out that researchers have yet to find a single atom out of place in the lattice http://richannel.org/how-to-make-graphene http://richannel.org/how-to-make-graphene
tcpekin 14y ago
Graphene is simply a single layer of carbon atoms. If you roll one up, voila, you have a carbon nanotube you've been hearing about for the past 10 years. Carbon nanotubes (CNTs) have similar properties as graphene (act as a metal or a semiconductor, are the "strongest materials known, etc.[1]). From what I understand, it is very difficult to make large sections of pure graphene or long CNTs. As long as they're pure, they remain strong, and therein lies the difficulty of graphene and CNT production. Like you said, the impurities do weaken CNTs and graphene. The impurities can be contaminants which occupy a carbon location, or missing carbon atoms, forcing the lattice to reconstruct. According to [1], this can lower the tensile strength of a carbon nanotube by up to 85%. The problem with manufacturing long CNTs and large areas of graphene is that it is thermodynamically impossible to, on a large scale, have a perfect lattice. The imperfections will weaken the entire structure. So yes, as you go up in scale, the incredible/fantastic properties will just become impressive. [1] http://en.wikipedia.org/wiki/Carbon_nanotube http://en.wikipedia.org/wiki/Carbon_nanotube *I currently study materials science and can produce literature upon request. Also this is from the top of my head so it may contain some errors.

by elteto 14y ago

adrusi 14y ago

a related video link points out that researchers have yet to find a single atom out of place in the lattice http://richannel.org/how-to-make-graphene http://richannel.org/how-to-make-graphene

tcpekin 14y ago

Graphene is simply a single layer of carbon atoms. If you roll one up, voila, you have a carbon nanotube you've been hearing about for the past 10 years. Carbon nanotubes (CNTs) have similar properties as graphene (act as a metal or a semiconductor, are the "strongest materials known, etc.[1]). From what I understand, it is very difficult to make large sections of pure graphene or long CNTs. As long as they're pure, they remain strong, and therein lies the difficulty of graphene and CNT production. Like you said, the impurities do weaken CNTs and graphene. The impurities can be contaminants which occupy a carbon location, or missing carbon atoms, forcing the lattice to reconstruct. According to [1], this can lower the tensile strength of a carbon nanotube by up to 85%. The problem with manufacturing long CNTs and large areas of graphene is that it is thermodynamically impossible to, on a large scale, have a perfect lattice. The imperfections will weaken the entire structure. So yes, as you go up in scale, the incredible/fantastic properties will just become impressive. [1] http://en.wikipedia.org/wiki/Carbon_nanotube http://en.wikipedia.org/wiki/Carbon_nanotube *I currently study materials science and can produce literature upon request. Also this is from the top of my head so it may contain some errors.