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Topic: Graphene - obvious questions... ?  (Read 4022 times)

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Offline nightmare00000

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Graphene - obvious questions... ?
« on: March 11, 2016, 07:36:34 PM »
Hello,

I have some questions connected with graphene on which I didn't find answers... Probably they are stupid but they persecute me :'( . But... "there are no stupid questions" :) .

1. Graphene deposited on copper foil (for example by CVD method - there are one layer on each side of copper) - is it as strong as "they talk - 100x than steel" or i could damage it putting into it a pencil? Or for example graphene obtained by tape-method like Geim and Novoselov ;)

2. The same composition and question about elasticity - graphene is 20-25% elastic - so if I bend this foil to much graphene layer will be degradated?

3. Are now methods which can produce only one layer sheets of graphene not deposited on other materials? But... do graphene sheet in this case will not roll up into CNT?

4. We now that graphene is a single-layer of graphite, so why are in articles definitions how many layers have some obtained graphene?


Sorry for some writing-mistakes but I'm not a native english speaker ;)


Regards. 

Offline Enthalpy

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Re: Graphene - obvious questions... ?
« Reply #1 on: March 13, 2016, 08:33:28 PM »
https://www.nobelprize.org/nobel_prizes/physics/laureates/2010/advanced-physicsprize2010.pdf

Any monoatomic layer is very weak. The comparison with steel divides the strength by the cross-section or by the mass per length unit.

Even that way, the comparison if grossly wrong and misleading, because thin materials are much stronger per section unit than thick ones. If you take whiskers of ceramic or steel, single fibres of polymer, graphite... they're amazingly strong per section unit, but as soon as you assemble many to make a rope, they lose the good properties. I still want to see a 1mm2 rope of carbon nanotubes and check its properties.

Materials bend more easily without breaking when they're thin. 50µm glass can be bent. A single-atomic-layer is much thinner.

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