Graphene, why is it so strong, electrically conductive and flexible ?

[JakeEToth]

Homework Statement

I want to know why Graphene has the properties it has, I am really struggling to find out why graphene has the properties it does. Strength, I know graphene contains covalent bonds which are strong and that it has a hexagonal lattice structure. Electrical conductance I know that each carbon atom has one free valence electron as it is covalently bonded to only three other carbon atoms and that graphene has no band gap and a high current density and a high intrinsic mobility. Flexibility, I know the carbon atoms can rotate around their bonds and that is it !
So please could someone expand on all the points made and make even more I have googled, read many many articles and have emailed the graphene institution in Manchester with little success. Any help would be appreciated, thanks in advance !

 

[Naty1]

I was searching here to find why graphene electrons exhibit virtually zero mass...apparently called 'effective mass'...as in sold state physics...it's a better conductor than silver...

The most interesting sources I have found so far are Wikipedia under graphene and a reference
to Dirac Cones...here

http://idealab.talkingpointsmemo.com/2012/03/graphynes-stealing-graphenes-spotlight.php “The result is that the electrons in graphene behave as though they are relativistic particles with no rest mass, and so can whiz through the material at extremely high speeds.”
The carbon atoms in graphene are assembled in a distinctive hexagonal honeycomb or lattice-like pattern, and it was previously thought that only this structure could support Dirac cones.The new breakthrough reveals that other two-dimensional carbon configurations can support Dirac cones. These new materials could possesses new properties that graphene can only dream of..."The new theoretical generalization is Graphyne...

http://en.wikipedia.org/wiki/Graphyne

...Like in graphene, hexagonal graphyne has electric properties that are direction independent. However, due to the symmetry of the proposed rectangular 6,6,12-graphyne the electric properties would change along different directions in the plane of the material.[9]

I'll post anything of interest I find here...but I now see this is under INTRODUCTORY PHYSICS...
SOLID STATE PHYSICS might be better to elicit expert responses...