carbon cousins: diamond, graphite and graphene

What do a diamond, a pencil and chicken wire have in common?


Diamonds and pencil lead (known as graphite) are chemically identical. Both are made of 100% carbon atoms. Nothing more, nothing less.
diamonddiamond molecule
How can that be when they’re so completely different in physical appearance?

It’s all in the molecular arrangement of the carbon atoms: the number of atoms in the arrangement and the bonds that form between them.

One type of arrangement creates a diamond molecule.
(mouseover the diamond to see)
pencilpencil molecule

Another arrangement makes a graphite molecule.
(mouseover the pencil to see)

Notice the distance between the atoms in each of these molecular patterns. The closer the atoms, the tighter the bond.

Notice the layers of grouped atoms in the graphite molecule. These layers can slough off easily, which is what happens when we write with a pencil. Each layer is composed of a hexagonal (6-sided) array of carbon atoms.

If you isolate one of these layers, you have graphene, a 2-dimensional material (one-atom-thick).

This is where chicken wire comes into the picture. Graphite’s layers and graphene’s single layer of carbon atoms are arrayed in a repetitive hexagonal configuration.

Graphene scientists have discovered that this hexagon array is remarkably strong — significantly stronger than the diamond array. Graphene’s unique structure gives it  other properties as well, an amazing combination of many impressive properties.

Graphene is so amazing and so impressive, some scientists call it a miracle material. When have you ever heard a scientist call anything miraculous?

Molecule images courtesy of Eastern New Mexico University, where you can read more about diamonds and graphite.

graphene is stronger and lighter than steel

graphene miracle material

The honeycomb array of graphene. The dots are carbon atoms. The lines are the bonds between them.

An amazing fact about graphene:

Graphene is the strongest lightest material on Earth. 

Graphene is 200 times stronger than steel and as much as 6 times lighter.

The secret is contained in the bonds between the individual atoms in the honeycomb array of carbon atoms that compose graphene.

Graphene is 100% carbon. So are diamonds, also known for their strength. The atomic structure of diamond is shown in figure a below.

allotropes of carbon

This illustration depicts eight of the allotropes (different molecular configurations) that pure carbon can take. Illustration created by Michael Ströck

a) Diamond
b) Graphite
c) Lonsdaleite
d) C60 (Buckminsterfullerene)
e) C540 (a fullerene)
f) C70 (a fullerene)
g) Amorphous carbon
h) single-walled carbon nanotube

graphene no break no bend

Another amazing fact about graphene:

If an ordinary piece of paper the length of a football field were as strong as graphene, you could hold it at one end with no breaking and no bending.

That being said, graphene is remarkably elastic. Graphene can be stretched 20% of its length and endlessly bend without breaking.

graphene is anti-bacterial

Another amazing fact about graphene:

Graphene kills bacteria, even the dreaded E. coli.

How is this possible?

Graphene slices the cell membranes of bacteria and extracts the cell’s phospholipids.

Another way in which graphene is a powerful anti-bacterial is its enhancement of the anti-bacterial properties of silver.

this is graphene

graphene sheet

Graphene is pure carbon. The dots you see are carbon atoms. The lines are the bonds between them.

Graphene is a 2 dimensional material, which means it is 1 atom thick.

Graphene has remarkable properties. It is about to revolutionize life on Earth.

This web site is a celebration of graphene’s discovery, magnificence and uses.

graphene a 2D material

Because it is only 1 atom thick, graphene has no volume, only surface.

The entire structure of graphene is exposed to that which contacts it — light, heat, a gas, a poison. Any molecule that touches graphene evokes a change in the graphene’s electrical properties, thereby acting as a signal of the presence of that molecule.

This makes graphene a versatile and invisibly small sensor device. A single molecule of a toxic gas can be sensed and signaled by graphene.