Listing the properties of new wonder material graphene makes it sound a lot like listing Superman’s attributes. Lighter than a feather. More conductive than copper. Able to leap tall buildings…well, maybe not — but it is stronger than steel and could find its way onto your jobsite in the future.
So what, exactly, is graphene and what might it do for you?
The Miracle Material
Graphene is made up of carbon atoms arranged in a honeycomb lattice pattern. It forms a nearly transparent sheet about one atom thick, and is 200 times stronger than steel, yet six times lighter. Almost two-dimensional instead of three-dimensional, graphene interacts with light and other materials in unique ways. For example, it only absorbs about 2% of light, and is impermeable even to lighter gases like hydrogen and helium. It’s also a highly efficient conductor of both heat and electricity.
Perhaps one of the most promising future uses of graphene is in the production of lightweight, yet super strong composite materials.
Carbon Nanotubes and Carbon Nanofibers
As we mentioned in our smart nano-materials post, carbon nanotubes have some incredibly handy uses in construction. So does a similar material called a carbon nanofiber. Carbon nanotubes are just layers of graphene wrapped into perfect cylinders. Carbon nanofibers are also made from layers of graphene, this time arranged into the shapes of stacked cones, cups, or plates.
These materials can be combined with traditional bulk building materials to improve or add new properties to the bulk materials. Possible applications include replacing steel cables on suspension and cable-stayed bridges with much stronger carbon nanotubes. Carbon nanotubes can also be incorporated into concrete to act as supportive fibers. The resulting concrete can handle stress and compression far better than traditional concrete alone.
Flexibility: Phone Screens and Building Skins
The electronics industry has embraced graphene, and it’s not hard to see why. This material is perfect for touchscreens, with its superior strength, flexibility, and electric conduction. Several manufacturers are already racing to bring the first graphene-based smartphone screen to market. While purely theoretical at this point, another exciting possibility for graphene is in creating surface “skins” for both the inside and outside of a building. Just about all of graphene’s properties make it ideal for such an application.
Its strength and flexibility could reduce repair costs for the building, and its thermal and electrical conducting properties could help control the interior atmosphere.
Graphene presents great promise in creating the building materials of the future…but it does have one major drawback: At least for structural applications, it likely can’t be used alone. According to a team of scientists from Rice University and the Georgia Institute of Technology, graphene is so brittle that the tiniest crack can turn it into, essentially, a big sheet of shattering glass. This team layered two single-atom-thick sheets of graphene, then created tiny cracks in them with ion beams. When they pulled the cracked material, they found that the cracks expanded rapidly, similar to how a pane of glass would react to a crack.
Steel may not have the overall tensile strength of graphene, but it has a much greater resistance to cracks — so you probably won’t be replacing your steel beams with straight graphene any time soon.
As research continues into this exceptional material, new applications could overcome its limitation. You may be able to buy a smartphone with a graphene screen in coming years…but graphene-based building materials might be a little farther off.