Graphene has been receiving a great deal of attention since it was first discovered because of its amazing properties. The atom-thick material has among the highest electrical and thermal conductivity ever measured, while also being incredibly strong and flexible. Now researchers at MIT and Oak Ridge National Laboratory have found imperfections in pristine graphene, but instead of limiting the material's capabilities, this discovery could lead to whole new uses for graphene.
Made of a hexagonal array of carbon atoms, similar to chicken wire, many have believed graphene to be a very impermeable material, but when the researchers tested this they found molecules were slipping right through it. This is because there were apparently microscopic pores in the graphene that were just large enough to allow some molecules through. When put under an electron microscope, the researchers found that the pores were between 1 nm and 12 nm, which is just large enough to let through some molecules, such as some salts, but not larger ones.
The researchers are now looking at how graphene behaves with different substrates and ways to control the shape of the pores. As this represents a way to filter molecules at the molecular level it could lead to advanced sensors and water filtration systems. If these devices are ever realized, the strength of graphene will prove very valuable as the material will not be shredded by materials flowing through it.