A coating so thin it is invisible to the human eye has been shown to make copper nearly 100 times more resistant to corrosion, creating potential for metal protection even in harsh environments.

In a paper published in the September issue of Carbon, researchers from Monash University and Rice University say their findings could mean changes in the development of anti-corrosion coatings using extremely thin graphene films. Graphene is a microscopically thin layer of carbon atoms. It is already in use in such things as smartphone screens, and it is attracting research attention for its possibilities as a means of increasing metal’s resistance to corrosion.

According to Dr. Parama Banerjee, who performed most of the experiments for the study, graphene exhibits good mechanical properties. For instance, the polymer coatings often used on metals can be scratched, compromising their protective ability. But the invisible layer of graphene — although it changes neither the feel nor the appearance of the metal — is much harder to damage.

The researchers applied the graphene to copper at temperatures between ~1,470 and 1,650°F (800 and 900°C) using chemical vapor deposition, and tested it in saline water. Initial experiments were confined to copper, but Dr. Banerjee said research was already under way on using the same technique with other metals.

According to researchers, graphene could be used in applications where metal is used and at risk for corrosion.