From an article by Dawn Levy at phys.org:
Researchers at Penn State, the Department of Energy’s Oak Ridge National Laboratory and Lockheed Martin Space Systems Company have developed methods to control defects in two-dimensional materials, such as graphene, that may lead to improved membranes for water desalination, energy storage, sensing or advanced protective coatings.
For a two-dimensional, one-atom-thick material like graphene, defects such as small cracks or holes can make a big difference in performance. Usually, these defects are considered undesirable. But if the defects can be controlled, they can be used to engineer new, desirable properties into the material.
“As long as you can control defects, you might be able to synthesize in whatever response the graphene will give you,” says Adri van Duin, corresponding author on a recent paper in the American Chemical Society’s journal ACS Nano. “But that does require that you have very good control over defect structure and defect behavior. What we have done here is a pretty strong step towards that.”