It has previously been difficult to manufacture graphene-based barriers on an industrial scale as a single layer of carbon atoms arranged in a hexagonal lattice, but the scientists found solution using instead graphene oxide which can be produced by simple oxidation in the lab. The membrane must have a very uniform less-than-one-nanometre hole size to make it useful for desalination. Dr Nair and colleagues created a stable membrane placing walls made of epoxy resin (a substance used in coatings and glues) on either side of the graphene oxide. The tiny capillaries of the graphene-oxide membranes block the salt from water. “Water molecules can go through individually, but sodium chloride cannot. It always needs the help of the water molecules. The size of the shell of water around the salt is larger than the channel size, so it cannot go through,” explained Dr Nair. Producing inexpensive membranes for desalination was a goal and is possible this solution to be the answer.