Continuous graphene film-making process has potential for membranes

Of all the many potential applications for the single-atom-thick form of carbon, graphene, filtration membranes have been one of the most promising but frustratingly elusive. Sheets of graphene should be ideal as the basis for membranes, and researchers have been looking at ways of riddling the sheets with precisely-sized holes to allow only chosen molecules through. The difficulty has been in simply making big enough sheets, as graphene has until now been very difficult to manufacture in large samples. The MIT team, from the Laboratory for Manufacturing Productivity directed by Prof John Hart, has devised the process which could be the basis for production of large sheets on an industrial basis.

Published in a paper in Applied Materials and Interfaces, the research adapts the method commonly used to make graphene film for a more industrial setting. Currently, graphene is often made by chemical vapour deposition, which involves heating up a copper foil and then, under carefully controlled conditions, sending a stream of methane and other gases over it which then grow into sheets of graphene. The new technique also uses copper foil, but it is unwound from a roll and sent into a small furnace through a pair of tubes.