Control over water friction with 2D materials points to 'smart membranes': Dramatic decrease in friction when water is passed through nanoscale capillaries made of graphene

The speed of water flow is a limiting factor in many membrane-based industrial processes, including desalination, molecular separation and osmotic power generation. Researchers have revealed a dramatic decrease in friction when water is passed through nanoscale capillaries made of graphene. In contrast, capillaries made from hexagonal boron nitride (hBN) - which has a similar surface topography and crystal structure as graphene - display high friction.