Another amazing characteristic of graphene, the wonder material has been discovered by scientists from the University of Manchester. They found that it is superpermeable in relation with water.
Graphene-based membrane
Graphene, an amazing material, has the potential to design wallpaper-thin lighting panels, foldaway mobile phones and sophisticated aircraft. This discovery of its superpermeability suggests that it can be used in the distillation of alcohol.
Professor Sir Andre Geim led the research team and demonstrated that membranes based on graphene do not permeate all vacuum-tight liquids and gases but water permeates in such a way that it seems as if the membrane was not present at all.
This amazing property can be added to its long list of excellent properties, which include its high strength, minimum thickness and superior thermal and electrical conductivity. It is very stiff as well as ductile.
Presently, scientists from the University of Manchester have analyzed membranes from graphene oxide, a chemical derivative of graphene. Graphene oxide is graphene covered with hydroxyl groups. A laminate is formed by stacking graphene oxide sheets atop each other. These laminates have a thickness, hundred times lesser than that of a human hair, yet is flexible, robust and easy to handle.
The sealing of a metal container with the laminate ensured that no gas or liquid leaked through. However, water evaporated irrespective of the seal. The speed at which water molecules diffused was tremendous that the rate of evaporation did not change whether the container was opened or sealed.
Dr Rahul Nair stated that graphene oxide sheets align such that there is room for just one water molecule layer. They align themselves into ice sheets one molecule thick that slide without any friction along the surface of graphene. Normally helium gas leaks even through 1 mm thick window glass but these ultra-thin films block it totally. However, water evaporates without any obstruction. Graphene is truly strange in its behavior and researchers wonder what other amazing property it has, which is yet to be discovered.
According to another researcher, Dr Irina Grigorieva, this amazing characteristic of graphene can be used in cases where water alone has to be removed and all other ingredients be retained.
Source: http://www.manchester.ac.uk