Graphene water filter turns whisky clear

Previously graphene-oxide membranes were shown to be completely impermeable to all solvents except for water. However, a study published in Nature Materials, now shows that we can tailor the molecules that pass through these membranes by simply making them ultrathin.

The research team led by Professor Rahul Nair at the National Graphene Institute and School of Chemical Engineering and Analytical Science at The University of Manchester tailored this membrane to allow all solvents to pass through but without compromisingit's ability to sieve out the smallest of particles.

In the newly developed ultrathin membranes, graphene-oxide sheets are assembled in such a way that pinholes formed during the assembly are interconnected by graphene nanochannels, which produces an atomic-scale sieve allowing the large flow of solvents through the membrane.

This new research allows for expansion in the applications ofgraphene based membranes from sea water desalination to organic solvent nanofiltration (OSN). Unlike sea water desalination, which separate salts from water, OSN technology separates charged or uncharged organic compounds from an organic solvent.