Permeability Analysis of Pure Water across Nano Porous Graphene

Being the thinnest and strongest material, graphene has tremendous potential for water desalination. This paper reports the analysis of water permeability across single layer free standing nano porous graphene. Using classical molecular dynamics simulation, it has been found that the permeability of water through graphene is depended on its pore diameter. However, surprisingly there exists a minimum threshold of pore diameter for the water molecules to pass, which is nearly two times larger than the diameter of the water molecule. Investigation using simulation found that that threshold pore diameter is around 6 A, whereas the molecular diameter of water is only 2.75 A. In addition, an increment in pore diameter decreases reverse osmotic pressure. This work increases maturity and reliability of pure water permeability analysis across nano porous graphene for desalination.