Multilayer graphene with a rippled structure for water desalination

Abstract

In this work, desalination by multilayer graphene membranes with a rippled structure has been considered by molecular dynamics simulation. The (6, 7.5 and 9) Å distances between the graphene sheets in a layer (gap wide) are selected. Also, these mentioned distances are applied as an interlayer space (channel height). Results of simulation demonstrate that multilayer graphene membranes with a rippled structure are more efficient in water flux than multilayer graphene membranes with an unrippled structure. These differences are more significant for membranes with 9 Å interlayer space. In this work, it is shown that water flux in 9 Å rippled membrane is 20% more than 9 Å unrippled one. According to the simulation results, multilayer membranes with a rippled and unrippled structure are different significantly in the case of water flux, but they do not show many differences with each other in rejection. Also, it is shown that the effect of channel is more important than gap; because ions lose more number of water molecules when flow through the channel as compared to flow through gap or pores. From calculation of density, the water flux, ions rejection and coordination number of ions, the results of investigation are obtained.