Molecular Dynamics Simulation of the Desalination of Sea Water by a Forward Osmosis Membrane Containing Charged Carbon Nanotubes

Spurred by traditional membrane science in which a charged membrane can improve separation efficiency, a forward osmosis membrane containing charged "armchair-type" (8, 8) carbon nanotubes (CNTs) was developed and the transport phenomena of water molecules in this membrane were investigated. In the simulation, 0.5 mol . L-1 NaCl was chosen to mimic seawater, and 1 mol . L-1 MgCl2 was chosen as the draw solution. The effects of electric charge on the density distribution, diffusion of water molecules, and the water flux of the membrane were investigated in detail. Modifying the CNT membrane by charge significantly changes the density distribution, diffusion, and flux of water molecules. The membrane containing CNTs modified by -0.3e can achieve the highest water flux of those developed.