Molecular dynamics simulation of transport characteristics of water molecules through high aspect ratio hourglass-shaped pore

This research utilizes molecular dynamics (MD) simulations in order to study the effect of the length on water transport properties through the pore with an hourglass shape structure. While the narrowest section of the pore is kept constant, the length of the pore is increased in the range of 100-200 angstrom. The narrowest section allows water molecules to cross just in single-file configuration. It observed that flow decreases as the length increases unlike the water flux which increases with length, which attributes to the frictionless surface of the pore. In comparable with flux, the efficiency increases as the length increases. The increase of the diffusion coefficient and permeability together suggest that the entrance effect can be negligible as the length increases. It revealed that the friction force decreases with increasing the length. On the other hand, the displacement of water molecules from wall increases with length. These results together suggest that as the length increases the wall surface becomes frictionless. (C) 2016 Published by Elsevier B.V.