An extraordinarily rapid permeation of water through thick GO membranes has been reported by Nair et al. and explained in the light of the capillary pressure effect due to the relatively short inter-layer spacing in their experiments (from 6 to 10 Å). These findings were substantiated using molecular dynamics (MD) simulations. In general, there is a number of MD studies of water transport in GO. Devanathan et al. have calculated the diffusion coefficient of the water intercalated between GO layers. Their work has shown that the 2D channels between GO sheets (with inter-layer spacing ≈ 15 Å) slow down the diffusion of water by an order of magnitude. They attributed this to the strong Hydrogen bonds (HBs) formed between water and the OH groups of GO. In stark contrast with this study, Mouhat et al. have performed ab initio MD simulations using Density Functional Theory (DFT) of hydrated GO (with inter-layer distance around 16 Å) and found that the diffusion of water at the GO/water interface is as fast as in bulk water.