Water desalination using graphene nanopores: Influence of the water models used in simulations

Molecular dynamics simulations are widely employed to analyze water and ion permeation through nanoporous membranes for reverse osmosis applications. In such simulations, water models play an important role in accurately reproducing the properties of water. We investigated the water and ion transport across a hydroxyl (OH) functionalized graphene nanopore using six water models: SPC, SPC/E, SPC/Fw, TIP3P, TIP4P, and TIP4P/2005. The water flux thus obtained varied up to 84% between the models. The water and ion flux showed a correlation with the bulk transport properties of the models such as the diffusion coefficient and shear viscosity. We found that the hydrogen-bond lifetime, resulting from the partial charges of the model, influenced the flux. Our results are useful in the selection of a water model for computer simulations of desalination using nanomembranes. Our findings also suggest that lowering the hydrogen-bond lifetime and enhancing the rate of diffusion of water would lead to enhanced water/ion flux.Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Process and Energ

The effect of water models on desalination through graphene nanopores

Nanoporous carbon materials are extensively studied for various separation applications. Among them, water desalination by means of Reverse Osmosis (RO) stands out due to it's large socio-economic relevance. Many studies are carried out in this area both computationally and experimentally. In computational studies the water simulated using different water models are prone to produce inconsistent results. In this study water desalination through hydrogen functionalized graphene nanopore is studied using different water models (SPC, SPC/E, TIP3P, TIP4P/2005). Up to 81% difference was observed in the flux estimates among the models. The water permeation rate was found to be closely related to the bulk transport properties of the simulated water.Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Complex Fluid Processin