Breakdown of continuum model for water transport and desalination through ultrathin graphene nanopores: insights from molecular dynamics simulations

Abstract

In the quest for identifying a graphene membrane for efficient water desalination, molecular dynamics simulations were performed for the pressure-driven flow of salty water across a multilayer graphene membrane.

Salt parameterization can drastically affect the results from classical atomistic simulations of water desalination by MoS2 nanopores

“…In recent works about water desalination by nanopores [7,39,40,14,41,42,43] the ion model proposed by Joung and Cheatham [44] has been employed. This model, which will be referred to as NaCl/J, was parameterized based on the hydration free energies of the solvated ions and lattice parameters of salt crystals and has a good agreement with several experimental studies.…”

Scale Effect on Simple Liquid Transport through a Nanoporous Graphene Membrane

“…However, the interaction parameters for identical atoms are tailored for a bulk material system. Calculating the interaction parameters for nonidentical atoms using the L-B mixing rule is an approximation for intermolecular interactions rather than an exact calculation. , Also, more precise mixing rules often necessitate calculating additional parameters such as polarizabilities or ionization potentials in advance. , The L-B mixing rule was used in previous studies to predict the intermolecular interaction between nonidentical atoms. ,, We used the L-B mixing rule for the closest approximation, but the parametric study and the comparison with the experimental results are necessary for further validation. Surface wettability has a significant impact on the flow dynamics and the boundary conditions. , The effect of various interaction strengths with van der Waals forces combining with long-range Coulombic terms and electric field will be investigated in future work.…”

“…55,56 The L-B mixing rule was used in previous studies to predict the intermolecular interaction between nonidentical atoms. 43,57,58 We used the L-B mixing rule for the closest approximation, but the parametric study and the comparison with the experimental results are necessary for further validation. Surface wettability has a significant impact on the flow dynamics and the boundary conditions.…”

Structure and dynamics of a water/methanol mixture confined in zeolitic imidazolate framework ZIF-8 from atomistic simulations

“…To deeply understand the impact of the nanoscopic confinement from ZIF-8 on the pervaporation performance at the atomic scale, the microscopic structure and dynamics of water and alcohols in porous fillers are of considerable interest, given that the guest molecules confined in spaces of nanometer size generally show structural and dynamical properties that deviate substantially from those of the bulk analogue, 37–40 which should in turn affect the effectiveness of the mass transport process in pervaporation and other membrane-based processes. Theoretical investigation is of great help for a better understanding of the properties of a confined fluid.…”