Molecular Dynamics Simulations of Water Anchored in Multilayered Nanoporous MoS₂ Membranes: Implications for Desalination

Abstract

One of the most promising applications in nanoscience is the design of new materials to improve water permeability and selectivity of nanoporous membranes. Understanding the molecular architecture behind these fascinating structures and how it impacts the water flow is an intricate but a necessary task. We studied here the water flux through multilayered nanoporous molybdenum disulfide (MLNMoS 2 ) membranes with different nanopore sizes and lengths. Molecular dynamics simulations show that the permeability does not increase with the inverse of the membrane thickness, violating the classical hydrodynamic behavior. The data also reveal that water dynamics is slower than those observed in frictionless carbon nanotubes and multilayer graphene membranes, which we explain in terms of an anchor mechanism observed in between layers. We show that the membrane permeability is critically dependent on the nanopore architecture, bringing important insights into the manufacture of new desalination membranes.

Towards the realisation of high permi-selective MoS2 membrane for water desalination

“…The surface energies prevent water from flowing into the transport channels and would need significant overpressures to wet the surface 108 . As demonstrated in some studies, permeability does not scale with the inverse of the membrane thickness, contrary to the conventional hydrodynamic behaviour 64,110 . The nanopore design has a significant impact on membrane permeability, revealing valuable information on how future desalination membranes should be made.…”

Single-layer membranes for organic solvent nanofiltration: a molecular dynamics simulation and comparative experimental study

“…Abal et al nd that a nonmonotonic dependence of the water ux and water permeance on the thickness of membranes. [40][41][42][43] The relationship between the permeability and solvent properties is showed as eqn (5). 44 P S f d s m s d m;s 2 (5) where d s , m s and m,s are the solubility parameter, viscosity and diameter of solvent, respectively, as showed in Table S1.…”

Atmospheric water harvesting using functionalized carbon nanocones

“…The lack of potable water results from a number of factors such as monoculture, increasing deforestation, and a growing population [2][3][4][5]. In order to circumvent the problem of lack of fresh water, scientists are developing alternative processes such as filtration of contaminated water [6], desalinization [7], and the collection of water from the atmosphere [8]. Atmospheric water harvesting (AWH) is an interesting option to obtain fresh water, particularly in arid and semi-arid areas, where other sources of water are inaccessible, and populations have long been suffering from water scarcity [9].…”