Molecular Dynamics Simulations of Water Anchored in Multi-Layered Nanoporous MoS$_2$ Membranes: Implications for Desalination

TL;DR

This study uses molecular dynamics simulations to analyze water flow through multi-layered MoS2 membranes, revealing unique permeability behaviors and the importance of nanopore architecture for desalination applications.

Contribution

It provides new insights into how nanopore size and structure affect water permeability in MoS2 membranes, challenging classical hydrodynamic expectations.

Findings

Permeability does not scale with membrane thickness as expected.

Water dynamics are slower than in frictionless nanomaterials.

Membrane permeability critically depends on nanopore architecture.

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 necessary task. We studied here, the water flux through multi-layered nanoporous molybdenum disulfide (MLNMoS$_2$) membranes with different nanopore sizes and length. Molecular dynamics simulations show that the permeability do not increase with the inverse of the membrane thickness, violating the classical hydrodynamic behavior. The data also reveals that the water dynamics is slower than that observed in frictionless carbon nanotubes and multi-layer 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.