Water desalination through armchair carbon nanotubes: a molecular dynamics study

Abstract

In this paper, molecular dynamics simulations were performed to study desalination performance of armchair carbon nanotubes (CNTs). The studied systems included the (7, 7) and (8, 8) CNTs embedded in a silicon nitride membrane immersed in an aqueous ionic solution. For desalinating water, an external electrical field was applied to the systems along the axis of nanotubes. The results indicated that the (7, 7) and (8, 8) CNTs were exclusively selective to ions. The (7, 7) CNT selectively separated sodium ions from aqueous solution. In contrast, the (8, 8) CNT selectively separated chlorine ions. CNTs ion selectivity is justified by calculating the potential of mean force for each ion in the related system. Also, the results were confirmed using the following simulated properties: ion current, retention time of ions, transport rate for water molecules, the average density of water inside the CNTs, and the radial distribution functions of ions-water. Based on the findings of this study, the studied systems can be recommended as a model for the desalination of water.

Removal of heavy metals from water through armchair carbon and boron nitride nanotubes: a computer simulation study

“…The center of the nanotubes was set as the center of the simulation box. [45][46][47][48] The TIP3P water model was used to represent water molecules. The axes of the nanotubes were parallel to the z-axis of the box, and an electric eld was applied in the z direction of the system.…”

Removal of a hazardous heavy metal from aqueous solution using functionalized graphene and boron nitride nanosheets: Insights from simulations

“…The particle mesh Ewald method [42] was used to treat the long-range electrostatic interactions. In this research, as in previous works [43][44][45][46][47][48], all analyses were performed using VMD 1.9.2 software [49].…”

Removal of trihalomethanes from aqueous solution through armchair carbon nanotubes: A molecular dynamics study

“…The water-CNT, water-THMs and THMs-CNT interaction parameters were derived using the Lorentz-Berthelot combining rules. We performed MD simulations with NAMD2.9 [33] similar to previous works [34][35][36][37] with a 1 fs time step using a Particle Mesh Ewald (PME) summation for electrostatic interactions calculations [38]. Also, all analysis scripts were composed locally using the VMD1.9.2 [39] and Tcl commands.…”