Carbon nanotube arrays as monolayer nanoscale membrane for enhanced desalination

Carbon nanotubes (CNTs) have attracted considerable attention due to their extraordinary properties, which makes them very attractive in various applications such as desalination. The single-layer parallel arranged carbon nanotubes (SPACNTs) can form slits that allow water to pass along the outer wall of the CNTs while blocking salt ions. In this work, the water flow rate and desalination of SPACNTs were studied. Through molecular dynamics simulations, the filtration efficiency of water and ions in channels with varying radius (from 0.5 to 3.0 nm) of CNTs and slit size (from 0.7 to 1.5 nm) was studied. When the slit between CNTs is 0.7 nm with a 3 nm radius, the maximum water flow rate of 1,200 L/(m2 h bar) and the salt rejection close to 100% are shown. This work provides some theoretical guidance for the study of CNT membranes for desalination. Keywords: Carbon nanotubes; Desalination; Water permeability; Molecular dynamics