Strain-Tunable Carbon Nanothread-Derived Membranes for Water Desalination

Abstract

Carbon nanothread-derived nanomeshes are highly flexible two-dimensional (2D) structures with tunable pore size and shape, which allows fine control of their transport properties when applied as membranes. In this work, we use molecular dynamics simulations to investigate the performance of several nanomesh structures as membranes for water desalination through reverse osmosis. Results show that these membranes can operate in a wide range of water flow rate, with an optimal point that yields 100% NaCl rejection and water permeability as high as 106 L• cm −2 •day −1 •MPa −1 , higher than other nanoporous 2D materials reported in the literature. This promising performance is partially due to the elliptical pores of strained nanomeshes, which allow the passage of rotated water molecules while rejecting hydrated salt ions. Our results show that carbon nanothread-derived nanomeshes have great potential for application in water desalination processes and emphasize the importance of engineering pore shape in 2D materials when applied as reverse osmosis membranes.

Computational simulation-driven discovery of novel zeolite-like carbon materials as seawater desalination membranes

“…The water flux in standard units of L cm −2 day −1 MPa −1 is calculated from the slope of the N m × t curve with the total membrane area and the exerted pressure normalized in the linear state. 62 With an absolute salt ion rejection assured at 70 MPa, the amount of water permeability is 83.62 L cm −2 day −1 MPa −1 , which is comparable to those of other nanoporous 2D materials according to simulations under similar conditions. 8,63 A reliable desalination membrane should also exhibit a high-efficiency salt ion rejection rate.…”

Accelerating filtration by introducing an oscillation paradigm and its atomistic origin

“…The size of the simulation box in the x – y – z dimensions is 5.7 nm × 6.6 nm × 30.0 nm with the COF membrane located in the x – y plane, and the simulation box contains four parts, including a graphene piston applying pressure to the brine, a COF filter membrane, and brine containing sodium and chloride ions at a molar concentration of 0.5 M, 51–53 slightly lower than the salinity of seawater (∼35 g L −1 ). 54 The lower salinity was chosen because the concentration of water flowing into the pure water region would effectively increase the salinity of the seawater side during the simulation. The synthesis route and structural properties of the COF membrane are shown in Fig.…”

Atomistic Simulations of the Permeability and Dynamic Transportation Characteristics of Diamond Nanochannels

“…The hydration interactions, van der Waal interactions, and electrostatic interactions are the main factors that confine the transition behaviors of aqueous solutions down to nanoscale [ 13 , 14 , 15 , 16 ]. Extensive efforts have been devoted to investigating the characteristics of nanofluids based on experiments [ 17 , 18 , 19 , 20 , 21 ] or theoretical analysis [ 22 , 23 , 24 ], covering different types of synthetic nanochannels [ 24 ], such as carbon nanotubes (CNTs) [ 25 , 26 , 27 , 28 , 29 , 30 , 31 ], nanopores [ 32 , 33 , 34 , 35 ], and functionalized nanopores [ 36 , 37 , 38 , 39 , 40 , 41 ]. Due to their atomically-smooth hydrophobic graphitic surface and nanoscale confinements, sp2 carbon-based nanochannels are the most studied nanofluidic structure.…”