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

Abstract

Through atomistic simulations, this work investigated the permeability of hexagonal diamond nanochannels for NaCl solution. Compared with the multilayer graphene nanochannel (with a nominal channel height of 6.8 Å), the diamond nanochannel exhibited better permeability. The whole transportation process can be divided into three stages: the diffusion stage, the transition stage and the flow stage. Increasing the channel height reduced the transition nominal pressure that distinguishes the diffusion and flow stages, and improved water permeability (with increased water flux but reduced ion retention rate). In comparison, channel length and solution concentration exerted ignorable influence on water permeability of the channel. Further simulations revealed that temperature between 300 and 350 K remarkably increased water permeability, accompanied by continuously decreasing transition nominal pressure. Additional investigations showed that the permeability of the nanochannel could be effectively tailored by surface functionalization. This work provides a comprehensive atomic insight into the transportation process of NaCl solution in a diamond nanochannel, and the established understanding could be beneficial for the design of advanced nanofluidic devices.

An Overview of Mechanical Properties of Diamond-like Phases under Tension

“…The calculations were carried out using the MD simulation as implemented in the LAMMPS simulation package [ 68 , 69 , 70 ], with AIREBO interatomic potential [ 60 ]. The AIREBO parameterization is based on a wide range of experimental data on the properties of carbon structures and hydrocarbons, which allows for a successive use of this potential for a wide variety of issues [ 30 , 67 , 71 , 72 , 73 ]. However, for example, to study different paths for the phase transformations, it is better to use the well-known ReaxFF potential [ 35 , 74 , 75 ].…”

“…The development of the reactive interatomic potentials for carbon [ 58 , 59 , 60 , 61 , 62 , 63 ] adopted molecular dynamics (MD) as one of the most used tools for numerical calculations in this field. Existing MD simulations allow for analyzing the phase transition during synthesis or deformation of carbon phases [ 39 , 64 ], their stability [ 65 ], and their properties in a wide variety of external effects [ 66 , 67 ]. MD simulations can be utilized as a phenomenological method to understand the deformation behavior in materials at the atomistic level.…”

Nanomechanics and Plasticity

“…For instance, there are increasing interests in the synthetic nanochannels (e.g., graphene nanochannels), which possess unique transmission behavior and show appealing prospects for nanofiltration [ 9 , 10 ], water desalination [ 11 , 12 , 13 , 14 ], and energy storage [ 15 , 16 ]. Through atomistic simulations, Li et al [ 17 ] investigated the permeability of a hexagonal diamond nanochannel for a NaCl solution. To facilitate various engineering implementations, a comprehensive understanding of their mechanical properties and deformation mechanisms is usually a prerequisite, which can be acquired through nanoscale experiments and atomistic calculations.…”