Author(s)

Tong Mou

Corresponding Author

Tong Mou

Abstract

Based on the concept of "root", the mechanism of ion transport in one-dimensional carbon nanotubes is discussed by using molecular dynamics simulation and experimental data. The study revealed that in graphene nanotubes with a diameter of less than 5 nm, the migration rate of cations and anions would decrease as the diameter of the pipe became smaller. In addition, the wall of the negatively charged pipe will trap ions that are different from its electrical properties through electrostatic attraction, further slowing down the migration rate of these ions. Under the superposition of these two factors, we observed that the migration rate of sodium ion first accelerated with the increase of the wall charge density, and then slowed down, while the migration rate of chloride ion showed the opposite trend. This study deepens our understanding of the abnormal conduction phenomena in low-dimensional carbon nanotubes and provides a theoretical basis for designing the structures of such nanotubes. In addition, the research has a vital role in the innovation and development of membrane material technology, and can also play a prominent role in the field of seawater desalination.

Keywords

Molecular dynamics; Nanochannel; Ion transport; Ion selectivity