中国物理B ›› 2018, Vol. 27 ›› Issue (9): 98801-098801.doi: 10.1088/1674-1056/27/9/098801

• INTERDISCIPLINARY PHYSICS AND RELATED AREAS OF SCIENCE AND TECHNOLOGY • 上一篇    下一篇

Potentials of classical force fields for interactions between Na+ and carbon nanotubes

De-Yuan Li(李德远), Guo-Sheng Shi(石国升), Feng Hong(洪峰), Hai-Ping Fang(方海平)   

  1. 1 Department of Physics and Shanghai Applied Radiation Institute, Shanghai University, Shanghai 200444, China;
    2 Division of Interfacial Water and Key Laboratory of Interfacial Physics and Technology, Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800, China
  • 收稿日期:2018-05-11 修回日期:2018-06-07 出版日期:2018-09-05 发布日期:2018-09-05
  • 通讯作者: Guo-Sheng Shi, Feng Hong E-mail:gsshi@shu.edu.cn;fenghong@shu.edu.cn
  • 基金资助:
    Project supported by the National Science Fund for Outstanding Young Scholars of China (Grant No. 11722548) and the National Natural Science Foundation of China (Grant Nos. 11574339 and 11404361).

Potentials of classical force fields for interactions between Na+ and carbon nanotubes

De-Yuan Li(李德远)1,2, Guo-Sheng Shi(石国升)1,2, Feng Hong(洪峰)1, Hai-Ping Fang(方海平)1,2   

  1. 1 Department of Physics and Shanghai Applied Radiation Institute, Shanghai University, Shanghai 200444, China;
    2 Division of Interfacial Water and Key Laboratory of Interfacial Physics and Technology, Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800, China
  • Received:2018-05-11 Revised:2018-06-07 Online:2018-09-05 Published:2018-09-05
  • Contact: Guo-Sheng Shi, Feng Hong E-mail:gsshi@shu.edu.cn;fenghong@shu.edu.cn
  • Supported by:
    Project supported by the National Science Fund for Outstanding Young Scholars of China (Grant No. 11722548) and the National Natural Science Foundation of China (Grant Nos. 11574339 and 11404361).

摘要:

Carbon nanotubes (CNTs) have long been expected to be excellent nanochannels for use in desalination membranes and other bio-inspired human-made channels owing to their experimentally confirmed ultrafast water flow and theoretically predicted ion rejection. The correct classical force field potential for the interactions between cations and CNTs plays a crucial role in understanding the transport behaviors of ions near and inside the CNT, which is key to these expectations. Here, using density functional theory calculations, we provide classical force field potentials for the interactions of Na+/hydrated Na+ with (7,7), (8,8), (9,9), and (10,10)-type CNTs. These potentials can be directly used in current popular classical software such as nanoscale molecular dynamics (NAMD) by employing the tclBC interface. By incorporating the potential of hydrated cation-π interactions to classical all-atom force fields, we show that the ions will move inside the CNT and accumulate, which will block the water flow in wide CNTs. This blockage of water flow in wide CNTs is consistent with recent experimental observations. These results will be helpful for the understanding and design of desalination membranes, new types of nanofluidic channels, nanosensors, and nanoreactors based on CNT platforms.

关键词: carbon nanotube, density functional theory, force field, molecular dynamics simulation

Abstract:

Carbon nanotubes (CNTs) have long been expected to be excellent nanochannels for use in desalination membranes and other bio-inspired human-made channels owing to their experimentally confirmed ultrafast water flow and theoretically predicted ion rejection. The correct classical force field potential for the interactions between cations and CNTs plays a crucial role in understanding the transport behaviors of ions near and inside the CNT, which is key to these expectations. Here, using density functional theory calculations, we provide classical force field potentials for the interactions of Na+/hydrated Na+ with (7,7), (8,8), (9,9), and (10,10)-type CNTs. These potentials can be directly used in current popular classical software such as nanoscale molecular dynamics (NAMD) by employing the tclBC interface. By incorporating the potential of hydrated cation-π interactions to classical all-atom force fields, we show that the ions will move inside the CNT and accumulate, which will block the water flow in wide CNTs. This blockage of water flow in wide CNTs is consistent with recent experimental observations. These results will be helpful for the understanding and design of desalination membranes, new types of nanofluidic channels, nanosensors, and nanoreactors based on CNT platforms.

Key words: carbon nanotube, density functional theory, force field, molecular dynamics simulation

中图分类号:  (Carbon nanotubes)

  • 88.30.rh
31.15.E (Density-functional theory) 87.10.Tf (Molecular dynamics simulation)