›› 2014, Vol. 23 ›› Issue (11): 118201-118201.doi: 10.1088/1674-1056/23/11/118201

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

Transport of ions through a (6,6) carbon nanotube under electric fields

沈力, 徐震, 周哲玮, 胡国辉   

  1. Shanghai Institute of Applied Mathematics and Mechanics, Shanghai Key Laboratory of Mechanics in Energy Engineering, Shanghai University, Shanghai 200072, China
  • 收稿日期:2014-03-19 修回日期:2014-05-15 出版日期:2014-11-15 发布日期:2014-11-15
  • 基金资助:
    Project supported by the National Natural Science Foundation of China (Grant Nos. 11272197 and 11372175) and the Innovation Program of Shanghai Municipality Education Commission, China (Grant No. 14ZZ095).

Transport of ions through a (6,6) carbon nanotube under electric fields

Shen Li (沈力), Xu Zhen (徐震), Zhou Zhe-Wei (周哲玮), Hu Guo-Hui (胡国辉)   

  1. Shanghai Institute of Applied Mathematics and Mechanics, Shanghai Key Laboratory of Mechanics in Energy Engineering, Shanghai University, Shanghai 200072, China
  • Received:2014-03-19 Revised:2014-05-15 Online:2014-11-15 Published:2014-11-15
  • Contact: Hu Guo-Hui E-mail:ghhu@staff.shu.edu.cn
  • Supported by:
    Project supported by the National Natural Science Foundation of China (Grant Nos. 11272197 and 11372175) and the Innovation Program of Shanghai Municipality Education Commission, China (Grant No. 14ZZ095).

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摘要： The transport of water and ions through carbon nanotubes (CNTs) is crucial in nanotechnology and biotechnology. Previous investigation indicated that the ions can hardly pass through (6,6) CNTs due to their hydrated shells. In the present study, utilizing molecular dynamics simulation, it is shown that the energy barrier mainly originating from the hydrated water molecules could be overcome by applying an electric field large enough in the CNT axis direction. Potential of mean force is calculated to show the reduction of energy barrier when the electric field is present for (Na+, K+, Cl-) ions. Consequently, ionic flux through (6,6) CNTs can be found once the electric field becomes larger than a threshold value. The variation of the coordination numbers of ions at different locations from the bulk to the center of the CNT is also explored to elaborate this dynamic process. The thresholds of the electric field are different for Na+, K+, and Cl- due to their characteristics. This consequence might be potentially applied in ion selectivity in the future.

关键词: nanostructured materials in electrochemistry, carbon nanotube, molecular dynamics, ion exchange

Abstract: The transport of water and ions through carbon nanotubes (CNTs) is crucial in nanotechnology and biotechnology. Previous investigation indicated that the ions can hardly pass through (6,6) CNTs due to their hydrated shells. In the present study, utilizing molecular dynamics simulation, it is shown that the energy barrier mainly originating from the hydrated water molecules could be overcome by applying an electric field large enough in the CNT axis direction. Potential of mean force is calculated to show the reduction of energy barrier when the electric field is present for (Na+, K+, Cl-) ions. Consequently, ionic flux through (6,6) CNTs can be found once the electric field becomes larger than a threshold value. The variation of the coordination numbers of ions at different locations from the bulk to the center of the CNT is also explored to elaborate this dynamic process. The thresholds of the electric field are different for Na+, K+, and Cl- due to their characteristics. This consequence might be potentially applied in ion selectivity in the future.

Key words: nanostructured materials in electrochemistry, carbon nanotube, molecular dynamics, ion exchange

中图分类号:  (Nanostructured materials in electrochemistry)

  • 82.45.Yz
88.30.rh (Carbon nanotubes) 83.10.Mj (Molecular dynamics, Brownian dynamics) 82.39.Wj (Ion exchange, dialysis, osmosis, electro-osmosis, membrane processes)