中国物理B ›› 2017, Vol. 26 ›› Issue (8): 88204-088204.doi: 10.1088/1674-1056/26/8/088204

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

Molecular dynamics simulation of the response of bi-disperse polyelectrolyte brushes to external electric fields

Fen Zhang(张芬), Huan-Da Ding(丁欢达), Chao Duan(段超), Shuang-Liang Zhao(赵双良), Chao-Hui Tong(童朝晖)   

  1. 1 Department of Physics, Ningbo University, Ningbo 315211, China;
    2 College of Chemical Engineering, East China University of Science and Technology, Shanghai 200237, China
  • 收稿日期:2017-03-15 修回日期:2017-04-18 出版日期:2017-08-05 发布日期:2017-08-05
  • 通讯作者: Chao-Hui Tong E-mail:tongchaohui@nbu.edu.cn
  • 基金资助:

    Project supported by the National Natural Science Foundation of China (Grant No. 21374052).

Molecular dynamics simulation of the response of bi-disperse polyelectrolyte brushes to external electric fields

Fen Zhang(张芬)1, Huan-Da Ding(丁欢达)1, Chao Duan(段超)1, Shuang-Liang Zhao(赵双良)2, Chao-Hui Tong(童朝晖)1   

  1. 1 Department of Physics, Ningbo University, Ningbo 315211, China;
    2 College of Chemical Engineering, East China University of Science and Technology, Shanghai 200237, China
  • Received:2017-03-15 Revised:2017-04-18 Online:2017-08-05 Published:2017-08-05
  • Contact: Chao-Hui Tong E-mail:tongchaohui@nbu.edu.cn
  • About author:0.1088/1674-1056/26/8/
  • Supported by:

    Project supported by the National Natural Science Foundation of China (Grant No. 21374052).

摘要:

Langevin dynamics simulations have been performed to investigate the response of bi-disperse and strong polyacid chains grafted on an electrode to electric fields generated by opposite surface charges on the polyelectrolyte (PE)-grafted electrode and a second parallel electrode. Simulation results clearly show that, under a negative external electric field, the longer grafted PE chains are more strongly stretched than the shorter ones in terms of the relative change in their respective brush heights. Whereas under a positive external electric field, the grafted shorter chains collapse more significantly than the longer ones. It was found that, under a positive external electric field, the magnitude of the total electric force acting on one shorter PE chain is larger than that on one longer PE chain, or vice versa. The effects of smeared and discrete charge distributions of grafted PE chains on the response of PE brushes to external electric fields were also examined.

关键词: polyelectrolyte brushes, electric fields, polydispersity, molecular dynamics

Abstract:

Langevin dynamics simulations have been performed to investigate the response of bi-disperse and strong polyacid chains grafted on an electrode to electric fields generated by opposite surface charges on the polyelectrolyte (PE)-grafted electrode and a second parallel electrode. Simulation results clearly show that, under a negative external electric field, the longer grafted PE chains are more strongly stretched than the shorter ones in terms of the relative change in their respective brush heights. Whereas under a positive external electric field, the grafted shorter chains collapse more significantly than the longer ones. It was found that, under a positive external electric field, the magnitude of the total electric force acting on one shorter PE chain is larger than that on one longer PE chain, or vice versa. The effects of smeared and discrete charge distributions of grafted PE chains on the response of PE brushes to external electric fields were also examined.

Key words: polyelectrolyte brushes, electric fields, polydispersity, molecular dynamics

中图分类号:  (Polyelectrolytes)

  • 82.35.Rs
31.15.at (Molecule transport characteristics; molecular dynamics; electronic structure of polymers) 94.20.Ss (Electric fields; current system)