SCI和EI收录∣中国化工学会会刊

Chin.J.Chem.Eng. ›› 2012, Vol. 20 ›› Issue (2): 231-238.

• FLUID DYNAMICS AND TRANSPORT PHENOMENA • Previous Articles     Next Articles

Translocation of Polymer Through a Nanopore Studied by Langevin Dynamics:Effect of the Friction Coefficient

FENG Jian1, SHANG Yazhuo2, ZHOU Lihui2, LIU Honglai2, HU Ying2   

  1. 1. Department of Applied Chemistry, Chuzhou University, Anhui 239012, China;
    2. State Key Laboratory of Chemical Engineering and Department of Chemistry, East China University of Science and Technology, Shanghai 200237, China
  • Received:2011-03-19 Revised:2011-06-03 Online:2012-05-02 Published:2012-04-28
  • Supported by:
    Supported by the National Natural Science Foundation of China (20736002, 20706013);the Open Project of the State Key Laboratory of Chemical Engineering ECUST (SKL-ChE-09C02);the Natural Science Fund of the Education Department of Anhui Province (KJ2011B116)

Translocation of Polymer Through a Nanopore Studied by Langevin Dynamics:Effect of the Friction Coefficient

冯剑1, 尚亚卓2, 周丽绘2, 刘洪来2, 胡英2   

  1. 1. Department of Applied Chemistry, Chuzhou University, Anhui 239012, China;
    2. State Key Laboratory of Chemical Engineering and Department of Chemistry, East China University of Science and Technology, Shanghai 200237, China
  • 通讯作者: LIU Honglai
  • 基金资助:
    Supported by the National Natural Science Foundation of China (20736002, 20706013);the Open Project of the State Key Laboratory of Chemical Engineering ECUST (SKL-ChE-09C02);the Natural Science Fund of the Education Department of Anhui Province (KJ2011B116)

Abstract: The driven polymer translocation through a nanopore with unbiased initial configuration has been studied by using Langevin dynamics(LD) simulations.It is found that the scaling relationship between translocation time and the polymer chain length is strongly affected by the friction coefficient in LD and the driving force.However,there is no scaling relationship between the translocation time and the friction coefficient.The translocation time is almost inversely proportional to the driving force,which is in agreement with those obtained in biased translocation.The scaling relationship between gyration radius(Rg) of subchain at the trans side with the subchain length (L) is RgL0.33 that is in good agreement with the limiting value for molten globule state,while the curve of Rg of subchain at the cis side has two distinct stages.During translocation,the subchain at the cis side is being stretched gradually,and the structure of the subchain transforms from sphere-like to rod-like.When the effect of stretching reaches the tail end,the subchain is at the most stretched state.Finally the subchain will rapidly restore to coil structure.According to the results of force analysis,the retarding force at the trans side is more crucial during the practical translocation.

Key words: translocation, Langevin dynamics, friction coefficient, polymer, nanopore

摘要: The driven polymer translocation through a nanopore with unbiased initial configuration has been studied by using Langevin dynamics(LD) simulations.It is found that the scaling relationship between translocation time and the polymer chain length is strongly affected by the friction coefficient in LD and the driving force.However,there is no scaling relationship between the translocation time and the friction coefficient.The translocation time is almost inversely proportional to the driving force,which is in agreement with those obtained in biased translocation.The scaling relationship between gyration radius(Rg) of subchain at the trans side with the subchain length (L) is RgL0.33 that is in good agreement with the limiting value for molten globule state,while the curve of Rg of subchain at the cis side has two distinct stages.During translocation,the subchain at the cis side is being stretched gradually,and the structure of the subchain transforms from sphere-like to rod-like.When the effect of stretching reaches the tail end,the subchain is at the most stretched state.Finally the subchain will rapidly restore to coil structure.According to the results of force analysis,the retarding force at the trans side is more crucial during the practical translocation.

关键词: translocation, Langevin dynamics, friction coefficient, polymer, nanopore