Department of Physics, Zhejiang University, Hangzhou 310027, China.
J Chem Phys. 2011 Nov 7;135(17):174901. doi: 10.1063/1.3658047.
The effect of crowded environment with static obstacles on the translocation of a three-dimensional self-avoiding polymer through a small pore is studied using dynamic Monte Carlo simulation. The translocation time τ is dependent on polymer-obstacle interaction and obstacle concentration. The influence of obstacles on the polymer translocation is explained qualitatively by the free energy landscape. There exists a special polymer-obstacle interaction at which the translocation time is roughly independent of the obstacle concentration at low obstacle concentration, and the strength of the special interaction is roughly independent of chain length N. Scaling relation τ ~ N(1.25) is observed for strong driving translocations. The diffusion property of polymer chain is also influenced by obstacles. Normal diffusion is only observed in dilute solution without obstacles or in a crowded environment with weak polymer-obstacle attraction. Otherwise, subdiffusion behavior of polymer is observed.
使用动态蒙特卡罗模拟研究了具有静态障碍物的拥挤环境对三维自回避聚合物通过小孔迁移的影响。迁移时间 τ 取决于聚合物-障碍物相互作用和障碍物浓度。障碍物对聚合物迁移的影响通过自由能景观定性解释。在特殊的聚合物-障碍物相互作用下，在低障碍物浓度下，迁移时间大致与障碍物浓度无关，并且特殊相互作用的强度大致与链长 N 无关。对于强驱动力的迁移，观察到 τ~N(1.25)的标度关系。障碍物也会影响聚合物链的扩散性质。在没有障碍物的稀溶液或在聚合物-障碍物吸引力较弱的拥挤环境中，仅观察到正常扩散。否则，观察到聚合物的亚扩散行为。
