Temperature dependence of the translocation time of polymer through repulsive nanopores

摘要

The forced translocation of a polymer chain through repulsive nanopores was studied by using Langevin dynamics simulations. The polymer is in the compact globule state at low temperature and in the random coil state at high temperature. Simulation results show that the mean translocation time is highly dependent on the temperature T and the minimal i is located near the coil- globule transition temperature. Moreover, the scaling behaviors similar to N-alpha and similar to F-delta are studied, with N the polymer length and F the driving force inside the nanopore. Universal values alpha = 1.4 and delta = 0.85 are observed for the polymer in the random coil state. While for the polymer in the compact globule state, ff decreases from alpha = 2 at weak driving to 1.2 at strong driving for short N and delta increases with decreasing T in the low F region, but we find universal exponents alpha = 1.6 for long N and delta = 0.85 in the large F region. Results show that polymer's conformation plays a much more important role than the diffusion coefficient in controlling the translocation time of the polymer chain. Published by AIP Publishing.