Simulation study on the translocation of diblock copolymer AnBn through interacting nanopores

Translocation of diblock copolymer A(n)B(n) through an interacting nanopore is studied using a dynamic Monte Carlo method on a simple three-dimensional cubic lattice. The probabilities and translocation times of two translocation orientations of copolymer, orientation A with block A translocating first and orientation B with block B first, are mainly dependent on the segment-pore interactions ε(A) and ε(B). We find that both the probability and the translocation time are larger for the orientation with stronger attraction. The dynamic behaviors of copolymer translocation at different ε(A) and ε(B) can be explained based on the free energy landscapes of homopolymer at different polymer-pore interaction. The results reveal a complicated free energy landscape for copolymer translocation.