Monte Carlo simulation on the diffusion of polymer in narrow periodical channels

Abstract

Diffusion of polymer in narrow periodical channels, patterned alternately into part [Formula: see text] and part [Formula: see text] with the same length [Formula: see text], was studied by using Monte Carlo simulation. The interaction between polymer and channel [Formula: see text] is purely repulsive, while that between polymer and channel [Formula: see text] is attractive. Results show that the diffusion of polymer is remarkably affected by the periodicity of channel, and the diffusion constant [Formula: see text] changes periodically with the polymer length [Formula: see text]. At the peaks of [Formula: see text], the projected length of polymer along the channel is an even multiple of [Formula: see text], and the diffusion of polymer in periodical channel is nearly the same as that of polymer in homogeneous channel. While at the valleys of [Formula: see text], the projected length of polymer is an odd multiple of [Formula: see text], and polymer is in a trapped state for a long time and it rapidly jumps to other trapped regions during the diffusion process. The physical mechanisms are discussed from the view of polymer–channel interaction energy landscape.