REPTATION, ENTROPIC TRAPPING, PERCOLATION, AND ROUSE DYNAMICS OF POLYMERS IN RANDOM-ENVIRONMENTS

We study the dynamics of polymers in 2D periodic arrays of obstacles where a fraction (1-c) of the obstacles have been removed. As expected, we find Rouse and reptation dynamics for c→0 and c→1, respectively. However, we also find that the diffusion coefficient D decreases when we start removing obstacles due to entropic trapping of the polymer within "pores." These pores begin to form large clusters when c0.80, and D increases when c is decreased further. Our results clarify the nature of the different regimes for a simple random environment and predict that D(c) can be a nonmonotonic function of c. © 1995 The American Physical Society.