title: Abnormal polymer transport in crowded attractive micropost arrays.
abstract: We investigate polymer diffusion in a quasi-two-dimensional environment decorated with attractive cylindrical posts using Langevin dynamics simulation. We find that the polymer diffusivity has non-monotonic dependence on the post array density. This diffusive behavior strongly depends on the adsorption-desorption transition and the critical adsorption strength εc. For ε < εc, the polymer undergoes normal diffusion and the diffusivity decreases as the post density increases due to the reduction of the void volume. For ε > εc, polymer dynamics is strongly mediated by post adsorption, and we observe a regime where the polymer diffusivity increases as the post density increases. The polymer diffusivity reaches a maximum, which can be attributed to cross-post translation enabled by large polymer conformation fluctuations. We find both cross-post transport and polymer conformation fluctuations strongly depend on the post absorption strength and the chain length.
authors.affiliation: Department of Physics, National Taiwan University, Taipei, Taiwan and Institute of Physics, Academia Sinica, Taipei, Taiwan.
authors.forename: Wei
authors.initials: W
authors.lastname: Chien
authors.affiliation: Department of Physics, National Taiwan University, Taipei, Taiwan and Institute of Physics, Academia Sinica, Taipei, Taiwan and Department of Chemical Engineering, National Tsing-Hua University, Hsinchu, Taiwan. ylchen@gate.sinica.edu.tw.
authors.forename: Yeng-Long
authors.initials: YL
authors.lastname: Chen