Solvated Polymer Translocation Under Confinement Using an Entropic Barrier Model

In this study, we probe the effect of polymer-surface interactions on the kinetics of confined polymer translocation through an entropic barrier between two cavities and investigate how this effect varies with solvent quality (excluded volume interactions) and confinement. The free energy landscape within the cavities is obtained by self-consistent field theory (SCFT) calculations, and these free energies are used to determine the mean translocation time of polymer from one cavity to another. It is found that the mean translocation time is strongly dependent on the strength of the polymer-surface interactions and shows a non-monotonic dependence with interaction strength. Two competing factors contribute to the non-monotonicity: the excluded volume effect and the polymer-surface interaction strength. Kinetics initially get faster with increasing polymer-surface interactions, but eventually slow down as interactions become strong enough for adsorption to occur. As excluded volume increases, this transition into slower kinetics shifts toward stronger interactions. Furthermore, when translocation occurs between cavities of different sizes, the behavior is monotonic, with smaller cavities becoming more favorable at higher interaction strengths.