Bistable collective behavior of polymers tethered in a nanopore

TL;DR

This study investigates the collective behavior of tethered polymers in nanopores, revealing two stable phases influenced by interpolymer interactions, which could regulate transport mechanisms in biological and nanotechnological systems.

Contribution

The paper combines Monte Carlo and Density Functional Theory methods to identify and analyze phase behavior of polymers in nanopores, highlighting a potential mechanism for pore opening and closing.

Findings

Two distinct polymer phases identified: wall-condensed and centrally condensed.

Phase stability depends on interpolymer interactions.

Possible regulation of pore transport via interaction-induced phase transitions.

Abstract

Polymer-coated pores play a crucial role in nucleo-cytoplasmic transport and in a number of biomimetic and nanotechnological applications. Here we present Monte Carlo and Density Functional Theory approaches to identify different collective phases of end-grafted polymers in a nanopore and to study their relative stability as a function of intermolecular interactions. Over a range of system parameters that is relevant for nuclear pore complexes, we observe two distinct phases: one with the bulk of the polymers condensed at the wall of the pore, and the other with the polymers condensed along its central axis. The relative stability of these two phases depends on the interpolymer interactions. The existence of the two phases suggests a transport mechanism in which marginal changes in these interactions, possibly induced by nuclear transport receptors, cause the pore to transform between open and closed configurations.