The escape transition of a lattice star polymer grafted in a pore

TL;DR

This study models the escape transition of a star polymer grafted in a pore using a lattice self-avoiding walk, revealing arm-by-arm escape behavior and estimating critical points for different lattice geometries.

Contribution

It introduces a numerical lattice model for star polymer escape transitions, providing detailed analysis of arm-specific escape and critical points.

Findings

Arms escape one at a time as pore size decreases

Critical points estimated for square and cubic lattices

Conformational readjustment resembles a thermodynamic phase transition

Abstract

Polymers in confined spaces are compressed and have reduced conformational entropy, and will partially or fully escape from confinement if conditions are suitable. This is in particular the case for a polymer grafted in a pore. The escape of the polymer from the pore may be considered a partial translocation from the pore into bulk solution, and the resulting conformational readjustment of the polymer has characteristics of a thermodynamic phase transition. In this paper a lattice self-avoiding walk model of a star polymer grafted in a pore is examined numerically using the PERM algorithm. We show that the arms of the grafted lattice star escape one at a time as the length of the pore is reduced, consistent with earlier results in the literature. Critical points for the escape transitions are estimated for square and cubic lattice models and we also examine various properties of the model as it undergoes escape transitions.