Effect of grafting on the binding transition of two flexible polymers

TL;DR

This study explores how grafting two flexible polymers to a surface changes their binding transition from discontinuous to continuous, supported by simulation analyses and entropy considerations.

Contribution

It demonstrates that grafting alters the transition order of polymer binding, a novel insight into polymer-surface interactions.

Findings

Grafting converts a discontinuous transition into a continuous one.

Simulation results support the change in transition order due to grafting.

Reduced translational entropy explains the transition change.

Abstract

We investigate the binding transition of two flexible polymers grafted to a steric surface with closeby end points. While free polymers show a discontinuous transition, grafting to a steric flat surface leads to a continuous binding transition. This is supported by results from Metropolis and parallel multicanonical simulations. A combination of canonical and microcanonical analyses reveals that the change in transition order can be understood in terms of the reduced translational entropy of the unbound high-temperature phase upon grafting.