Thermodynamics of polymer adsorption to a flexible membrane

TL;DR

This study investigates how a single polymer interacts with a flexible membrane, revealing complex phase behaviors and new conformational phenomena due to membrane flexibility, using advanced Monte Carlo simulations.

Contribution

It introduces a detailed model of polymer-membrane interactions and uncovers novel behaviors caused by membrane flexibility, expanding understanding beyond stiff surface adsorption.

Findings

Rich phase diagram with ordered and extended structures

Membrane flexibility leads to unique stretching behaviors

Identification of conformational transitions as a function of parameters

Abstract

We analyze the structural behavior of a single polymer chain grafted to an attractive, flexible surface. Our model is composed of a coarse-grained bead-and-spring polymer and a tethered membrane. By means of extensive parallel tempering Monte Carlo simulations it is shown that the system exhibits a rich phase behavior ranging from highly ordered, compact to extended random coil structures and from desorbed to completely adsorbed or even partially embedded conformations. These findings are summarized in a pseudophase diagram indicating the predominant class of conformations as a function of the external parameters temperature and polymer-membrane interaction strength. By comparison with adsorption to a stiff membrane surface it is shown that the flexibility of the membrane gives rise to qualitatively new behavior such as stretching of adsorbed conformations.