Exact results for the adsorption of a semiflexible copolymer chain in three dimensions

TL;DR

This paper analytically investigates the adsorption-desorption phase transition of a semiflexible copolymer chain on a surface using a lattice directed self-avoiding walk model, revealing how stiffness influences transition points.

Contribution

It provides exact analytical results for the adsorption transition points of semiflexible copolymer chains with different surface interactions, extending understanding of polymer-surface interactions.

Findings

Stiffer copolymer chains adsorb at lower surface attraction strengths.

Adsorption behavior of copolymers resembles that of semiflexible homopolymers.

Exact transition points are determined for various interaction cases.

Abstract

Lattice model of directed self avoiding walk has been solved analytically to investigate adsorption desorption phase transition behaviour of a semiflexible sequential copolymer chain on a two dimensional impenetrable surface perpendicular to the preferred direction of the walk of the copolymer chain in three dimensions. The stiffness of the chain has been accounted by introducing an energy barrier for each bend in the walk of the copolymer chain. Exact value of adsorption desorption transition points have been determined using generating function method for the cases in which one type of monomer is having interaction with the surface viz., (i) no interaction (ii) attractive interaction and (iii) repulsive interaction. Results obtained in each of the case show that for stiffer copolymer chain adsorption transition occurs at a smaller value of monomer surface attraction than a flexible copolymer chain. These features are similar to that of a semi-flexible homopolymer chain adsorption.