Pulling adsorbed polymers from surfaces with the AFM: stick versus slip, peeling versus gliding

TL;DR

This paper models the mechanical response of adsorbed polymers pulled by an AFM, distinguishing between peeling and gliding behaviors based on surface friction and adsorption strength, to interpret force-spectroscopic data.

Contribution

It introduces a simple geometric framework to differentiate between peeling and slipping of polymers under AFM pulling, linking force profiles to surface properties.

Findings

Force profiles depend on friction coefficient and adsorption strength.

Method enables extraction of surface friction and adhesion parameters from data.

Distinguishes peeling from slipping behavior in polymer-surface interactions.

Abstract

We consider the response of an adsorbed polymer that is pulled by an AFM within a simple geometric framework. We separately consider the cases of i) fixed polymer-surface contact point, ii) sticky case where the polymer is peeled off from the substrate, and iii) slippery case where the polymer glides over the surface. The resultant behavior depends on the value of the surface friction coefficient and the adsorption strength. Our resultant force profiles in principle allow to extract both from non-equilibrium force-spectroscopic data.