Irreversibility and Polymer Adsorption

TL;DR

This paper develops a theoretical model for irreversible polymer adsorption layers, revealing a layered structure with a broad distribution of surface contacts that aligns with experimental observations.

Contribution

It introduces a non-equilibrium theory for polymer adsorption layers, highlighting the layered structure and contact distribution in irreversible adsorption.

Findings

Density profile matches equilibrium layers

Contact fraction distribution P(f) ~ f^{-4/5}

Layer structure includes a tightly bound core and outer chains

Abstract

Physisorption or chemisorption from dilute polymer solutions often entails irreversible polymer-surface bonding. We present a theory of the non-equilibrium layers which result. While the density profile and loop distribution are the same as for equilibrium layers, the final layer comprises a tightly bound inner part plus an outer part whose chains make only fN surface contacts where N is chain length. The contact fractions f follow a broad distribution, P(f) ~ f^{-4/5}, in rather close agreement with strong physisorption experiments [H. M. Schneider et al, Langmuir v.12, p.994 (1996)].