Adsorption of polydisperse polymer chains

TL;DR

This paper investigates how the distribution of chain lengths in polydisperse ideal polymers affects their adsorption behavior, revealing conditions for phase transition and divergence in adsorption density.

Contribution

It demonstrates that the tail of the chain length distribution determines the adsorption transition, highlighting the importance of distribution decay rate.

Findings

Adsorption transition occurs only if the chain length distribution decays slower than exponentially.

Exponential decay in chain distribution leads to continuous divergence of adsorption density.

Repulsive interactions do not alter the qualitative adsorption behavior at low coverages.

Abstract

The adsorption of polydisperse ideal polymer chains is shown to be sensitive to the large N tail of the distribution of chains. If and only if the number of chains decays more slowly than exponentially then there is an adsorption transition like that of monodisperse infinite chains. If the number decays exponentially the adsorption density diverges continuously at a temperature which is a function of the mean chain length. At low coverages, chains with repulsive monomer--monomer interactions show the same qualitative behaviour