Controlling polyelectrolyte adsorption onto carbon nanotubes by tuning ion-image interactions

TL;DR

This paper presents a mean-field model demonstrating that ion-image interactions significantly influence polyelectrolyte adsorption on conducting carbon nanotubes, offering a new way to control nanotube functionalization by tuning electronic properties and salt conditions.

Contribution

The study introduces a simple mean-field model highlighting ion-image attraction as a key factor in polyelectrolyte adsorption, enabling selective and reversible nanotube functionalization.

Findings

Ion-image attraction significantly affects adsorption at low salt concentrations.

Electronic structure of nanotubes influences ion-image interactions and adsorption.

Proposes a strategy for reversible nanotube functionalization by tuning ion-image interactions.

Abstract

Understanding and controlling polyelectrolyte adsorption onto carbon nanotubes is a fundamen- tal challenge in nanotechology. Polyelectrolytes have been shown to stabilise nanotube suspensions through adsorbing onto the nanotube surface, and polyelectrolyte-coated nanotubes are emerging as building blocks for complex and addressable self-assembly. The conventional wisdom suggests that polyelectrolyte adsorption onto nanotubes is driven by specific chemical or van der Waals interac- tions. We develop a simple mean-field model and show that ion-image attraction is a significant effect for adsorption onto conducting nanotubes at low salt concentrations. Our theory suggests a simple strategy to selectively and reversibly functionalize carbon nanotubes based on their electronic structure which in turn modifies the ion-image attraction.