Self-crumpling elastomers: bending induced by the drying stimulus of a nanoparticle suspension

TL;DR

This study investigates how drying-induced stresses in nanoparticle-coated elastomer disks cause bending and peeling, revealing control mechanisms via particle size and coating thickness.

Contribution

It introduces a model explaining the early-stage curvature due to drying stresses and demonstrates control of peeling through nanoparticle and coating parameters.

Findings

Drying induces tensile stresses in nanoparticle coatings.

Bending is controlled by particle size and coating thickness.

A successful model describes initial curvature behavior.

Abstract

We report an experimental study of the drying-induced peeling of a bilayer, consisting of an elastomeric disk coated with a suspension of nanoparticles. We show that although capillary forces associated with the scale of the droplet can not compete with the adhesion of the elastomer on a surface, nevertheless large tensile stresses develop in the coating, which results in a moment bending the bilayer. We attribute this stress to the nano-menisci in the pores of the colloidal material and we propose a model that describes successfully the early stage curvature of the bilayer. Thus, we show that the peeling can be conveniently controlled by the particle size and the coating thickness.