Striped patterns induced by delamination of drying colloidal films

Abstract

The drying of a dispersion of nanoparticles on a solid substrate can result in the formation of spontaneous well-ordered stripe patterns left on the substrate. The evaporation of solvent yields large stresses in the material which usually cause crack formation and delamination from the substrate. The formation of these stripes results from a balance between the drying stress which drives the delamination crack front propagation and the cohesive properties of the material. These solid residues arise behind the crack front and can be perpendicular or parallel to the front. It is then possible to inhibit these structures by modifying the cohesive properties of the material. This self-assembly into an ordered pattern can offer an efficient method to produce a patterned surface in a simple way.