Micrometric particles twodimensional self-assembly during drying of liquid film

TL;DR

This study models the self-assembly of micrometric spherical particles during the drying of a thin liquid film on different substrates, revealing pattern formations influenced by substrate topography, supported by experimental validation.

Contribution

It provides a numerical model of 2D particle self-organization during drying, highlighting the impact of substrate indents on pattern formation, validated by experiments.

Findings

Flat substrates produce linear patterns and small clusters.

Indented substrates cause particle aggregation along rougher sides.

Experimental results confirm the numerical predictions.

Abstract

We computed the self-organisation process of a monodisperse collection of spherical micrometric particles trapped in a two-dimensional (2D) thin liquid film isothermally dried on a chemically inert substrate. The substrate is either flat or indented to create linear stripes on its surface. The numerical results are illustrated and discussed in the light of experimental ones obtained from the drying of diamond particles water based suspension ($d_{50} = 10 \mu m$) on a glass substrate. The drying of the suspension on a flat substrate leads to the formation of linear patterns and small clusters of micrometric particles distributed over the whole surface of the substrate, whereas the drying of the suspension on a indented substrate leads to the aggregation of the particles along one side of the stripe which has a higher roughness than the other side of the stripe. This is an easy experimental way to obtain colloidal selforganized patterns.