Colloidal deposits from evaporating sessile droplets: A computationally efficient framework for predicting the final deposit shape

Abstract

A modeling framework for the complete evaporation of particle-laden droplets, including touchdown events where the air-liquid interface approaches the substrate, is presented. The inclusion of particle jamming into the model, creating a transition from free advection to an immobile porous plug, is essential to making realistic predictions for the deposit's dimensions. By removing the need to track jammed particle fronts explicitly, as often considered, we are able to run simulations until solute has jammed everywhere in the drop. This allows for valid comparisons with experimental findings on the dried deposit's topography. Our model can also be easily applied to general contact line geometries, allowing us to explore the influence of contact line curvature on the local deposit profile.