(298b) Preventing Buckling in Drying Suspensions of Anisotropic Particles

Solvent evaporation in unpinned droplets of colloidal suspensions leads to the formation of porous shells which buckle under the pressure differential imposed by drying. We investigate the role of aspect ratio of rod-shaped particles in suppressing such buckling instabilities. Longer, thinner rods pack into permeable shells with consequently lower Darcy’s pressure and thus avoid buckling. Our results reveal the role of particle morphology in suppressing buckling and indicate particle shape as a tunable parameter for emerging mechanical stability in unpinned droplets. From an industrial perspective, this highlights the economic advantage in exploiting the properties conveyed by shape to optimize food and drug micro-processing.