title: Onset of buckling in drying droplets of colloidal suspensions.
abstract: Minute concentrations of suspended particles can dramatically alter the behavior of a drying droplet. After a period of isotropic shrinkage, similar to droplets of a pure liquid, these droplets suddenly buckle like an elastic shell. While linear elasticity is able to describe the morphology of the buckled droplets, it fails to predict the onset of buckling. Instead, we find that buckling is coincident with a stress-induced fluid to solid transition in a shell of particles at a droplet's surface, occurring when attractive capillary forces overcome stabilizing electrostatic forces between particles.
authors.affiliation: DEAS and Department of Physics, Harvard University, Cambridge, MA 02138, USA.
authors.forename: N
authors.initials: N
authors.lastname: Tsapis
authors.forename: E R
authors.initials: ER
authors.lastname: Dufresne
authors.forename: S S
authors.initials: SS
authors.lastname: Sinha
authors.forename: C S
authors.initials: CS
authors.lastname: Riera
authors.forename: J W
authors.initials: JW
authors.lastname: Hutchinson
authors.forename: L
authors.initials: L
authors.lastname: Mahadevan
authors.forename: D A
authors.initials: DA
authors.lastname: Weitz