Contact-line pinning controls how quickly colloidal particles equilibrate with liquid interfaces
Published in Soft Matter, 2016
Excerpt of abstract: Previous experiments have shown that spherical colloidal particles relax to equilibrium slowly after they adsorb to a liquid–liquid interface, despite the large interfacial energy gradient driving the adsorption. The slow relaxation has been explained in terms of transient pinning and depinning of the contact line on the surface of the particles. However, the nature of the pinning sites has not been investigated in detail. We use digital holographic microscopy to track a variety of colloidal spheres—inorganic and organic, charge-stabilized and sterically stabilized, aqueous and non-aqueous—as they breach liquid interfaces.