Ellipsoidal particles at fluid interfaces

Ellipsoidal particles at fluid interfaces.

For partially wetting, ellipsoidal colloids trapped at a fluid interface, their effective, interface-mediated interactions of capillary and fluctuation-induced type are analyzed. For contact angles different from 90( degrees ) , static interface deformations arise which lead to anisotropic capillary forces that are substantial already for micrometer-sized particles. The capillary problem is sol...

Assembling ellipsoidal particles at fluid interfaces using switchable dipolar capillary interactions.

How to dynamically tune an assembly of anisotropic colloidal particles adsorbed at fluid-fluid interfaces using dipolar capillary interactions is demonstrated. A previously discovered first-order phase transition is exploited and it is shown how to spontaneously turn off these dipolar capillary interactions by exceeding a critical field strength, providing unprecedented control of the bottom-up...

Specific properties of amphiphilic particles at fluid interfaces

We present a theoretical and experimental study of amphiphilic particles : these are small solid spheres treated so that one part of the solid is hydrophilic whereas the other is hydrophobic. These beads have a specific behaviour at the interface between two fluids of different polarities since they are anchored at the interface along the border line between the two parts, in a large range of v...

Capillary interactions between colloidal particles at curved fluid interfaces

Force balance of particles trapped at fluid interfaces.

We study the effective forces acting between colloidal particles trapped at a fluid interface which itself is exposed to a pressure field. To this end, we apply what we call the "force approach," which relies solely on the condition of mechanical equilibrium and turns to be in a certain sense less restrictive than the more frequently used "energy approach," which is based on the minimization of...