Trapping energy of a spherical particle on a curved liquid interface

Joseph Léandri (1, 2) , Alois Würger (1, 2)

1 CPMOH - Centre de physique moléculaire optique et hertzienne
2 LOMA - Laboratoire Ondes et Matière d'Aquitaine

We derive the trapping energy of a colloidal particle at a liquid interface with contact angle θ and principal curvatures c1 and c2. The boundary conditions at the particle surface are significantly simplified by introducing the shift ε of its vertical position. We discuss the undulating contact line and the curvature-induced lateral forces for a single particle and a pair of nearby particles. The single-particle trapping energy is found to increase with the square of the mean curvature c1 + c2 and to decrease with the square of the anisotropy c1 − c2. Thus particles on a minimal surface (c1 + c2 = 0) move toward strongly curved regions, whereas on a deformed droplet they migrate to flatter areas.

Mots clés: Soft matter; liquid interface; colloidal particles; trapping energy

Domaines: Matière Molle [cond-mat.soft]

Joseph Léandri, Alois Würger. Trapping energy of a spherical particle on a curved liquid interface. 2013. ⟨hal-00785866v1⟩