Fig. 3.

Calculated deformations and capillary interactions for colloidal particles on a saddle-shaped interface. (A) Calculated deformation field around a spherical particle with radius a = 1 μm on a catenoid interface with D = 0.02 μm⁻¹; blue regions indicate a depression of the interface and red regions a rise of the interface. (B) Calculated interaction energy between two particles (a = 1 μm) on catenoid interfaces of different curvature as a function of separation distance, for two relative orientations with respect to the principal curvature axis of the interface. Interfacial tension γ = 30 mN/m, and contact angle θ = 90° in these calculations. (C) Superimposed interaction curves for particles approaching along principal axis for different a and D, showing −U/[(γa²)(Da)²] as a function of (r/a). The black points indicate the analytical prediction for the far field (24).