Capillary force and torque on spheroidal particles floating at a fluid interface beyond the superposition
1Université Paris Diderot, Sorbonne Paris Cité, Laboratoire Matière et Systèmes Complexes (MSC), UMR 7057 CNRS, F-75205 Paris, France.
Physical Review. E
|March 18, 2016
Summary
We analytically determined the capillary energy for spheroidal colloids on fluid interfaces. The study reveals attractive interactions between particles, crucial for understanding colloidal behavior in complex fluids.
Area of Science:
- Colloid science
- Fluid dynamics
- Surface physics
Background:
- Colloidal particles at fluid interfaces exhibit capillary interactions.
- Understanding these interactions is key to predicting colloidal assembly and behavior.
Purpose of the Study:
- To analytically determine the capillary energy of a spheroidal colloid on a deformed fluid interface.
- To investigate the asymptotic interaction between two spheroidal particles at large separations.
Main Methods:
- A perturbative scheme was employed to derive analytical expressions.
- Results were validated using exact numerical calculations.
- Asymptotic analysis was used to determine inter-particle interactions.
Main Results:
- Capillary energy is expressed in terms of the local curvature tensor of the background deformation.
- The dominant interaction between two spheroidal particles is quadrupolar (d^-4).
- A next-to-leading order attraction (d^-8) was identified, independent of orientation.
Conclusions:
- The perturbative approach provides accurate analytical results for small ellipticity and surface deformations.
- The derived interaction potentials are essential for modeling colloidal systems with non-spherical particles.
- The study elucidates the nature and scaling of interactions between spheroidal colloids.
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