Effective interactions of colloids on nematic films

Abstract

The elastic and capillary interactions between a pair of colloidal particles trapped on top of a nematic film are studied theoretically for large separations $d$. The elastic interaction is repulsive and of quadrupolar type, varying as $d^{-5}$. For macroscopically thick films, the capillary interaction is likewise repulsive and proportional to $d^{-5}$ as a consequence of mechanical isolation of the system comprised of the colloids and the interface. A finite film thickness introduces a nonvanishing force on the system (exerted by the substrate supporting the film) leading to logarithmically varying capillary attractions. However, their strength turns out to be too small to be of importance for the recently observed pattern formation of colloidal droplets on nematic films.

13 pages, accepted by EPJE

References in corpus (9)

• Direct measurements of the effects of salt and surfactant on interaction forces between colloidal particles at water-oil interfaces
• Ordered droplet structures at the liquid crystal surface and elastic-capillary colloidal interactions
• Effective capillary interaction of spherical particles at fluid interfaces
• Electric-field induced capillary interaction of charged particles at a polar interface
• Force balance of particles trapped at fluid interfaces
• Attractions between charged colloids at water interfaces
• Theory of capillary-induced interactions beyond the superposition approximation
• Effective pair interactions between colloidal particles at a nematic-isotropic interface
• Capillary-induced interactions between colloids at an interface

Cited by in corpus (5)

• Exploiting imperfections: Directed assembly of surface colloids via bulk topological defects
• Dynamics of colloidal particles with capillary interactions
• Theory of Elastic Interaction of the Colloidal Particles in the Nematic Liquid Crystal Near One Wall and in the Nematic Cell
• Free energy of colloidal particles at the surface of sessile drops
• Theory of elastic interaction between colloidal particles in the nematic cell in the presence of the external electric or magnetic field