Stability and interactions of nanocolloids at fluid interfaces: effects of capillary waves and line tensions

Abstract

We analyze the effective potential for nanoparticles trapped at a fluid interface within a simple model which incorporates surface and line tensions as well as a thermal average over interface fluctuations (capillary waves). For a single colloid, a reduced steepness of the potential well hindering movements out of the interface plane compared to rigid interface models is observed, and an instability of the capillary wave partition sum in case of negative line tensions is pointed out. For two colloids, averaging over the capillary waves leads to an effective Casimir--type interaction which is long--ranged, power-like in the inverse distance but whose power sensitively depends on possible restrictions of the colloid degress of freedom. A nonzero line tension leads to changes in the magnitude but not in the functional form of the effective potential asymptotics.

19 pages, Proceedings of CODEFII (Bonn, March 31 - Apr 2, 2008), JPCM (to appear)

References in corpus (12)

• The 'Cheerios effect'
• Direct measurements of the effects of salt and surfactant on interaction forces between colloidal particles at water-oil interfaces
• Conceptual aspects of line tensions
• Casimir Forces between Compact Objects: I. The Scalar Case
• The Casimir Effect and Geometric Optics
• Capillary Waves in a Colloid-Polymer Interface
• Effective capillary interaction of spherical particles at fluid interfaces
• Non perturbative approach to Casimir interactions in periodic geometries
• Electric-field induced capillary interaction of charged particles at a polar interface
• Effective forces between colloids at interfaces induced by capillary wave-like fluctuations
• The Importance of Boundary Conditions for Fluctuation Induced Forces between Colloids at Interfaces
• Surface-mediated attraction between colloids

Cited by in corpus (5)

• Fluctuation-induced forces between inclusions in a fluid membrane under tension
• Molecular simulation of translational and rotational diffusion of Janus nanoparticles at liquid interfaces
• Solvent-mediated interactions between nanoparticles at fluid interfaces
• Anisotropies in thermal Casimir interactions: ellipsoidal colloids trapped at a fluid interface
• Line tension and reduction of apparent contact angle associated with electric double layers