Interaction between Particles Trapped at Fluid Interfaces: I. Exact and Asymptotic Solutions for the Force between Two Horizontal Cylinders

Abstract Particles or aggregates of particles trapped at fluid interfaces are subjected to capillary forces. This paper is devoted to a force analysis of the capillary interaction between two horizontal cylinders lying side by side on an interface. First, we derive exact expressions for the force of interaction assuming various boundary conditions of physical interest. Then, setting a linear superposition approximation on a rigorous basis, we find two families of asymptotic solutions for small and large particles.