Adhesion of spheres by thin liquid films

Abstract

Abstract Thin liquid films may produce significant adhesion between solid bodies, such as powder agglomerates and ultra-flat surfaces. The adhesive force can be split into two components; the meniscus force and a viscous component which, at sufficiently high deformation rates, will become dominant. This paper presents an analysis for the viscous component of adhesion acting between spheres coated by thin liquid layers, which is expressed as the impulse required to separate the spheres. This impulse depends on the radii and surface roughness of the spheres, and the fluid viscosity and thickness. The dependence on the roughness and quantity of fluid is unexpectedly weak (i.e. logarithmic). The predictions of the analysis are confirmed by direct experiment using a simple force pendulum.