Analysis of Liquid Bridge Formation and Adhesion Force between Two Particles of Different Sizes

Abstract

The profiles of liquid bridges formed between two spherical particles of different sizes, including a spherical particle and a flat plate, where the bridges are in equilibrium with surrounding humidities have been theoretically analyzed for contact angles of liquid to particle of 060°. The adhesion force arising from liquid bridges is also analyzed on the basis of the Laplace equation. The results were similar to those obtained by our previous theory for two identical spheres, in which the profiles were expressed as a function of surrounding humidities and solute concentrations in the liquid. The neck radius of a bridge formed by pure water was very small (about 0.15100nm), whereas that formed by liquid containing soluble impurities was large and controlling in most actual cases.
The adhesion force theoretically related to bridge profiles was verified by tensile strength tests of water bridges formed between glass spheres of different sizes and between a glass sphere and a slide glass.