Order of Three-Phase (Solid-Liquid-Gas) Contact Line Tension Probed by Simulation of Three-Phase Contact Line Expansion on Small Hydrophobic Spheres

Abstract

Expansion of the three-phase (solid–liquid–gas) contact line on the surface of silanated glass spheres was experimentally studied by means of a CCD high-speed video technique. The dependence of the central angle (measured at the particle center) of the contact line on time was determined. This dependence was theoretically simulated. Results of this simulation show a strong effect of line tension on the kinetics of the three-phase contact expansion. Order of the line tension (μJ/m) is the same as that determined by A.W. Neumann and co-workers for similar hydrophobic surfaces by means of different techniques.