Dewetting kinetics between a gas bubble and a flat solid surface and the effect of three-phase solid–gas–liquid contact line tension

Abstract

The expansion of the three-phase contact between a small air bubble and a flat solid surface is studied experimentally by means of a CCD high-speed video technique. Quartz surfaces are rendered hydrophobic by the Langmuir–Blodgett technique and by methylation. Our molecular-kinetic model for TPC expansion, which accounts for the effect of solid–gas–liquid three-phase contact line tension, is used successfully to describe the experimental dewetting data. The line tension is a relevant parameter which controls the dewetting and coalescence processes with a small wetting perimeter. The order of the line tension in our experiments is 1 μJ m −1, which is consistent with the data obtained by other measuring techniques for similar hydrophobic surfaces.