Title: Impact dynamics of surfactant laden drops: Dynamic surface tension effects

Mounir Aytouna - May 11 2009

In collaboration with: Denis Bartolo, Gerard Wegdam, Daniel Bonn, Salima Rafaï

Abstract

We study the impact and subsequent retraction of aqueous surfactant-laden
drops upon high-speed impact on hydrophobic surfaces. Without surfactants, a rapid
expansion of the drop due to the fluid inertia is followed by a rapid retraction, due to the
wetting incompatibility. With surfactants, the retraction can be partly or completely
inhibited. We provide quantitative measurements showing that both the expansion and
the retraction dynamics depend not only on the equilibrium surface tension but also on
the dynamic tension of the surfactant solutions; the latter varies significantly between
different surfactants.