Droplet dissolution driven by emerging thermal gradients and Marangoni flow

Abstract

The lifetime $\ensuremath{\tau}$ of an isothermal and purely diffusively dissolving droplet in a host liquid scales as $\ensuremath{\tau}\ensuremath{\sim}{R}_{0}^{2}$ with its initial radius ${R}_{0}$. Here we experimentally find and theoretically derive a completely different droplet dissolution behavior, resulting in $\ensuremath{\tau}\ensuremath{\sim}{R}_{0}^{4}$. It occurs when the dissolution dynamics is controlled by local heating of the liquid, leading to a modified solubility and a thermal Marangoni flow around the droplet.