Lifetimes of two-dimensional droplets on smooth wetting patterns #

Matthew Haynes, Marc Pradas

11:30 Wednesday in 3Q16.

Part of the Evaporation session.

Abstract #

In this talk, we shall examine the evolution and lifetime of droplets evaporating on a smooth chemical pattern, characterised by a spatially varying contact angle. We will formulate a model that combines the evaporation rate of the droplet with the static stability of the droplet as the volume changes in time quasi-statically. We will present an exact equation for the evaporation rate which is then studied analytically under the limiting cases of nearly neutral wetting and highly hydrophilic conditions. We shall show that the evaporation rate of the droplet is highly dependent on the size and shape of the fictitious infinity where a far-field boundary condition needs to be applied. Time permitting, we can also discuss how the droplet’s lifetime depends on the averaged contact angle and strength of a chemical pattern.