Evaporation of sessile water droplets: Universal behaviour in presence of contact angle hysteresis

A theory is presented, which describes the diffusion limited evaporation of sessile water droplets in presence of contact angle hysteresis. Theory describes two stages of evaporation process: (I) evaporation with a constant radius of the droplet base; and (II) evaporation with a constant contact angle. During stage (I) the contact angles decreases from static advancing contact angle to static receding contact angle. During stage (II) the contact angle remains equal to the static receding contact angle. Universal dependences are deduced for both evaporation stages. Obtained universal curves are validated against available in the literature experimental data. (C) 2011 Elsevier B.V. All rights reserved.