A comprehensive study of thermocapillary rupture of liquid layer

Abstract

There is a lack of understanding of the physical mechanisms involved in the rupture of a liquid film on a solid surface. This is in part due to the large number of parameters of the liquid film—substrate system on which this complex process is dependent. Due to the thermocapillary effect, local heating can have a destabilizing effect on the stability of the film. In this work, using a numerical model verified by the experimental data, the influence of parameters not available for variation in the experiment has been studied. It was found that the formation of dry spots in a locally heated liquid film occurs only under the influence of thermocapillary forces. In turn, the expansion of the dry spots takes place under the influence of the capillary forces. Thus, until the dry spot appears, the rupture does not differ on either hydrophilic or superhydrophobic substrates, but the contact line velocity during dry spot growth is extremely sensitive to the contact angle.