Observation of Marangoni flow in ordinary and self-rewetting fluids using optical diagnostic systems

Dilute aqueous solutions of alcohols with a high number of carbon atoms can be considered as self-rewetting fluids due to their properties associated to an anomalous dependency of the surface tension with temperature in some ranges of concentrations. In this paper research activities focused on numerical simulations and laboratory experiments of the behaviour of a thin layer of liquid subject to a horizontal thermal gradient. The investigated liquids include ordinary liquids and water/alcohols mixtures. Physical properties measurements, in particular surface tension and refractive index, are also presented. Flow visualization and interferometric analysis have been carried out using optical diagnostic systems.