Particles disappear, phase segregation is shown*

In fluid dynamics, tracer particles are commonly used for flow visualization because many fluids are transparent. In this study, we introduce a unusual experiment where seeded fluorescent polystyrene particles are dissolved at a specific concentration ratio between two liquid components, which we use to identify molecular segregation in a binary mixture droplet during evaporation. This selective evaporation phenomenon has never been observed in experimental results. In addition, we develop a theoretical model in good agreement with the experimental results. We expect that understanding of the evaporation mechanism of a multi-component liquid droplet will provide some insights to construct mixture components depending upon various physicochemical applications, such as ink-jet printing, spray coating, and droplet-based microfluidics for biochemical and biomedical applications.