Evaporation kinetics and morphological patterns of a bi-dispersed droplet on a hydrophobic substrate

We report the evaporation kinetics and the morphological deposition pattern of a bi-dispersed droplet over hydrophobic PDMS substrate. Unlike hydrophilic substrate, the droplet on hydrophobic substrate undergoes a distinct evaporation kinetics, which recedes at the very early phases of evaporation and the particles present inside the droplet are driven radially inward to form a centralized deposition pattern with no particles deposited at the edge. A portion of the smaller (fluorescent) particles are deposited at the outermost edge and rest of the particles are at the center as observed under the fluorescent microscopy.