Droplet drying

Drying of colloidal suspension is a fascinating process where a liquid phase transforms into a dense or porous solid. This transformation involves various physical mechanisms, including the diffusion of liquid molecules into the atmosphere and the movement of dispersed particles driven by evaporation. The resulting dried patterns often resemble the familiar stain left by a dried coffee drop, a phenomenon known as the "coffee ring effect". Our research explores how local constituent's properties—such as charge, shape, and interactions—affect these dried patterns. Understanding these relationships is crucial for advancing the development of coatings and improving the effectiveness of paints and protective layers.

References:

• Capillary flow as the cause of ring stains from liquid drops, R. D. Deegan et al., Nature, 389, 827-829 (1997).  [Literature]

• Physics of drying drop: flow field, pattern formation, and desiccation cracks, Ranajit Mondal, Hisay Lama and K.C. Sahu, Physics of Fluids, 35, 061301 (2023).

• Modulation of Central Depletion Zone in Evaporated Sessile Drop via Substrate  Heating, Hisay Lama, Dillip K. Satapathy, Madivala G. Basavaraj, Langmuir, 36 (17), 4737-4744 (2020).