Drying Pathways of an Evaporating Soft Matter Droplet

Scaling mechanical instabilities in drying micellar droplets

“…Evaporation-driven drying of particle-laden sessile droplets is a well-known phenomenon due to its enormous curiosity-driven fundamental interests, [1][2][3][4][5][6][7][8][9][10][11] and importance in many applicative fields, spanning from mesoscale to geological length scales. The capillary force between the particles helps to arrange them into an aggregated morphology.…”

“…The drying-induced stress generated during the evaporation of a colloidal drop can lead to various mechanical instabilities such as cavitation, buckling, wrinkling, etc., even during the evaporative drying. 2,5 Complete evaporation of the solvent turns the sessile droplets into a solid. This can further generate mechanical instabilities in the dried deposits, such as wrinkles, 2,4,5 folds, and buckles, 4,5 and quite often releases compressive stresses by the formation of cracks provided the capillary stress overcomes a threshold value.…”

“…4 Such gel-like zone is closely discussed as the outmost 'crust' layer of the evaporating droplet and is believed to be related to the final morphology of the dried solution droplet, including its deposit. 2 Besides, few studies have been performed to investigate the role of substrate temperature on evaporation-driven drying 27,28 and the resulting crack morphologies. 3 In the case of drying droplets, an enhanced temperature gradient created between the base and the apex of the drying droplet generates a reverse inward Marangoni flow.…”