title: Growth kinetics of NaCl crystals in a drying drop of gelatin: transition from faceted to dendritic growth.
abstract: We report a study on the kinetics of drying of a droplet of aqueous gelatin containing sodium chloride. The process of drying recorded as a video clearly shows different regimes of growth leading to a variety of crystalline patterns. Large faceted crystals of ∼mm size form in the early stages of evaporation, followed by highly branched multi-fractal patterns with micron sized features. We simulate the growth using a simple algorithm incorporating aggregation and evaporation, which reproduces the cross-over between the two growth regimes. As evaporation proceeds, voids form in the gel film. The time development of the fluid-void system can be characterized by the Euler number. A minimum in the Euler number marks the transition between the two regimes of growth.
authors.affiliation: Condensed Matter Physics Research Centre, Physics Department, Jadavpur University, Kolkata 700032, India. sujata_tarafdar@hotmail.com mou15july@gmail.com.
authors.forename: Moutushi
authors.initials: M
authors.lastname: Dutta Choudhury
authors.forename: Tapati
authors.initials: T
authors.lastname: Dutta
authors.forename: Sujata
authors.initials: S
authors.lastname: Tarafdar