Pattern Formation in a Drying Drop of Starch Gel with Sodium Chloride

TL;DR

This study investigates the complex pattern formation in a drying drop of starch gel containing sodium chloride, revealing salt crystallization and starch segregation phenomena through visual analysis.

Contribution

It provides new insights into the segregation and pattern formation mechanisms in drying starch gel drops with salt, combining experimental observations with micrographic analysis.

Findings

Salt forms radial dendritic crystals near the center

Starch segregates into a transparent peripheral band

Concentric rings with distinct textures are observed

Abstract

A drop of aqueous potato starch gel with a certain mole fraction of NaCl, when dried on a glass slide, exhibits strong segregation and intricate pattern formation phenomena. The salt forms radial dendritic crystalline aggregates near the centre, with the starch separating out in the form of a transparent band at the periphery. Photographs and micrographs show a series of concentric rings with different texture.