Morphometric analysis of polygonal cracking patterns in desiccated starch slurries

TL;DR

This study analyzes the geometry of polygonal cracking in dried starch slurries, revealing how starch type and slurry thickness influence crack patterns and their underlying physical mechanisms.

Contribution

It provides new insights into how starch grain properties affect crack formation and distribution in desiccated starch films.

Findings

Different starch types show distinct crack evolution patterns.

Slurry thickness affects the distribution of polygonal cell areas.

Starch grain shape and size influence water transport and stress fields.

Abstract

We investigate the geometry of two-dimensional polygonal cracking that forms on the air-exposed surface of dried starch slurries. Two different kinds of starches, made from potato and corn, exhibited distinguished crack evolution, and there were contrasting effects of slurry thickness on the probability distribution of the polygonal cell area. The experimental findings are believed to result from the difference in the shape and size of starch grains, which strongly influence the capillary transport of water and tensile stress field that drives the polygonal cracking.