Study finds a way to predict when cracks would develop in paint, clay, milk and blood

Sub : Sci

Sec : Miscellaneous

Why in NEWS

A new study have shown clay’s drying process reveals a fascinating shift in elasticity, from liquid to pliable solid to brittle material.

Key highlights and context

Crack Prevention Breakthrough: Researchers at the Raman Research Institute (RRI) in Bengaluru have discovered a method to delay cracking in paint coatings.
Wider Applications: This technique has potential uses beyond paint, including disease diagnosis and food spoilage detection.
Ubiquity of Cracks: Cracks are common in various settings, from old vases and buildings to lava flows, dry ground, and reptile skin.
Crack Complexity: While seemingly simple, crack formation is a complex phenomenon.
Crack Intersection Angles: Previous research showed cracks typically intersect at 90 degrees, except in drying paint where the angle is 120 degrees.

Elasticity

Elasticity, ability of a deformed material body to return to its original shape and size when the forces causing the deformation are removed.

Elasticity and Cracking

The changing elasticity of clay as it dries, transitioning from liquid to soft solid to brittle sheet.
They discovered a relationship between clay’s elasticity and the speed at which cracks appear.
They developed a method to predict crack formation based on initial sample thickness and elasticity.
By manipulating elasticity, they could delay the onset of cracks. They altered elasticity by adding different substances to the clay.
Common salt accelerated crack formation, while tetrasodium pyrophosphate (TSPP) significantly delayed it. TSPP, a food additive found in various products (e.g., chicken nuggets, marshmallows, toothpaste), proved highly effective in delaying cracks in clay.

Application of delayed cracking

The research can be immediately applied to create crack-resistant paint coatings by adding clay with specific elasticity during manufacturing.
The findings have potential applications beyond paint, wherever cracks occur. Milk and blood, like clay, are colloids (mixtures of particles in a liquid) and exhibit similar drying behavior.
Crack patterns can reveal structural changes in materials like milk (protein networks) and blood (clot formation).
The method could be used to identify adulterants in milk by analysing differences in drying patterns between pure and adulterated samples.
Changes in red blood cell characteristics in diseases like anemia could alter blood drying patterns, offering a potential diagnostic tool.