Wettability Induced Crack Dynamics and Morphology

TL;DR

This study investigates how substrate wettability influences crack formation, morphology, and particle arrangements in drying colloidal films, revealing that increased hydrophobicity reduces crack numbers through stress dissipation.

Contribution

It provides experimental and theoretical insights into the role of substrate surface energy on crack dynamics in colloidal films, linking wettability to crack control mechanisms.

Findings

Number of cracks decreases with increased substrate hydrophobicity

DLVO theory predictions align with experimental results

Stress dissipation explains crack suppression on hydrophobic surfaces

Abstract

Substrate wettability alteration induced control over crack formation process in thin colloidal films has been addressed in the present study. Colloidal nanosuspension (53nm, mean particle diameter) droplets have been subjected to natural drying to outline the effects of substrate surface energies over the dry-out characteristics with emphasis on crack dynamics, crack morphology and underlying particle arrangements. Experimental findings indicate that number of cracks formed decreases with increase in substrate hydrophobicity. These physical phenomena have been explained based on the magnitude of stress dissipation incurred by the substrate. DLVO predictions are also found to be in tune with the reported experimental investigations.