Pattern formation in desiccated sessile colloidal droplets with salt admixture: Short review

TL;DR

This review discusses the mechanisms and factors influencing pattern formation in desiccated colloidal droplets with salt, highlighting its scientific and practical significance in fields like medicine and coating technology.

Contribution

It synthesizes current understanding of pattern formation mechanisms in salt-containing colloidal droplets and emphasizes the importance of various physical and chemical factors affecting final patterns.

Findings

Pattern formation depends on salt concentration and fluid properties.

Wetting and substrate interactions significantly influence dried film morphology.

Understanding these processes aids in medical diagnostics and coating improvements.

Abstract

This short review is devoted to the simple process of drying a multi-component droplet consisting of a complex fluid containing a salt. These processes provide a fascinating subject for study. The explanation of the rich variety of patterns formed is not only an academic challenge, but a problem of practical importance, as applications are growing in medical diagnosis and improvement of coating/printing technology. The fundamental scientific problem is the study of the mechanism of micro- and nanoparticle self-organization in open systems. The specific fundamental problem to be solved, related to this system is - the investigation of the mass transfer processes, the formation and evolution of phase fronts and the identification of mechanisms of pattern formation. The drops of liquid containing dissolved substances and suspended particles are assumed to be drying on a horizontal solid substrate. The chemical composition and macroscopic properties of the complex fluid, the concentration and nature of the salt, the surface energy of the substrate and the interaction between the fluid and substrate which determines the wetting, all affect the final morphology of the dried film.