Drying of a Microdroplet of Water Suspension of Nanoparticles: from Surface Aggregates to Microcrystal

TL;DR

This study investigates the drying process of a levitated water droplet containing nanoparticles, revealing how surface aggregates form and transform into microcrystals through self-assembly, supported by experimental observations and numerical simulations.

Contribution

It introduces a detailed analysis of nanoparticle self-assembly during droplet evaporation, combining experimental and numerical methods to understand morphology evolution.

Findings

Successful formation of microcrystals from nanoparticle suspensions.

Numerical simulations align well with observed morphologies.

Identified stages of droplet drying and particle aggregation.

Abstract

The method of formation of nanoparticle aggregates such as high-coverage spherical shells of microspheres or 3-D micro crystals grown in the geometry unaffected by a substrate is described. In the reported experiment, the evaporation of single levitated water droplet containing 200 nm diameter polystyrene spheres was studied. Successive stages of the drying process were discussed by analyzing the intensity of light elastically scattered by the evaporating droplet. The numerically simulated self-assembly coincides nicely with the observed morphologies resulting from transformation of a droplet of suspension into a solid microcrystal via kinetically driven self-assembly of nanostructures.