Single particles accelerate final stages of capillary break up

TL;DR

This paper investigates how single particles within a thinning liquid filament accelerate the final stages of capillary break-up, revealing the influence of particle size and distribution on filament dynamics.

Contribution

It identifies the physical mechanisms by which isolated particles cause accelerated thinning in dilute suspensions, highlighting the role of particle size and placement.

Findings

Single particles induce asymmetric filament shapes.

Particle size and distribution affect thinning acceleration.

Accelerated break-up depends on particle positioning.

Abstract

Droplet formation of suspensions is present in many industrial and technological processes such as coating and food engineering. Whilst the finite time singularity of the minimum neck diameter in capillary break-up of simple liquids can be described by well known self-similarity solutions, the pinching of non-Brownian suspension depends in a complex way on the particle dynamics in the thinning thread. Here we focus on the very dilute regime where the filament contains only isolated beads to identify the physical mechanisms leading to the pronounced acceleration of the filament thinning observed. This accelerated regime is characterized by an asymmetric shape of the filament with an enhanced curvature that depends on the size and the spatial distribution of the particles within the capillary thread.