Self-similarity in the breakup of very dilute viscoelastic solutions

TL;DR

This paper investigates the self-similar breakup of dilute viscoelastic polymer solutions, demonstrating that experimental interface profiles align well with a theoretical model based on the Oldroyd-B framework.

Contribution

The study revisits experimental data and shows that the Oldroyd-B model accurately describes the self-similar filament breakup in very dilute viscoelastic solutions.

Findings

Experimental interface profiles match the Oldroyd-B model predictions.

Self-similar shapes are observed near the filament end during breakup.

High-resolution measurements confirm the theoretical description.

Abstract

When pushed out of a syringe, polymer solutions form droplets attached by long and slender cylindrical filaments whose diameter decreases exponentially with time before eventually breaking. In the last stages of this process, a striking feature is the self-similarity of the solution shape near the end of the filament. This means that shapes at different times, if properly rescaled, collapse onto one universal shape. A theoretical description inspired by this similarity observation and based on the Oldroyd-B model was recently shown to disagree with existing experimental results. By revisiting these measurements and analysing the interface profiles of very diluted polyethylene oxide solutions at high temporal and spatial resolution, we show that they are very well described by the model.