When does the elastic regime begin in viscoelastic pinch-off?

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Gaillard, A., Herrada, M. A., Deblais, A., van Poelgeest, C., Laruelle, L., Eggers, J., Bonn, D.
Format: Preprint
Published: 2024
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866916273874534400
author Gaillard, A.
Herrada, M. A.
Deblais, A.
van Poelgeest, C.
Laruelle, L.
Eggers, J.
Bonn, D.
author_facet Gaillard, A.
Herrada, M. A.
Deblais, A.
van Poelgeest, C.
Laruelle, L.
Eggers, J.
Bonn, D.
contents In this experimental and numerical study, we revisit the question of the onset of the elastic regime in viscoelastic pinch-off. This is relevant for all modern filament thinning techniques which aim at measuring the extensional properties of low-viscosity polymer solutions such as the Slow Retraction Method (SRM) in Capillary Breakup Extensional Rheometry (CaBER) as well as the dripping method where a drop detaches from a nozzle. In these techniques, a stable liquid bridge is slowly brought to its stability threshold where capillary-driven thinning starts, slowing down dramatically at a critical radius $h_1$ marking the onset of the elastic regime where the bridge becomes a filament with elasto-capillary thinning dynamics. While a theoretical scaling for this transition radius exists for the classical step-strain CaBER protocol, where polymer chains stretch without relaxing during the fast plate separation, we show that it is not necessarily valid for a slow protocol such as in SRM since polymer chains only start stretching (beyond their equilibrium coiled configuration) when the bridge thinning rate becomes comparable to the inverse of their relaxation time. We derive a universal scaling for $h_1$ valid for both low and high-viscosity polymer solution which is validated by both CaBER (SRM) experiments with different polymer solutions, plate diameters and sample volumes and by numerical simulations using the FENE-P model.
format Preprint
id arxiv_https___arxiv_org_abs_2406_02303
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle When does the elastic regime begin in viscoelastic pinch-off?
Gaillard, A.
Herrada, M. A.
Deblais, A.
van Poelgeest, C.
Laruelle, L.
Eggers, J.
Bonn, D.
Soft Condensed Matter
Fluid Dynamics
In this experimental and numerical study, we revisit the question of the onset of the elastic regime in viscoelastic pinch-off. This is relevant for all modern filament thinning techniques which aim at measuring the extensional properties of low-viscosity polymer solutions such as the Slow Retraction Method (SRM) in Capillary Breakup Extensional Rheometry (CaBER) as well as the dripping method where a drop detaches from a nozzle. In these techniques, a stable liquid bridge is slowly brought to its stability threshold where capillary-driven thinning starts, slowing down dramatically at a critical radius $h_1$ marking the onset of the elastic regime where the bridge becomes a filament with elasto-capillary thinning dynamics. While a theoretical scaling for this transition radius exists for the classical step-strain CaBER protocol, where polymer chains stretch without relaxing during the fast plate separation, we show that it is not necessarily valid for a slow protocol such as in SRM since polymer chains only start stretching (beyond their equilibrium coiled configuration) when the bridge thinning rate becomes comparable to the inverse of their relaxation time. We derive a universal scaling for $h_1$ valid for both low and high-viscosity polymer solution which is validated by both CaBER (SRM) experiments with different polymer solutions, plate diameters and sample volumes and by numerical simulations using the FENE-P model.
title When does the elastic regime begin in viscoelastic pinch-off?
topic Soft Condensed Matter
Fluid Dynamics
url https://arxiv.org/abs/2406.02303