Physical Review Journal Club: How Elasticity Affects Bubble Pinch-Off
Friday, September 25, 2026
9 a.m. ET, 3 p.m. CET
Free Registration
The Physical Review Journal Club returns with a discussion with author Coen Verschuur (University of Twente), presenting their recently published Physical Review Fluids article, “How elasticity affects bubble pinch-off.”
Pinch-off is the rapid thinning and eventual break-up of a fluid neck, associated with a hydrodynamic singularity. In many applications such as inkjet printing and spraying, the liquid phase is viscoelastic. Viscoelastic effects have been well investigated for drop pinch-off, where even very small polymer concentration can strongly delay drop breakup by forming long liquid threads. Much less attention has been paid to bubble pinch-off, despite fundamental differences with drop pinch-off due to the relative contribution of inertia, surface tension, and viscoelastic stresses.
In this paper, the authors use experiments to measure the formation, thinning and break-up of the air neck during bubble pinch-off in a polymer solution, complemented by numerical simulations and analytical modelling. They show that for low polymer concentration, the viscoelastic delay is absent because polymers are predominantly stretched in the radial direction, perpendicular to the direction of the neck elongation. The polymer stretching is unable to compete with the inertial collapse governing bubble pinch-off. In drop pinch-off, by contrast, polymers are elongated in the direction of the neck, opposing its thinning. Viscoelastic delay emerges in bubble pinch-off only for larger polymer concentrations, but becomes dependent on the needle diameter. These results highlight significant quantitative and mechanistic differences between drop and bubble pinch-off in viscoelastic fluids.
After the presentation, the authors will answer questions from the audience in a live Q&A session, moderated by PRFluids Associate Editor Chao Sun (Tsinghua University).
Read ahead:
How elasticity affects bubble pinch-off
C.I. Verschuur, A.T. Oratis, V. Sanjay and J.H. Snoeijer
Phys. Rev. Fluids 11, 073302
