Related Experiment Video
Updated: Sep 8, 2025

Studying Large Amplitude Oscillatory Shear Response of Soft Materials
Published on: April 25, 2019
Scaling purely elastic instability of strongly shear thinning polymer solutions
Pegah Shakeri1, Michael Jung1, Ralf Seemann1
1Experimental Physics, Saarland University, 66123 Saarbrücken, Germany and Max Planck Institute for Dynamics and Self-Organization, 37077 Göttingen, Germany.
Abstract:
Flow of viscoelastic polymer solutions in curved channels exhibits instability caused by the elastic nature of polymers even at low Reynolds numbers. However, scaling of the onset of this purely elastic instability in semidilute polymer solutions has not been previously reported. Here we experimentally investigate the flow of highly elastic polymer solutions above their overlap concentrations using pressure measurements and particle image velocimetry. We demonstrate that the onset of instability can be scaled by including shear dependent rheological properties of the polymer solutions in the nonlinear stability analysis. As a result, a universal criterion as function of normalized polymer concentration is provided for scaling the onset of purely elastic instability in the semidilute regime regardless of the type and molecular weight of the polymer.
More Related Videos
08:42Challenges in Rheological Characterization of Highly Concentrated Suspensions — A Case Study for Screen-printing Silver Pastes
Published on: April 10, 2017
10:28Experimental Measurement of Settling Velocity of Spherical Particles in Unconfined and Confined Surfactant-based Shear Thinning Viscoelastic Fluids
Published on: January 3, 2014
Related Concept Videos
Problem Solving on Stress and Strain
Plastic Behavior
Elastic Strain Energy for Shearing Stresses
Relation between Poisson's ratio, Modulus of Elasticity and Modulus of Rigidity
Molecular Weight of Step-Growth Polymers
As the step-growth polymerization involves step-wise condensation of monomers, the molecular weight also builds up eventually. Consequently, high molecular weight polymers are obtained at the late stages of the polymerization, where 99% of monomers have been consumed.
The extent of the...
Members Made of Elastoplastic Material
As the bending moment...