Eur. Phys. J. E (2014) 37: 10
https://doi.org/10.1140/epje/i2014-14010-9

Regular Article

Liquid filament instability due to stretch-induced phase separation in polymer solutions

Liquid filament instability

¹ Laboratory of polymer rheology, Institute of Petrochemical Synthesis, Russian Academy of Sciences, 29 Leninkii prospect, 119991, Moscow, Russian Federation
² Department of Mechanical Engineering, Technion - Israel Institute of Technology, 32000, Haifa, Israel

^* e-mail: mearin@techunix.technion.ac.il

Received: 10 October 2013
Revised: 29 January 2014
Accepted: 12 February 2014
Published online: 25 February 2014

Abstract

The instability in a jet of a viscoelastic semidilute entangled polymer solution under high stretching is discussed. Initially the jet is stable due to solution elasticity stopping the fluctuation growth. The modeling shows that a jet stretching results in a radial gradient in the polymer distribution: the polymer is concentrated in the jet centre, whereas the solvent is remaining near the surface. This viscous liquid shell demonstrates Raleigh-type instability resulting in the formation of individual droplets on the oriented filament. All process stages were observed experimentally.