Delay of disorder by diluted polymers

¹ Experimentalphysik, Universität des Saarlandes - 66041 Saarbrücken, Germany
² Institute for Computer Science, Technical University of Czestochowa Armii Krajowej 17, PL 42-200 Czestochowa, Poland

Received: 25 January 2006
Accepted: 9 June 2006

Abstract

We study the effect of diluted flexible polymers on a parametrically driven, disordered capillary wave state. The primary pattern after the first bifurcation from the flat interface is given by squares. With increasing driving strength we observe a melting of the square pattern. Angular and radial correlations are lost and the wave spectrum beyond the basic wave number consists of a continuum only. The addition of a small amount of polymers shifts the disorder transition to higher driving strengths, without affecting the critical acceleration of the first bifurcation. Simultaneously the short wave length —high frequency— fluctuations are suppressed. The effect can be explained only by taking the high elongational viscosity of the polymer solution into account.