Scaling of dynamics in 2d semi-dilute polymer solutions

• Published in: Europhysics letters Vol. 68; no. 1; pp. 65 - 71
• Main Authors: Cicuta, P, Hopkinson, I
• Format: Journal Article
• Language: English
• Published: IOP Publishing 01.10.2004; EDP Sciences
• Subjects: 68.03.Cd; 83.85.Ei
• ISSN: 0295-5075; 1286-4854
• DOI: 10.1209/epl/i2004-10166-9

We consider the dynamics of thermal concentration fluctuations in polymer Langmuir monolayers, probed with surface light scattering. We present data on the proteins β-lactoglobulin and β-casein and on the synthetic polymers Poly(vinyl acetate) and Poly(4-hydroxystyrene). We show that for all these systems, in the semi-dilute concentration regime, there is a power law dependency of both the elastic and viscous components of the dilational modulus on the concentration. We find that for all the systems considered, the viscosity scales with a power that is double that of the elasticity. A simple explanation for this universal dynamical behavior in semidilute polymer monolayers is suggested.