Dynamical Scaling in Polymer Solutions Investigated by the Neutron Spin-Echo Technique

Abstract

Applying the recently developed technique of neutron spin-echo spectroscopy, we found it possible to verify unambiguously the scaling predictions of the Zimm model: $\Delta \omega \sim q^3$ for the dynamics of a single chain. At higher polymer concentrations, experimental indications for the predicted crossover to many-chain behavior, which is accompanied by a change in exponent from 3 to 2, were observed. Line-shape analysis rules out a simple exponential decay, indicating the importance of memory effects.