Tortured Chains: An Introduction

A flexible chain is very sensitive to motions of the surrounding solvent. For a single chain floating in a low molecular weight solvent, the response to weak flows was analyzed long ago by the great pioneers: Zimm, Peterlin,... [1,2] and determined experimentally by low frequency acoustic measurements [3]. The first basic feature is a relaxation time T z : (n: solvent viscosity, R: coil radius, kT: thermal energy) and the weak flow regime corresponds to shear rates.