Polymer dynamics in solution Universal properties vs. individual behaviour in a unified approach

Abstract

The main factors affecting the dynamics of polymer chains in dilute solution are reviewed. We consider both the collective properties of the chain that follow relatively simple universal laws and the local properties related to the chain stereochemistry. Good-solvent expansion and hydrodynamic interaction are discussed for chains of different architecture, in particular linear and regular star polymers, starting from the usual Rouse–Zimm approach. We also include in the dynamic equations the effect of the local chain stiffness, arising from (i) the equilibrium configurational properties of the chain and (ii) the energy barriers to skeletal rotations hindering the propagation of conformational rearrangements along the chain backbone. The quantities taken into consideration are the intrinsic viscosity and the hydrodynamic radius, compared with the radius of gyration, as well as the complex modulus measured under an oscillating shear deformation, and the dynamic structure factor measured through quasi-elastic scattering. As an example of non-equilibrium behaviour, we discuss a theoretical investigation of the kinetics of chain contraction to a compact globular state following a sudden change in solvent quality.