The Structure and Dynamics of Flexible Polyelectrolyte Combs
  The structure and dynamics of a range of polystyrene sulphonate comb polyelectrolytes with well defined chain architectures were examined with static light scattering, dynamic light scattering, small angle neutron/X-ray scattering, particle tracking microrheology and diffusing wave spectroscopy. The chains adopted extended cylindrical conformations in dilute solutions. In semi-dilute solutions a universal behaviour was found for the correlation length (X) on the monomer concentration (c), X=(3.0/b)c^-0.47, independent of the comb architecture (b is the monomer size). The high frequency viscoelasticity (104-106Hz) is found to be in agreement with a model for the Rouse dynamics of the chains and is again independent of the architecture of the combs. However the architecture had a significant impact on the low frequency viscosity of the solutions and the particle tracking data was in good agreement with a dynamic scaling theory for the unentangled dynamics of the combs. Analogous results are found with the biological comb polyelectrolyte aggrecan. 
A. Papagiannopoulos, T. A. Waigh, C. Fernyhough, T. Hardingham, M.   Heinrich