  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.
