Viscoelasticity of dilute solutions of semiflexible polymers - art. no. 020802

We show using Brownian dynamics simulations and theory how the shear relaxa tion modulus G(t) of dilute solutions of relatively stiff semiflexible poly mers differs qualitatively from that of rigid rods. For chains shorter than their persistence length, G(t) exhibits three time regimes: At very early times, when the longitudinal deformation is affine, G(t)similar tot(-3/4). Over a broad intermediate regime, during which the chain length relaxes, G( t) similar to t(-5/4). At long times, G(t) mimics that of rigid rods. A mod el of the polymer as an effectively extensible rod with a frequency depende nt elastic modulus B(omega)similar to (i omega)(3/4) quantitatively describ es G(t) throughout the first two regimes.