Indexed on: 18 Jan '18Published on: 18 Jan '18Published in: arXiv - Physics - Soft Condensed Matter
We use Brownian dynamics to show: For an isolated polymer coil, the Kirkwood-Riseman model for chain motion is qualitatively correct. The Rouse model for chain motion is qualitatively incorrect. The models are qualitatively different. Kirkwood and Riseman say polymer coils in a shear field perform whole-body rotation; in the Rouse model rotation does not occur. Our simulations demonstrate that in shear flow: Polymer coils rotate. Rouse modes are cross-correlated. The amplitudes and relaxation rates of Rouse modes depend on the shear rate. Rouse's calculation only refers to a polymer coil in a quiescent fluid, its application to a polymer coil undergoing shear being invalid.