Dynamics of rodlike macromolecules in semidilute solutions

Experimental data on the rotation and translation of rigid rod macromolecules in the semi-dilute region are discussed in the terms of the Doi-Edwards theory. Available data indicate that the rotational diffusion coefficients vary approximately as the inverse concentration squared and the inverse length to a power between 7 and 8. The absolute value of the decrease of the rotational diffusion coefficient in the semidilute region relative to the infinite dilution value is about two orders of magnitude less than is predicted by the Doi-Edwards theory. Some possible explanations for these deviations include: