Alladi Ramakrishnan Hall

The Ordinary-Extraordinary Transition in Dynamics of Solutions of Charged Molecules

M. Muthukumar

Polymer Science and Engineering, U of Massachusetts, Amherst, USA

Dynamic light scattering measurements on dilute salt-free polyelectrolyte solutions have shown over the past three decades that there are two distinctive diffusive modes: fast, and slow. The diffusion coefficient deduced from the fast mode has been found to be essentially independent of molar mass and polymer concentration and it is merely a factor of four smaller than that of small electrolyte ion such as sodium or potassium ion. The diffusion coefficient deduced from the slow mode is much smaller suggestive of clumps of many chains although these chains are similarly charged. We will present a theory for these mysterious behaviors of charged systems.