Dynamics of diffusion controlled chain closure: flexible chain in presence of hydrodynamic interaction

TL;DR

This study investigates how hydrodynamic interactions influence the ring closing dynamics of flexible chains in theta solvents, revealing that such interactions generally accelerate closure for longer chains and confirming a specific scaling law.

Contribution

It extends the Wilemski-Fixman approach to include hydrodynamic interactions, demonstrating their effect on chain closure times and confirming a predicted scaling law.

Findings

Hydrodynamic interactions speed up ring closure for longer chains.

Ring closing time scales with chain length as N^1.527.

Results agree with previous renormalization group predictions.

Abstract

Based on the Wilemski-Fixman approach (J. Chem. Phys. 60, 866 (1974)) we showed that for a flexible chain in theta solvent hydrodynamic interaction treated with an pre-averaging approximation makes ring closing faster if the chain is not very short. Only for a very short chain the ring closing is slower with hydrodynamic interaction on. We have also shown that the ring closing time for a chain with hydrodynamic interaction in theta solvent scales with the chain length (N) as N^(1.527), in good agreement with previous renormalization group calculation based prediction by Freidman et al. (Phys. Rev. A. 40, 5950 (1989)).