Importance of hydrodynamic shielding for the dynamic behavior of short polyelectrolyte chains

TL;DR

This study demonstrates that hydrodynamic shielding significantly influences the dynamic behavior of short polyelectrolyte chains, with simulations aligning well with experimental data when hydrodynamic interactions are included.

Contribution

It is the first to explicitly show that hydrodynamical shielding causes the maximum in electrophoretic mobility of short polyelectrolytes.

Findings

Hydrodynamic interactions are crucial for accurate modeling.

Electrophoretic mobility peaks due to hydrodynamical shielding.

Coarse-grained models can effectively simulate polyelectrolyte dynamics.

Abstract

The dynamic behavior of polyelectrolyte chains in the oligomer range is investigated with coarse-grained molecular dynamics simulation and compared to data obtained by two different experimental methods, namely capillary electrophoresis and electrophoresis NMR. We find excellent agreement of experiments and simulations when hydrodynamic interactions are accounted for in the simulations. We show that the electrophoretic mobility exhibits a maximum in the oligomer range and for the first time illustrate that this maximum is due to the hydrodynamical shielding between the chain monomers. Our findings demonstrate convincingly that it is possible to model dynamic behavior of polyelectrolytes using coarse grained models for both, the polyelectrolyte chains and the solvent induced hydrodynamic interactions.