Mesoscale modelling of polyelectrolyte electrophoresis - Condensed Matter > Soft Condensed MatterReportar como inadecuado

Mesoscale modelling of polyelectrolyte electrophoresis - Condensed Matter > Soft Condensed Matter - Descarga este documento en PDF. Documentación en PDF para descargar gratis. Disponible también para leer online.

Abstract: The electrophoretic behaviour of flexible polyelectrolyte chains ranging fromsingle monomers up to long fragments of hundred repeat units is studied by amesoscopic simulation approach. Abstracting from the atomistic details of thepolyelectrolyte and the fluid, a coarse-grained molecular dynamics modelconnected to a mesoscopic fluid described by the Lattice Boltzmann approach isused to investigate free-solution electrophoresis. Our study demonstrates theimportance of hydrodynamic interactions for the electrophoretic motion ofpolyelectrolytes and quantifies the influence of surrounding ions. Thelength-dependence of the electrophoretic mobility can be understood byevaluating the scaling behavior of the effective charge and the effectivefriction. The perfect agreement of our results with experimental measurementsshows that all chemical details and fluid structure can be safely neglected,and a suitable coarse-grained approach can yield an accurate description of thephysics of the problem, provided that electrostatic and hydrodynamicinteractions between all entities in the system, i.e., the polyelectrolyte,dissociated counterions, additional salt and the solvent, are properlyaccounted for. Our model is able to bridge the single molecule regime of a fewnm up to macromolecules with contour lengths of more than 100 nm, a lengthscale that is currently not accessible to atomistic simulations.

Autor: Kai Grass, Christian Holm


Documentos relacionados