Partitioning of semiflexible macromolecules into a slit in good solvents

We investigate by Monte Carlo simulations the partitioning of semiflexible chains into slits the sizes of which are in the range of coil dimensions. T he investigated chains have variable rigidities within the coil regime nor reaching the rigid rod limit. Noticeable deviations of the commonly used ap proximate persistence length from its exact counterpart are reported. The p artitioning of semiflexible chains in the reduced plot of partitioning coef ficient versus confinement is located between the results for the partition ing of a sphere and for a rigid rod. At large confinement, and for the most rigid chains investigated, the scaling law for partitioning approaches tha t of the rigid rods. We advocate presenting results based both on the reduc ed and absolute plots for drawing the correct conclusions. On increasing co ncentration, it is apparent that the differences in partitioning resulting from variable chain rigidity appear only in the dilute solution. At higher concentrations the differences vanish. The weak-to-strong penetration trans ition on an increase of concentration is explained using the scaling approa ch by the change of the mobility unit from the coil dimension to a concentr ation correlation length, similarly to that of flexible chains. The microsc opic picture of partitioning represented by various concentration profiles in the slit leads to the conclusion that stiffer chains are able to fill th e depletion layer at the wails more readily.