We use off-lattice, pruned-enriched Rosenbluth method simulations to compute the confinement free energy of a real wormlike chain of effective width w and persistence length lp in a slit of height H. For slit heights much larger than the persistence length of the polymer and much smaller than the thermal blob size, the excess free energy of the confined chain is consistent with a modified version of the scaling theory for the extended de Gennes regime in a channel that reflects the blob statistics in slit confinement. Explicitly, for channel sizes 2lp H 0.2lp2/w, the difference between the confinement free energy of the real chain and that of an ideal chain scales like w/H.
Bibliographical noteFunding Information:
This work was supported by the National Institutes of Health (R01-HG006851). Computational resources were provided in part by the University of Minnesota Supercomputing Institute. We thank Liang Dai for useful discussions concerning Ref.