The entropic cost of polymer confinement.

ABSTRACT: The confinement of a polymer into a small space is thermodynamically unfavorable because of the reduction in the number of conformational states. The entropic penalty affects a variety of biological processes, and it plays an important role in polymer transport properties and in microfluidic devices. We determine the entropic penalty for the confinement of elastic polymer of persistence length P in the long-chain limit. We examine three geometries: (1) parallel planes separated by a distance d (a slit); (2) a circular tube of diameter d; and (3) a sphere of diameter d. We first consider infinitely thin (ideal) chains. As d/P drops from 100 to 0.01, TΔS rises from ∼5 × 10(-4) kT to ∼30 kT per persistence length for cases (1) and (2), with the entropic penalty for case (2) being consistently

SUBMITTER: Smyda MR 

PROVIDER: S-EPMC3471378 | biostudies-literature | 2012 Sep

REPOSITORIES: biostudies-literature