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Fluctuations of a long, semiflexible polymer in a narrow channel.
- Source :
-
Physical review. E, Statistical, nonlinear, and soft matter physics [Phys Rev E Stat Nonlin Soft Matter Phys] 2010 Oct; Vol. 82 (4 Pt 1), pp. 041801. Date of Electronic Publication: 2010 Oct 01. - Publication Year :
- 2010
-
Abstract
- We consider an inextensible, semiflexible polymer or wormlike chain, with persistence length P and contour length L, fluctuating in a cylindrical channel of diameter D. In the regime D<<P<<L , corresponding to a long, tightly confined polymer, the average length of the channel <R(∥)> occupied by the polymer and the mean-square deviation from the average vary as <R(∥)>=[1-α(∘)(D/P)(2/3)]L and <ΔR(∥)(2)>=β(∘)(D(2)P)L , respectively, where α(∘) and β(∘) are dimensionless amplitudes. In earlier work we determined α(∘) and the analogous amplitude α(square) for a channel with a rectangular cross section from simulations of very long chains. In this paper, we estimate β(∘) and β(square) from the simulations. The estimates are compared with exact analytical results for a semiflexible polymer confined in the transverse direction by a parabolic potential instead of a channel and with a recent experiment. For the parabolic confining potential we also obtain a simple analytic result for the distribution of R(∥) or radial distribution function, which is asymptotically exact for large L and has the skewed shape seen experimentally.
Details
- Language :
- English
- ISSN :
- 1550-2376
- Volume :
- 82
- Issue :
- 4 Pt 1
- Database :
- MEDLINE
- Journal :
- Physical review. E, Statistical, nonlinear, and soft matter physics
- Publication Type :
- Academic Journal
- Accession number :
- 21230302
- Full Text :
- https://doi.org/10.1103/PhysRevE.82.041801