Topics in the Statistical Physics of Semiflexible Polymers
* SPEAKERS
Name
Affiliation
E-mail
PANAYOTIS BENETATOS
Kyungpook National University
pben(at)knu.ac.kr
* HOST(Applicant)
Name
Affiliation
E-mail
YongSeok Jho
APCTP
ysjho(at)apctp.org
* DATE / TIME
2013-12-12, 16:00
* ABSTRACT
The mechanics of living cells is, to a great extent, determined by the cytoskeleton, a fibrillar network of biopolymers. A common feature of the basic structural elements of the cytoskeleton is their semiflexibility: behavior intermediate between that of random coils and slender rods. The cytoskeletal mechanics is determined by both the single polymer properties and the network-forming linking of many filaments.
In this talk, I will present some recent results on the statistical mechanics of semiflexible polymers. In the first part, I will discuss the problem of a semiflexible chain with uncorrelated quenched disorder in its arc-length-dependent spontaneous curvature and its elastic response to stretching. A formally similar disordered system is a stretched filament subject to random uncorrelated transverse forces (Larkin model). In the second part of the talk, I will present the nonlinear force-extension relation of a bundle of parallel-aligned, strongly stretched semiflexible polymers with chemical (permanent) random cross-links. In the strong stretching limit, the effect of the cross-links is purely entropic. Cross-links suppress thermal fluctuations, thereby enhancing the differential stretching stiffness of the bundle. Close to the gelation transition, the effect of the cross-links on the stretching stiffness of the bundle is similar to that on the shear modulus. In the third part of the talk, we consider an array of weakly bending semiflexible polymers perpendicularly grafted on a substrate. We show that an attractive interaction (which could be due to reversible cross-links) gives rise to a bundling instability to a phase with a periodic modulation of the average in-plane areal density.
