Polymer chain in a quenched random medium: slow dynamics and ergodicity breaking |
| |
Authors: | G Migliorini VG Rostiashvili TA Vilgis |
| |
Institution: | (1) Max Planck Institute for Polymer Research 10 Ackermannweg, 55128 Mainz, Germany, DE;(2) Laboratoire Européen Associé, Institut Charles Sadron 6 rue Boussingault, 67083 Strasbourg Cedex, France, FR |
| |
Abstract: | The Langevin dynamics of a self-interacting chain embedded in a quenched random medium is investigated by making use of the
generating functional method and one-loop (Hartree) approximation. We have shown how this intrinsic disorder causes different
dynamical regimes. Namely, within the Rouse characteristic time interval the anomalous diffusion shows up. The corresponding
subdiffusional dynamical exponents have been explicitly calculated and thoroughly discussed. For the larger time interval
the disorder drives the center of mass of the chain to a trap or frozen state provided that the Harris parameter, (Δ/b
d)N
2 - νd≥1, where Δ is a disorder strength, b is a Kuhnian segment length, N is a chain length and ν is the Flory exponent. We have derived the general equation for the non-ergodicity function f (p) which characterizes the amplitude of frozen Rouse modes with an index p = 2πj/N. The numerical solution of this equation has been implemented and shown that the different Rouse modes freeze up at the same
critical disorder strength Δ
c ∼ N
- γ where the exponent γ ≈ 0.25 and does not depend from the solvent quality.
Received 17 December 2002 Published online 23 May 2003
RID="a"
ID="a"e-mail: vilgis@mpip-mainz.mpg.de |
| |
Keywords: | PACS 61 25 Hq Macromolecular and polymer solutions polymer melts swelling – 78 55 Qr Amorphous materials glasses and other disordered solids – 66 90 +r Other topics in nonelectronic transport properties of condensed matter |
本文献已被 SpringerLink 等数据库收录! |
|