Eur. Phys. J. E (2011) 34: 46
https://doi.org/10.1140/epje/i2011-11046-3

Dynamics of a polymer chain confined in a membrane

¹ Department of Chemistry, Graduate School of Science and Engineering, Tokyo Metropolitan University, 192-0397, Tokyo, Japan
² National Institute of Advanced Industrial Science and Technology, 305-8565, Ibaraki, Japan
³ Institut für Festkörperforschung, Forschungszentrum Jülich, D-52425, Jülich, Germany

^* e-mail: komura@tmu.ac.jp

Received: 28 June 2010
Revised: 18 December 2010
Accepted: 30 March 2011
Published online: 11 May 2011

Abstract

We present a Brownian dynamics theory with full hydrodynamics (Stokesian dynamics) for a Gaussian polymer chain embedded in a liquid membrane which is surrounded by bulk solvent and walls. The mobility tensors are derived in Fourier space for the two geometries, namely, a free membrane embedded in a bulk fluid, and a membrane sandwiched by the two walls. Within the preaveraging approximation, a new expression for the diffusion coefficient of the polymer is obtained for the free-membrane geometry. We also carry out a Rouse normal mode analysis to obtain the relaxation time and the dynamical structure factor. For large polymer size, both quantities show Zimm-like behavior in the free-membrane case, whereas they are Rouse-like for the sandwiched membrane geometry. We use the scaling argument to discuss the effect of excluded-volume interactions on the polymer relaxation time.