Anomalous lateral diffusion in a viscous membrane surrounded by viscoelastic media
Department of Chemistry, Graduate School of Science and Engineering, Tokyo Metropolitan University Tokyo 192-0397, Japan
2 Physique des Polymères, Université Libre de Bruxelles - Campus Plaine, CP 223, B-1050 Brussels, Belgium, EU
3 National Institute of Advanced Industrial Science and Technology (AIST) - Ibaraki 305-8565, Japan
Accepted: 17 February 2012
We investigate the lateral dynamics in a purely viscous lipid membrane surrounded by viscoelastic media such as polymeric solutions. We first obtain the generalized frequency-dependent mobility tensor and focus on the case in which the solvent is sandwiched by hard walls. Due to the viscoelasticity of the solvent, the mean square displacement of a disk embedded in the membrane exhibits an anomalous diffusion. A useful relation which connects the mean square displacement and the solvent modulus is provided. We also calculate the cross-correlation of the particle displacements which can be applied for two-particle tracking experiments.
PACS: 83.60.Bc – Linear viscoelasticity / 87.16.D- – Membranes, bilayers, and vesicles / 87.16.dp – Transport, including channels, pores, and lateral diffusion
© EPLA, 2012