Dresden 2006 – wissenschaftliches Programm

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CPP: Chemische Physik und Polymerphysik

CPP 10: POSTER Nonequilibrium Phenomena in Soft Condensed Matter

CPP 10.7: Poster

Dienstag, 28. März 2006, 17:00–19:00, P3

Friction of macromolecules in solution: Effects of high–order correlations. — •Alexander Uvarov and Stephan Fritzsche — Universität Kassel, D–34132 Kassel, Germany

Apart from the rotational and translational motion of macromolecules, the concept of friction have been found helpful to understand their shape as well as the formation and deformation of such macromolecules. During the past decade, therefore, a large number of experiments and molecular dynamic (MD) simulations have been carried out to understand the friction properties of macromolecules. An alternative treatment of such molecules is based on statistical methods, if they are described in terms of their molecular subsystems, (beads), and if the influence of the solvent particles on the dynamics of the macromolecule is incorporated into the friction tensors of the macromolecule [1].

In this contribution we derived and explain the explicit expression for the friction tensors which can be applied in order to calculate the diffusion coefficient as function of the mass ratio of the molecules, relative to the mass of the solvent particles. In addition, we also discuss the effects of the transition between slip and stick boundary conditions by calculating the boundary condition coefficient of the macromolecule for different mass ratios as well as different bead–solvent potentials. The results from this semi–phenomenological theory are found to compare very well with MD simulations over a wide range of mass ratios [2].

[1] A. Uvarov and S. Fritzsche, Phys. Rev. E, accepted (2005); 

[2] J. R. Schmidt, J. L. Skinner, J. Phys. Chem. B. 108, 6767 2004.