A semi-phenomenological approach to the transport and diffusion of small spherical macromolecules in solution

A recently derived expression [A. Uvarov, S. Fritzsche, Macromol. Theor. Simul. 13 (2004) 241] for the friction coefficient of macromolecules, which are immersed into a solution, is utilized in order to calculate their diffusion and boundary condition coefficients as function of the mass ratio of the molecules, relative to the mass of the solvent particles. The results from this semi-phenomenological theory are found to compare very well with molecular-dynamical simulations over a wide range of mass ratios and at quite different temperatures and viscosities of the solvent. Therefore, the use of this novel approach may help reduce considerably the costs in studying the dynamical behaviour and the transport properties of macromolecules in solution.