Coarse-grained model of the dynamics of electrolyte solutions
Jack F. Douglas, Marat Andreev, Juan J. de Pablo, Alexandros Chremos
Ion specific solvation has fundamental implications in biochemistry and the thermo- dynamics and dynamics of aqueous salt solutions has correspondingly been investigated intensively. Nonetheless, recent works have indicated fundamental unresolved issues in modeling the dynamics of aqueous salt solutions and the related problem of polymers dissolved in these solutions. In particular, experiments show that the self-diffusion coefficient D of water molecules in electrolyte solutions can be either enhanced or sup-pressed by particular salts having the same valence where the observed changes correlate with the Hofmeister series governing the relative solubility of proteins and water soluble polymers in the same salt solutions.1,2 Recent studies have demonstrated that common atomistic models of aqueous electrolyte solutions completely fail to reproduce this basic phenomenon. Drawing on similar trends observed in the field of polymer nanocomposites, we propose a coarse-grained model of aqueous electrolyte solutions that captures the observed trends and which offers physical insight into the influence of salt on the thermodynamic and dynamic properties of electrolyte solutions.
Journal of Physical Chemistry B
salt, diffusion coefficient, viscosity, entropy-enthalpy compensation, solvation, Born theory