Simone Melchionna, IPCF - National Research Council, Rome
Dynamics of charged fluids in nanospaces: effect of excluded volume on electrokinetics
I present a theoretical framework to study transport in non-uniform electrolytic solutions and the interplay between structural and ynamical properties varying on the atomic scale. The method bridges different areas of liquid state theory, namely kinetic and density functional theory and is implemented as an effective numerical method via the Lattice Boltzmann approach [1-4]. The method is particularly appealing regarding the applications to fluids confined at nanometric scale, where standard hydrodynamics becomes questionable. In a ternary mixture relevant to electro-osmotic flows, we study the competition between oscillatory density profiles, the structuring due to electrostatic forces and the organization of the velocity field induced by confining walls. The simulations show how excluded volume modulates flow rates at different Debye lengths, surface charge and degree of confinement, together with discriminating electro-osmotic from electrophoretic components at varying packing fractions .
 S. Melchionna and U. Marini Bettolo Marconi, Europhys. Lett. 81, 34001 (2008).  U. Marini Bettolo Marconi and S. Melchionna, J. Chem. Phys. 131, 014105 (2009).  U. Marini Bettolo Marconi and S. Melchionna, J.Phys.: Cond. Matt. 36, 364110 (2010).  U. Marini Bettolo Marconi and S. Melchionna, J. Chem. Phys. 34, 064118 (2011).  S. Melchionna and U. Marini Bettolo Marconi, Europhys. Lett. 95, 44002 (2011).