Specific Ion Adsorption and Surface Forces in Colloid Science

Abstract

Mean-field theories that include nonelectrostatic interactions acting on ions near interfaces have been found to accommodate many exptl. obsd. ion specific effects. However, it is clear that this approach does not fully account for the liq. mol. structure and hydration effects. This is now improved by using parametrized ionic potentials deduced from recent nonprimitive model mol. dynamics (MD) simulations in a generalized Poisson-Boltzmann equation. We investigate how ion distributions and double layer forces depend on the choice of background salt. There is a strong ion specific double layer force set up due to unequal ion specific short-range potentials acting between ions and surfaces.