Abstract
Molecular dynamics simulations of the magnetite-water interface with eluted ions(Fe^<2+>, Fe(OH)_2 ) were performed in order to estimate free energy profile of the ions across the interface. The purpose of examining the free energy profile is to discuss mass transfer characteristics in the vicinity of interface. The free energy profile was calculated by using the umbrella sampling and WHAM procedure. From the calculation, we show that in the case of Fe^<2+> ion, a high free energy barrier exist at the solvent surface. On the other hand, in the case of Fe(OH)_2, the free energy barrier is not recognized because the strong coulomb interaction between hydroxyl group of Fe(OH)_2 and the magnetite surface contributes decrease of the energy barrier.
