Dissolution dynamics of NaCl nanocrystal in liquid water

Abstract

The dissolution dynamics of a NaCl nanocrystal in liquid water was studied using molecular dynamics simulations. The dissolution process was found to start with a ${\mathrm{Cl}}^{\ensuremath{-}}$ ion at a corner site, followed by a ${\mathrm{Na}}^{+}$ ion nearby. Both show directional preference in the dissolution path. An ion sequence with alternating charge, i.e., ${\mathrm{Cl}}^{\ensuremath{-}},{\mathrm{Na}}^{+},{\mathrm{Cl}}^{\ensuremath{-}},{\mathrm{Na}}^{+}$, etc. was found to dominate the dissolution process. This image can be understood from the ionic hydration structures and the Coulomb interaction between the ions.