Computer Simulation Studies of Ion Transport across a Liquid/Liquid Interface

The mechanism for transporting a chloride ion or a cesium ion across a water−carbon tetrachloride liquid/liquid interface is characterized using molecular dynamics techniques. The results obtained in these studies provided new physical insight into both the free energies and solvent structures as the ion moved across the interface. The computed free-energy profiles of ion transfer for both ions increased monotonically from water to carbon tetrachloride. No free-energy minima were observed at the liquid/liquid interface. The first hydration shells of the ions were significantly reduced as the ions moved from the aqueous phase to the nonaqueous phase. A so-called “fingering” was created by the chloride ion in the nonaqueous phase, which has a similar characteristic found in the aqueous ionic cluster studies.