PNNL

Abstract

Buried liquid-liquid interfaces, like the oil-water interface, can be probed in great detail, by recreating them synthetically via cryogenic molecular beam epitaxy. The structures placed within them persist long enough, once one warms the system to restore true fluidity, to probe many properties. Further, by gently (>1 eV) imbedding tracer ions (like hydronium or cesium) with angstrom precision at, below, and/or above the interface, it becomes possible to study kinetic processes with high precision. We use it to measure the solvation chemical potential of an ion in the oil versus position near the water interface. We also measure the interface-induced fluidity changes