Evidence for a Diffuse Interfacial Region at the Dichloroethane/Water Interface

The 1,2-dichloroethane (DCE)/water interface is important because of its suitability as an electrochemical interface between two immiscible electrolyte solutions (ITIES). An issue of particular interest is whether the interfacial region is molecularly sharp or whether the interface is comprised of a diffuse mixed interfacial region. These studies using vibrational sum-frequency spectroscopy as a probe of the structure, orientation, and bonding of interfacial water show that the interface is molecularly disordered with properties similar to a mixed phase interfacial region. It does not have the characteristics of a sharp interface that have been shown to occur at other liquid/liquid interfaces such as CCl4/H2O and alkane/H2O.