Langmuir−Blodgett Monolayers at a Liquid−Liquid Interface

One of enduring problems of phospholipid adsorption at the interface between two immiscible electrolyte solutions (ITIES) has been the inability to determine and control the exact nature of the adsorbed monomolecular layer. In the present study, this problem has been overcome by the use of the well-known Langmuir−Blodgett technique. It has been shown that reproducible layers of known surface pressure can be deposited at the interface and that the deposition surface pressure has a great influence on the behavior of the layer. Interfacial capacitance data has been extracted and electrocapillary curves have been drawn. The noted shift in the electrocapillary minimum and the lowered interfacial capacitance have been explained by use of a simple electrostatic model. Probe ion transfer studies show no change in the interfacial kinetics or in the Gibbs free energy of transfer.