Electrochemically controlled formation of a silicate membrane at a liquid ∣ liquid interface

A new method is described for the preparation of a silicate membrane. Its principal idea lies in the separation of the template and precursor ions participating in sol–gel processes, by the interface between two immiscible electrolyte solutions (ITIES). The sol–gel process is initiated by potential-controlled adsorption of the template ions at the interface and their transfer from the organic to the aqueous phase. Association of the positive template ions with the silicate ions at the aqueous side of the interface produces neutral species which condense and form a compact layer at the interface. The thickness of the layer can be controlled by the magnitude of the electrical charge passed.