Simultaneous Measurements of Interfacial Forces and Electrochemical Reactions in the EC-Surface Forces Apparatus

Recent developments in the SFA technique now allows for (electro)chemical reactions, including oxidation-reduction, adsorption and dissolution, to be quantitatively measured simultaneously with the long-range (e.g., DLVO) or short-range (e.g., adhesion) forces. The EC-attachment involves 3 electrodes at different locations within the SFA chamber, the solution and the surfaces (which can be conducting or non-conducting), and include reference, counter, working, Pt electrodes, etc. Examples will be given of how various electrochemical reactions and effects are being measured, including triboelectrical effects, the phenomenon of Pressure Solution, where one surface causes the dissolution of another nearby surface when there is a natural or applied potential difference between them (analogous to Chemical Mechanical Polishing (CMP), and corrosion), surface roughening or smoothing effects during reactions, flow patterns in thin films induced by electric fields, and oxidation-reduction reactions where the buildup of an oxide layer on one surface with time, coupled to the measured current flowing through the interface allows for the chemical reaction to be uniquely determined.