Determination of electrostatic potential distribution by atomic force microscopy (AFM) on model silica and alumina surfaces in aqueous electrolyte solutions

- Atomic force microscopy was employed to quantitatively determine the surface potential on silica and alumina surfaces immersed in aqueous electrolyte solutions at various pH values using the DLVO theory.
- Potential distributions could be presented in the form of a potential map by repeating the procedure on multiple locations on these surfaces.
- The average potential of the distributions agreed very well with the surface potentials measured by electrophoretic techniques.
- Several experimental procedures required to achieve the very sensitive force measurements were outlined and demonstrated.