Significance of electrokinetic characterization for interpreting interfacial phenomena at planar, macroscopic interfaces

Streaming potential measurements provide valuable information for the validation and interpretation of interfacial phenomena that occur at flat macroscopic surfaces. Planar substrates have been extensively used for the interpretation of events, which occur at particulate surfaces; however, these flat surfaces are often only questionably representative of their particulate counterparts due to variations in surface chemistry and topography. In this study, the zeta potential from planar macroscopic surfaces of PMMA, mica, graphite, fluorite, and calcite have been calculated from streaming potentials measured in aqueous solutions using an asymmetric clamping cell. These zeta potentials have been found to significantly contribute to understanding and interpretation of interfacial phenomena influenced by Coulombic interactions including adsorption, surface forces, and the structure of surface micelles.