Calculation of parameters of an electrical double layer at the magnetite/solution interface from potentiometric titration data on magnetite suspension

Abstract

A three-layer model of an electrical double layer at magnetite/aqueous 0.001–1 mol/L KCl solution interfaces has been considered in a pH range of 3.5–9.5. A procedure has been proposed for determining the constants of equilibrium reactions and the parameters of electrical double layers from the acid–base potentiometric titration data of magnetite suspensions in the solutions taking into account the generation of a surface charge. The determination of these constants and the parameters of the electrical double layer is based on the use of the point of zero charge. Software has been developed and used for calculating the main parameters of the electrical double layer within the framework of the three-layer model and the Graham–Parsons concepts.