The Connection between the Debye and Güntelberg Charging Processes and the Importance of Relative Permittivity: The Ionic Cloud Charging Process

Abstract

The Debye and Güntelberg Charging Processes are essential tools for deriving electrolyte solutions’ activity coefficient models. The Debye–Hückel, Born, and Mean Spherical Approximation are among some famous theories derived via charging processes. How they relate to each other, or if both charging processes are equivalent, or even if both are consistent, has been a matter of discussion in the literature for many years. In this work, we evaluate the results from both charging processes using the Debye–Hückel and the Born equations, using different dependencies of the relative permittivity concerning salt concentration, temperature, and partial charging variable. Our results show that both charging processes are connected through a charging process here called the Ionic Cloud Charging Process. We show how these three charging processes relate to each other, verifying the magnitude of the derivatives of relative permittivity on the final models and their origin from the Ionic Cloud Charging Process.