Gibbs Free Energy Implications of Electric Double Layer for Wettability Trend in Geologic Carbon Storage

Abstract

In this paper, we demonstrated the theoretical relationship between Gibbs free energy of the electric double layer and aqueous solution pH. The basis for our theoretical derivation is the fundamental electrochemical equation of Nernst and the Gouy Chapman theory of the electric double layer. In the thermodynamic sense, the partial derivative of Gibbs free energy with regard to interface/surface area is shown to directly linked to interfacial or surface energy, where the former is pH dependent. Accordingly, our theoretical derivation has permitted the interpretation of wettability trends in saline aquifers under geological carbon storage.