Design and Prediction of Corrosion Inhibitors from Quantum Chemistry: II. A General Framework for Prediction of Effective Oil/Water Partition Coefficients and Speciation from Quantum Chemistry

Abstract

Quantum chemistry is a powerful tool for computing the properties of molecules and their interactions with one another in a variety of environments. In this second paper of a two-part series, the technique is applied in this work to calculate fundamental properties of inhibitor molecules important to the overall corrosion inhibitor performance. The study focuses on the issue of oil/water partitioning as quantified by the partition coefficient (log P) and the important issue of inhibitor speciation according to the acid dissociation constant (pKa). pKa and log P values are then calculated from first-principles for a series of imidazole derivatives and integrated into a model for inhibitor availability as a function of the water cut. Applications to lifetime prediction and inhibitor design are then discussed.