Computational Prediction of the Adsorption Equilibrium for Ionic Surfactants at the Electrified Oil/Water Interface.

In a previous study (Somekawa et al. Langmuir2019, 35, 11345–11350) a non‐Bornian solvation model was successfully applied to computational prediction of the adsorption equilibrium for nonionic surfactants at the oil (O)/water (W) interface. In this study, the method was extended to the adsorption of "ionic" surfactants at the polarized O/W interface. In this extension, the electrostatic potential of an ionic surfactant in the electric double layer formed at the O/W interface was taken into account together with the chemical potential estimated using the non‐Bornian solvation model. The calculation results clearly showed that a cationic surfactant (hexadecyltrimethylammonium ion) was adsorbed at the nitrobenzene/W interface, when the interfacial potential was negative. This prediction was consistent with the previous experimental observation using electrocapillary measurements. [ABSTRACT FROM AUTHOR]