Quantitatively Accurate Theory to Predict Adsorbed Configurations of Surfactants on Metal Surfaces*

We have developed a theoretical model to predict adsorbed configurations of surfactant molecules on metal surfaces. Coarse-grained simulations of adsorption of surfactants show that our theoretical model is quantitatively accurate in predicting adsorbed configurations. We show that depending on the relative interaction strengths of the polar group and the alkyl tails with the metal surface, the surfactant molecules either adsorb by lying parallel to the surface to form stripes or adsorb perpendicular to the surface to form a monolayer. In the case of monolayer formation, our theory predicts that adsorbed surfactant molecules will undergo an orientational transition.  This orientational transition is observed in our simulations and have also been reported in experiments.