Self-assembly of a nonionic surfactant at the graphite/ionic liquid interface

In this study, we demonstrate by AFM imaging that nonionic surfactants self-assemble into hemicylindrical aggregates at the interface between graphite and the room temperature ionic liquid ethylammonium nitrate. Like aqueous systems, surfactant first adsorbs in a tail-to-tail monolayer arrangement along one of the three symmetry axes of graphite, templating subsequent self-assembly into adsorbed hemicylinders. Longer surfactant tails and higher concentrations are required to produce hemicylindrical aggregates in the ionic liquid than in aqueous solutions. Copyright © 2005 American Chemical Society.