Molecular Dynamics Simulations of Surfactant\nSelf-Organization at a Solid−Liquid Interface

Abstract

Self-organization of aqueous surfactants at a planar graphite-like surface is studied by means\nof coarse-grain molecular dynamics simulations. The nonionic surfactant, <i>n</i>-alkyl poly(ethylene oxide), and\nwater are both represented by coarse-grain models while an implicit representation is used for the graphite\nsurface. The observed morphology of the aggregated surfactants depends on the alkyl chain length.\nSurfactants with a short chain form a monolayer on the graphite surface with a thickness roughly equal to\nthat of the alkane tail. On the other hand, longer-tail surfactants form continuous hemicylinders on the\nsurface with diameter ∼5.0 ± 0.5 nm, in good agreement with experimental AFM data.