Surfactant Aggregates at a Flat, Isotropic Hydrophobic Surface

We report results of surfactant aggregate morphologies at an amorphous hydrophobic surface whose roughness is small compared to the size of a micelle. Direct imaging by atomic force microscopy shows that single-chain ionic, nonionic, and zwitterionic surfactants, which form spherical micelles in solution, form globular aggregates consistent with half-micelles at an amorphous hydrophobic surface. This result is consistent with the expected isotropy of chain−surface interactions.